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1
Tangerina, Marcelo Marucci Pereira [UNESP]. « Extratos padronizados para o tratamento de doenças crônicas : Machaerium hirtium ». Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/97015.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
O uso de fitoterápicos padronizados com assegurada comprovação de eficácia e segurança tem apresentado resultados terapêuticos surpreendentes em diversos países. Contudo, no Brasil, onde há grande potencial de produção de fitoterápicos devido a sua enorme biodiversidade, há deficiências na correta caracterização química das matérias-primas e escassez de ensaios farmacológicos e toxicológicos desses materiais, etapas essenciais para assegurar eficácia e segurança dos fitoterápicos. Machaerium hirtum (Fabaceae) é utilizada popularmente para o tratamento de diarréia, tosse e câncer. Um estudo químico que identifique as substâncias presentes nesta espécie e as quantifique pode fornecer subsídios para o entendimento destas atividades. A primeira etapa consistiu no isolamento das substâncias do extrato EtOH 70% das partes aéreas de M. hirtum por meio de cromatografia de permeação em gel seguida de purificação das substâncias por HPLC-RI. A identificação das substâncias foi feita por Ressonância Magnética Nuclear e por Espectrometria de Massas. O perfil químico do extrato foi estabelecido por HPLC-PDA e a quantificação das substâncias foi feita com base em suas agliconas, pelo método da calibração externa. Foi possível identificar as flavonas saponarina (8,69 ± 0,46 mg/g de extrato), isovitexina (6,44 ± 0,45 mg/g de extrato), isoorientina, que se apresentou abaixo do limite de quantificação (LOQ) e swertisina, presente no perfil cromatográfico em co-eluição com outra substância. Tais resultados são fundamentais para a padronização do extrato EtOH 70% das folhas de Machaerium hirtum
The use of standardized phytomedicines with proven efficacy and safety has shown surprising therapeutic results in various countries. Brazil has great potential for production of herbal medicine due to its enormous biodiversity. However, there are deficiencies in the correct characterization of chemical raw materials and few reliable pharmacological and toxicological tests of these materials, essential steps to ensure efficacy and safety of herbal medicines. Machaerium hirtum (Fabaceae) is popularly used to treat diarrhea, cough and cancer. A chemical study to identify the substances present in this species may provide and quantify contributions to the understanding of these activities. The first step was the isolation of substances of 70% EtOH extract of aerial parts of M. hirtum by gel permeation chromatography followed by purification of substances by HPLC-RI. The identification of substances was performed by Nuclear Magnetic Resonance and Mass Spectrometry. The chemical profile of the extract was established by HPLC-PDA and quantification of the substances was based on their aglycones by the method of external calibration. It was possible to identify the flavones saponarin (8,69 ± 0,46 mg/g of extract), isovitexin (6,44 ± 0,45 mg/g of extract), isoorientin, which was below the limit of quantification (LOQ) and swertisin, present in the chromatographic profile in co-elution with another substance. These results are fundamental to the standardization of the crude 70% EtOH extract from the leaves of Machaerium hirtum
2
Arantes, Glenda Marqueti [UNESP]. « Bioprospecção em espécies do gênero Sclerolobium sp : busca de agentes quimiopreventivos ». Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/105818.
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A família Fabaceae é subdividida em 3 subfamílias: Faboideae, Caesalpinoideae e Mimosoideae, que englobam mais de 700 gêneros e 18000 espécies, bem distribuídas nas regiões tropicais e subtropicais. Inclui espécies de alta relevância econômica, como a soja, feijão, cerejeira, angelim e sucupira, além do pau-brasil, de importância histórica para o Brasil. Neste trabalho, os extratos etanólicos das folhas de Sclerolobium aureum, S. denudatum e S. paniculatum mostraram forte potencial antioxidante, sendo selecionados para investigação fitoquímica detalhada. O fracionamento cromatográfico destes extratos evidenciou sua composição química, destacando-se a presença de esqualeno, tocoferóis e lupenona, identificados por CG-EM, predominantes nas frações de baixa polaridade. O extrato hidroalcoólico de S. aureum foi submetido a etapas de purificação, incluindo o uso de CLAE-UV-DAD, evidenciando a presença majoritária de ácido gálico, flavonoides monoglicosilados e catequina, identificados por RMN, EM e UV. Os extratos hidroalcoólicos de S. denudatum e S. paniculatum foram submetidos a partição líquido-líquido e as frações resultantes foram analisadas por CLAE-UV-DAD e CLAE-EM-EM para identificação dos seus constituintes por desreplicação, ou seja, evitando-se procedimentos de purificação de substâncias conhecidas. Esta estratégia permitiu conhecer os metabólitos secundários das três espécies, que apresentaram perfis químicos semelhantes com a predominância de flavonoides monoglicosilados. As frações semipurificadas e substâncias isoladas mostraram elevado potencial de sequestro de radicais livres frente ao DPPH, destacando-se a presença de antioxidantes lipofílicos e hidrofílicos, atrativa para aplicações em cosméticos. Adicionalmente, foi observado potencial imunomodulador...
Fabaceae family comprises 3 subfamilies: Faboideae, Caesalpinoideae and Mimosoideae, with more than 700 genera and 18000 species, widespread in tropical and subtropical regions. It includes economically important species as soybean, beans, angelim, sucupira, in addition to pau-brasil (Caesalpinea echinata), which has historical importance in Brazil for its wood pigments. In this work, ethanol extracts of Sclerolobium aureum, S. denudatum and S. paniculatum leaves were investigated and showed strong antioxidant potential, and were selected for further investigation. Their chromatographic fractionation evidenced the presence of squalene, tocopherols and lupenone as major compounds in low polarity fractions, by GC-MS analysis. The hydroalcoholic extract of S. aureum was submitted to purification procedures, including the use of HPLC-UV-DAD, which evidenced gallic acid, flavonoid monoglucosides and catechin as major compounds, identified mainly by NMR, MS and UV techniques. HPLC-UV-DAD and LC-MS-MS analysis were further carried out on the hydroalcoholic extract of S. denudatum and S. paniculatum, leading to the identification of their major constituents by dereplication, avoiding the purification of known compounds. Such strategy evidenced a similar chemical profile for the three Sclerolobium species, with flavonoid monoglucosides as major compounds. Strong free radical scavenging potential was observed for the fractions and isolated compounds towards DPPH, evidencing the presence of lipophilic and hydrophilic antioxidants, which might be important for cosmetics development. In addition, the immunomodulatory potential of the hexane and ethyl acetate fractions from S. denudatum were evidenced through the dose-dependent inhibition of nitrite release by pre-treated macrophages, which might... (Complete abstract click electronic access below)
3
Tangerina, Marcelo Marucci Pereira. « Extratos padronizados para o tratamento de doenças crônicas : Machaerium hirtium / ». Araraquara : [s.n.], 2012. http://hdl.handle.net/11449/97015.
Texte intégralRésumé :
Orientador: Wagner VilegasCoorientador: Miriam Sannomiya
Banca: Alba Regina Monteiro Souza Brito
Banca: Elfriede Marianne Bacchi
Resumo: O uso de fitoterápicos padronizados com assegurada comprovação de eficácia e segurança tem apresentado resultados terapêuticos surpreendentes em diversos países. Contudo, no Brasil, onde há grande potencial de produção de fitoterápicos devido a sua enorme biodiversidade, há deficiências na correta caracterização química das matérias-primas e escassez de ensaios farmacológicos e toxicológicos desses materiais, etapas essenciais para assegurar eficácia e segurança dos fitoterápicos. Machaerium hirtum (Fabaceae) é utilizada popularmente para o tratamento de diarréia, tosse e câncer. Um estudo químico que identifique as substâncias presentes nesta espécie e as quantifique pode fornecer subsídios para o entendimento destas atividades. A primeira etapa consistiu no isolamento das substâncias do extrato EtOH 70% das partes aéreas de M. hirtum por meio de cromatografia de permeação em gel seguida de purificação das substâncias por HPLC-RI. A identificação das substâncias foi feita por Ressonância Magnética Nuclear e por Espectrometria de Massas. O perfil químico do extrato foi estabelecido por HPLC-PDA e a quantificação das substâncias foi feita com base em suas agliconas, pelo método da calibração externa. Foi possível identificar as flavonas saponarina (8,69 ± 0,46 mg/g de extrato), isovitexina (6,44 ± 0,45 mg/g de extrato), isoorientina, que se apresentou abaixo do limite de quantificação (LOQ) e swertisina, presente no perfil cromatográfico em co-eluição com outra substância. Tais resultados são fundamentais para a padronização do extrato EtOH 70% das folhas de Machaerium hirtum
Abstract: The use of standardized phytomedicines with proven efficacy and safety has shown surprising therapeutic results in various countries. Brazil has great potential for production of herbal medicine due to its enormous biodiversity. However, there are deficiencies in the correct characterization of chemical raw materials and few reliable pharmacological and toxicological tests of these materials, essential steps to ensure efficacy and safety of herbal medicines. Machaerium hirtum (Fabaceae) is popularly used to treat diarrhea, cough and cancer. A chemical study to identify the substances present in this species may provide and quantify contributions to the understanding of these activities. The first step was the isolation of substances of 70% EtOH extract of aerial parts of M. hirtum by gel permeation chromatography followed by purification of substances by HPLC-RI. The identification of substances was performed by Nuclear Magnetic Resonance and Mass Spectrometry. The chemical profile of the extract was established by HPLC-PDA and quantification of the substances was based on their aglycones by the method of external calibration. It was possible to identify the flavones saponarin (8,69 ± 0,46 mg/g of extract), isovitexin (6,44 ± 0,45 mg/g of extract), isoorientin, which was below the limit of quantification (LOQ) and swertisin, present in the chromatographic profile in co-elution with another substance. These results are fundamental to the standardization of the crude 70% EtOH extract from the leaves of Machaerium hirtum
Mestre
4
Coqueiro, Aline [UNESP]. « Fracionamento bioguiado para selação de substâncias antioxidante, antimalárica e antibiótica potenciais nas espécies Kielmeyera variabilis (Clusiaceae) e Brosimum Glaziovii (Moraceae) ». Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/105815.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Os testes biológicos realizados por pesquisadores colaboradores do NuBBE para as espécies selecionadas para este estudo Brosimum glaziovii e Kielmeyera variabilis indicaram K. variabilis como uma importante fonte de metabólitos especiais bioativos. O fracionamento bioguiado da fração AcOEt dos galhos de K. variabilis para isolamento de substâncias com potencial antimalárico foi realizado via teste químico com -hematina e in vitro com Plasmodium falciparum, levando a identificação das xantonas oxigenadas 3,6-diidroxi-1,4,8-trimetoxixantona, 3,5-diidroxi-4-metoxixantona, 3,4-diidroxi-6,8-dimetoxixantona, 3,4-diidroxi-2-metoxixantona, 5-hidroxi-1,3- dimetoxixantona, 2,3-dimetoxi-4-hidroxixantona, 3-hidroxi-2-metoxixantona e 2-hidroxi- 1-metoxi-xantona e o xantonolignóide kielcorina. Dentre as substâncias isoladas, o xatonolignóide kielcorina foi considerado ativo quando comparado ao padrão cloroquina. A avaliação do potencial tripanocida também foi realizada para as xantonas isoladas e dentre estas, a 3,4-diidroxi-2-metoxixantona foi a mais ativa, principalmente para a cepa resistente ao benzonidazol (cepa Bolívia). Na fração EHFB das folhas de B. glaziovii foi observado o potencial antichagásico desta espécie. Os resultados observados para os ensaios antioxidantes levaram ao isolamento dos flavonóides quercitrina, podocarpusflavona A e da mistura de quercetina-3-Oglicosídeo e quercetina-3-O-galactosídeo, evidenciando a importância dos grupos catecólicos na potencialização da ação antioxidante. O estudo bioguiado pela atividade antimicrobiana com seis cepas de Staphylococcus aureus resistentes à meticilina culminou no isolamento de um derivado prenilado do floroglucinol (HGK-1) o qual demonstrou ser responsável pela potente atividade demonstrada pela fração hexânica dos galhos de K. variabilis. As xantonas isoladas tiveram seu potencial antimicrobiano...
Several biological activities have been carried out by NuBBE’s collaborators aiming the identification of active extracts from plant species, and Brosimum glaziovii and Kielmeyera variables showed to be important sources of bioactive secondary metabolites. Bio-guided fractionation of the EtOAc bioactive fraction of the branches of K. variabilis by using of the chemical test -hematin, and in vitro by using of Plasmodium falciparum, led to the isolation and identification of oxygenated xanthones 3,6-dihydroxy-1,4,8-trimethoxyxanthone, 3,5-dihydroxy-4-methoxyxanthone, 3,4- dihydroxy-6,8-dimethoxyxanthone, 3,4-dihydroxy-2-methoxyxanthone, 1,3-dimethoxy- 5-hydroxyxanthone, 2,3-dimethoxy-4-hydroxyxantona, 3-hydroxy-2-methoxyxanthone and 2-hydroxy-1-methoxyxanthone and xantonolignoid kielcorin. Among the compounds isolated, the xatonolignoid keilcorine indicated activity when compared to the standard chloroquine. The assessment of potential trypanocidal was also a part of this work and among the isolated xanthones, 3,4-dihydroxy-2-methoxyxanthone showed to be the most active, especially against the resistant strain to benzonidazole (Bolivia strain). In hexane fraction of leaves from B. glaziovii was noted antichagasic potencial for this specie. The antioxidant test used in this study led to the isolation of several flavonoids with antioxidant activity: quercitrin, podocarpusflavone A and the mixture of quercetin-3-O-glucoside and quercetin-3-O-galactoside, showing the importance of catechol group for the potentiating of antioxidant activity. The bio-guided antimicrobial activity using six strains of methicillin-resistant Staphylococcus aureus resulted in the isolation of the prenylated phloroglucinol derivative (HGK-1), which proved to be responsible for the potent activity exhibited by the hexane extract of the branches of K. variabilis. The xanthones isolated were evaluated... (Complete abstract click electronic access below)
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Moura, Adriana Candido da Silva [UNESP]. « Uso sustentável da biodiversidade brasileira : avaliação químico-farmacológica de plantas superiores : Indigofera hirsuta (Fabaceae) ». Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/97958.
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As plantas medicinais utilizadas no tratamento de diversas doenças são fontes de uma infinidade de novas moléculas de interesse para a humanidade. Este trabalho investigou a composição química das partes aéreas do chá e do extrato metanólico de Indigofera hirsuta (Fabaceae), popularmente conhecida como “anileira” e encontrada no Cerrado brasileiro. O chá foi fracionado por cromatografia de permeação em gel e cromatografia líquida de média pressão, tendo-se isolado: kaempferol, ácido protocatecuico, kaempferol-3-O-β-D-glucopiranosideo, triptofano e uracila. O extrato metanólico foi fracionado por cromatografia líquida de alta pressão, que possibilitou o isolamento de: ácido gálico, galato de metila, rutina e kaempferol-3-O-β-D-glucopiranosideo. As substâncias foram identificadas por técnicas espectroscópicas (UV, IV e RMN) e as estruturas confirmadas pelo uso da técnica acoplada de HPLC-DAD-ESI-MS. O chá, extrato metanólico e as substâncias isoladas foram avaliados quanto à atividade antioxidante, utilizando-se DPPH. O extrato metanólico apresentou significativa atividade antioxidante, enquanto que o chá não apresentou atividade antioxidante considerável, quando comparados com o padrão ácido gálico. Das substâncias isoladas, o galato de metila apresentou a maior atividade antioxidante. O chá de I. hirsuta foi também avaliado quanto à atividade gastroprotetora em lesões induzida por etanol absoluto em 3 diferentes doses: 125 mg.Kg-1, 250 mg.Kg-1 e 500 mg.Kg-1, sendo a menor dose a que apresentou melhor efeito. Contudo, o chá de Indigofera hirsuta não apresentou atividade gastroprotetora
Medicinal plants used in the treatment of various diseases and are source of many new molecules. This work investigates the chemical composition of the aerial parts of the infusion and methanol extract of Indigofera hirsuta (Fabaceae), popularly known as “anileira” and found in the Brazilian Cerrado. The infusion was fractionated by gel permeation chromatography and medium pressure liquid chromatography, it was possible to isolate kaempferol, protocatecuic acid, kaempferol-3-O-β-D-glucopyranoside, tryptophan and uracil. The methanol extract was fractionated by high pressure liquid chromatography, which allowed the isolation of gallic acid, methyl gallate, rutin and kaempferol-3-O-β-D-glucopyranoside. The substances were identified by spectroscopic techniques (UV, IR and NMR) and confirmed by the use of HPLC-DAD-ESI-MS coupling. The infusion, methanol extract and isolated compounds were evaluated for their antioxidant activity using DPPH. The methanol extract showed significant antioxidant activity, while the tea did not show significant antioxidant activity, when compared to gallic acid. Among the isolated substances methyl gallate presented the highest antioxidant activity. The I. hirsuta was also evaluated for its gastroprotective activity in lesions induced by absolute ethanol in 3 different doses (125 mg.Kg-1, 250 mg.Kg-1 and 500 mg.Kg-1).The lowest dose showed the best effect. However, the infusion not active gastroprotective
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Coqueiro, Aline. « Fracionamento bioguiado para selação de substâncias antioxidante, antimalárica e antibiótica potenciais nas espécies Kielmeyera variabilis (Clusiaceae) e Brosimum Glaziovii (Moraceae) / ». Araraquara : [s.n.], 2010. http://hdl.handle.net/11449/105815.
Texte intégralRésumé :
Orientador: Vanderlan da Silva BolzaniBanca: Marcia Nasser Lopes
Banca: José Angelo Slveira Zuanazzi
Banca: Horácio Adolfo Heinzen Gozález
Resumo: Os testes biológicos realizados por pesquisadores colaboradores do NuBBE para as espécies selecionadas para este estudo Brosimum glaziovii e Kielmeyera variabilis indicaram K. variabilis como uma importante fonte de metabólitos especiais bioativos. O fracionamento bioguiado da fração AcOEt dos galhos de K. variabilis para isolamento de substâncias com potencial antimalárico foi realizado via teste químico com -hematina e in vitro com Plasmodium falciparum, levando a identificação das xantonas oxigenadas 3,6-diidroxi-1,4,8-trimetoxixantona, 3,5-diidroxi-4-metoxixantona, 3,4-diidroxi-6,8-dimetoxixantona, 3,4-diidroxi-2-metoxixantona, 5-hidroxi-1,3- dimetoxixantona, 2,3-dimetoxi-4-hidroxixantona, 3-hidroxi-2-metoxixantona e 2-hidroxi- 1-metoxi-xantona e o xantonolignóide kielcorina. Dentre as substâncias isoladas, o xatonolignóide kielcorina foi considerado ativo quando comparado ao padrão cloroquina. A avaliação do potencial tripanocida também foi realizada para as xantonas isoladas e dentre estas, a 3,4-diidroxi-2-metoxixantona foi a mais ativa, principalmente para a cepa resistente ao benzonidazol (cepa Bolívia). Na fração EHFB das folhas de B. glaziovii foi observado o potencial antichagásico desta espécie. Os resultados observados para os ensaios antioxidantes levaram ao isolamento dos flavonóides quercitrina, podocarpusflavona A e da mistura de quercetina-3-Oglicosídeo e quercetina-3-O-galactosídeo, evidenciando a importância dos grupos catecólicos na potencialização da ação antioxidante. O estudo bioguiado pela atividade antimicrobiana com seis cepas de Staphylococcus aureus resistentes à meticilina culminou no isolamento de um derivado prenilado do floroglucinol (HGK-1) o qual demonstrou ser responsável pela potente atividade demonstrada pela fração hexânica dos galhos de K. variabilis. As xantonas isoladas tiveram seu potencial antimicrobiano... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Several biological activities have been carried out by NuBBE's collaborators aiming the identification of active extracts from plant species, and Brosimum glaziovii and Kielmeyera variables showed to be important sources of bioactive secondary metabolites. Bio-guided fractionation of the EtOAc bioactive fraction of the branches of K. variabilis by using of the chemical test -hematin, and in vitro by using of Plasmodium falciparum, led to the isolation and identification of oxygenated xanthones 3,6-dihydroxy-1,4,8-trimethoxyxanthone, 3,5-dihydroxy-4-methoxyxanthone, 3,4- dihydroxy-6,8-dimethoxyxanthone, 3,4-dihydroxy-2-methoxyxanthone, 1,3-dimethoxy- 5-hydroxyxanthone, 2,3-dimethoxy-4-hydroxyxantona, 3-hydroxy-2-methoxyxanthone and 2-hydroxy-1-methoxyxanthone and xantonolignoid kielcorin. Among the compounds isolated, the xatonolignoid keilcorine indicated activity when compared to the standard chloroquine. The assessment of potential trypanocidal was also a part of this work and among the isolated xanthones, 3,4-dihydroxy-2-methoxyxanthone showed to be the most active, especially against the resistant strain to benzonidazole (Bolivia strain). In hexane fraction of leaves from B. glaziovii was noted antichagasic potencial for this specie. The antioxidant test used in this study led to the isolation of several flavonoids with antioxidant activity: quercitrin, podocarpusflavone A and the mixture of quercetin-3-O-glucoside and quercetin-3-O-galactoside, showing the importance of catechol group for the potentiating of antioxidant activity. The bio-guided antimicrobial activity using six strains of methicillin-resistant Staphylococcus aureus resulted in the isolation of the prenylated phloroglucinol derivative (HGK-1), which proved to be responsible for the potent activity exhibited by the hexane extract of the branches of K. variabilis. The xanthones isolated were evaluated... (Complete abstract click electronic access below)
Doutor
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Vasconcelos, Paulo César de Paula [UNESP]. « Efeito da (-)-epicatequina presente nas folhas Mouriri pusa Gardin. (Melastomataceae) na prevenção e tratamento de colite ulcerativa em ratos ». Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/91671.
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A etiologia da colite ulcerativa ainda permanece desconhecida, porém atinge uma grande parcela da população mundial. A maioria das terapias disponiveis tem eficácia limitada e geram significativos clínicos efeitos adversos. A especie medicinal Mouriri pusa Gardn. (Melastomataceae) foi citada diversas vezes pela população local do Tocantins como útil no tratamento de distúrbios do trato digestório. Os estudos preliminares com essa planta tem apresentado efeitos gastroprotetores e cicatrizantes intensos. Estudos fitoquimicos de seu extrato metanólico revelaram presença de (-)- epicatequina, além de outros flavonóides, e taninos. Nesse projeto, induziu-se colite ulcerativa em ratos per injeção local de acido trinitrobenzenosulfonico (TNBS). Foram analisados parametros morfológicos, inflamatórios, imunohistoquimicos e Western Blot. 0 efeito da (-)-epicatequina foi avaliado em modele agudo nas doses de 5,10,25 e 50 mg/kg (p.o). Os animais receberam os tratamentos uma vez por dia durante 3 dias antes da indução de colite, 2 h e 24 h após a mesma. Observou-se macroscopicamente que as doses de 10 e 50 mg/kg (EC10 e ECSO)de epicatequina foram efetivas em reduzir 0 grau de seriedade da lesão, sendo confirmado pela análise microscópica para EC10. Nas quantificações do tecido intestinal, observou-se que a concentração de glutationa em EC10 foi maior que no controle, mostrando um possivel mecanismo de ação, já que a manutenção da glutationa no tecido inflamado pode indicar potencial antioxidante da substância. Observou-se diminuição de COX-2, um parametro inflamatório, e um aumento de PCNA, antigeno de proliferação celular, em EC10, dicando ação antiinflamatória e estimuladora de proliferação celular. EC10 e EC50 foram usadas então para o modelo crônico de colite, no qual os diferentes grupos de animais receberam, após indução de colite no primeiro dia...
Ulcerative colitis etiology is still not completely known, however, it is present among great portion of world's population. The majority of available therapies has limited efficacy and provides significant adverse effects. The medicinal species Mouriri pusa Gardn. (Melastomataceae) has been often mentioned by local population from Tocantins as useful in the treatment of gastrointestinal disorders. Previous studies with this plant have presented intense gastroprotective and cicatrizing effects. Phyochemical studies of its methanolic extract revealed presence of (-)-epicatechin, besides other flavonoids, and tannins, In this work, ulcerative colitis was induced in rats by local injection of TNBS (Trinitrobenzenesulphonic acid). We analyzed morphological, inflammatory, immunohistochemical and Western Blot parameters. (-)- Epicatechin effect was evaluated in acute model in 5, 10, 25 e 5Omg/kg doses (p.o). The animals received treatments once a day for 3 days before colitis induction, and 2 h and 24 h after it. The doses of 10 and 5Omg/kg (EC10 and EC5O) were macroscopically observed to be effective in reducing lesion seriousness, what was confirmed by microscopical analysis for EC10. By quantifications in the colon tissue, it was observed that glutathion concentration in EC10 was greater than in control, showing a possible echanism of action, since glutathione maintenance in the inflamed tissue may . dicate antioxidant potential from the compound. It was observed COX-2 reduction, an inflammatory parameter, and an increase in PCNA, proliferating cell antigen, in EClO, indicating anti-inflammatory and proliferation stimulating action. EC10 and EC were then used for chronic colitis model, in which the groups, after colitis induction in the first Day, treatments for 21 days. At the end of each week, some of the rats from each group were killed for accompaniment, and after the second week ... (Complete abstract click electronic access below)
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Arantes, Glenda Marqueti. « Bioprospecção em espécies do gênero Sclerolobium sp : busca de agentes quimiopreventivos / ». Araraquara [s.n.], 2011. http://hdl.handle.net/11449/105818.
Texte intégralRésumé :
Orientador: Dulce Helena Siqueira SilvaBanca: Ana Marisa Fusco Almeida
Banca: Wilson Roberto da Cunha
Banca: Niege Araçari Jacometti Cardoso Furtado
Banca: Ana Luisa Lacava Lordello
Resumo: A família Fabaceae é subdividida em 3 subfamílias: Faboideae, Caesalpinoideae e Mimosoideae, que englobam mais de 700 gêneros e 18000 espécies, bem distribuídas nas regiões tropicais e subtropicais. Inclui espécies de alta relevância econômica, como a soja, feijão, cerejeira, angelim e sucupira, além do pau-brasil, de importância histórica para o Brasil. Neste trabalho, os extratos etanólicos das folhas de Sclerolobium aureum, S. denudatum e S. paniculatum mostraram forte potencial antioxidante, sendo selecionados para investigação fitoquímica detalhada. O fracionamento cromatográfico destes extratos evidenciou sua composição química, destacando-se a presença de esqualeno, tocoferóis e lupenona, identificados por CG-EM, predominantes nas frações de baixa polaridade. O extrato hidroalcoólico de S. aureum foi submetido a etapas de purificação, incluindo o uso de CLAE-UV-DAD, evidenciando a presença majoritária de ácido gálico, flavonoides monoglicosilados e catequina, identificados por RMN, EM e UV. Os extratos hidroalcoólicos de S. denudatum e S. paniculatum foram submetidos a partição líquido-líquido e as frações resultantes foram analisadas por CLAE-UV-DAD e CLAE-EM-EM para identificação dos seus constituintes por desreplicação, ou seja, evitando-se procedimentos de purificação de substâncias conhecidas. Esta estratégia permitiu conhecer os metabólitos secundários das três espécies, que apresentaram perfis químicos semelhantes com a predominância de flavonoides monoglicosilados. As frações semipurificadas e substâncias isoladas mostraram elevado potencial de sequestro de radicais livres frente ao DPPH, destacando-se a presença de antioxidantes lipofílicos e hidrofílicos, atrativa para aplicações em cosméticos. Adicionalmente, foi observado potencial imunomodulador... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Fabaceae family comprises 3 subfamilies: Faboideae, Caesalpinoideae and Mimosoideae, with more than 700 genera and 18000 species, widespread in tropical and subtropical regions. It includes economically important species as soybean, beans, angelim, sucupira, in addition to pau-brasil (Caesalpinea echinata), which has historical importance in Brazil for its wood pigments. In this work, ethanol extracts of Sclerolobium aureum, S. denudatum and S. paniculatum leaves were investigated and showed strong antioxidant potential, and were selected for further investigation. Their chromatographic fractionation evidenced the presence of squalene, tocopherols and lupenone as major compounds in low polarity fractions, by GC-MS analysis. The hydroalcoholic extract of S. aureum was submitted to purification procedures, including the use of HPLC-UV-DAD, which evidenced gallic acid, flavonoid monoglucosides and catechin as major compounds, identified mainly by NMR, MS and UV techniques. HPLC-UV-DAD and LC-MS-MS analysis were further carried out on the hydroalcoholic extract of S. denudatum and S. paniculatum, leading to the identification of their major constituents by dereplication, avoiding the purification of known compounds. Such strategy evidenced a similar chemical profile for the three Sclerolobium species, with flavonoid monoglucosides as major compounds. Strong free radical scavenging potential was observed for the fractions and isolated compounds towards DPPH, evidencing the presence of lipophilic and hydrophilic antioxidants, which might be important for cosmetics development. In addition, the immunomodulatory potential of the hexane and ethyl acetate fractions from S. denudatum were evidenced through the dose-dependent inhibition of nitrite release by pre-treated macrophages, which might... (Complete abstract click electronic access below)
Doutor
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Pacífico, Mariana [UNESP]. « Estudo químico e atividades mutagênica e antiulcerogênica de Syngonanthus nitens (Bong.) Ruhland ». Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/97968.
Texte intégralRésumé :
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pacifico_m_me_araiq.pdf: 2236127 bytes, checksum: bccb79d8bad77e2a42b5b5e4552f4b01 (MD5)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Neste trabalho, foi investigada a composição química de Syngonanthus nitens (Bong.) Ruhland, espécie pertencente à família Eriocaulaceae, conhecida popularmente como “capim dourado” e amplamente utilizada para o artesanato, sendo de grande importância econômica principalmente para populações do Tocantins e Minas Gerais. Espécies dessa família são conhecidas popularmente como “sempre-vivas” e a maioria delas ocorre em Campos Rupestres do Brasil. Foram preparados extratos de capítulos e de escapos, separadamente, por maceração utilizando hexano e diclorometano e por percolação com metanol. Os extratos metanólicos foram fracionados por colunas de permeação em gel, cromatografia líquida de média pressão (MPLC), cromatografia líquida de alta eficiência, com detector de arranjo de diodo (HPLC-DAD) e com detector de índice de refração (HPLC-RI) e cromatografia em contracorrente (HSCCC). As estruturas foram caracterizadas por espectroscopia na região do ultravioleta, técnicas mono e bidimensionais de RMN e por espectrometria de massas com fonte electrospray e analisador íon trap (modo de inserção direta). Foram isoladas as substâncias: 1,3,6-triidroxi-2-metoxixantona; 1,3,6-triidroxi-2,5-dimetoxixantona; 1,5,7-triidroxi-3,6-dimetoxixantona; 1,3,6,8-tetraidroxi-2,5-dimetoxixantona; 1,3,6,8-tetraidroxi-5-metoxixantona; 7-metoxiluteolina-6-C-β-D-glicopiranosideo, 7-metoxiluteolina-8-C-β-D-glicopiranosideo, 3`,7-dimetoxiluteolina-6-C-β-D-glicopiranosideo, 6-hidroxiluteolina e luteolina. Os extratos metanólicos de capítulos e escapos de S. nitens foram avaliados quanto à atividade antiulcerogênica e mutagênica. Através do modelo de lesão ulcerativa induzida por etanol absoluto, verificou-se que os dois extratos apresentaram atividade gastroprotetora. Na dose de 500 mg kg-1 do extrato de...
In this work, the chemical composition of Syngonanthus nitens (Bong.) Ruhland was investigated. This plant belongs to Eriocaulaceae family, popularly known as “capim dourado” and widely used to make baskets and other handcraft products. It´s a very important economical specie to local communities in Tocantins ans Minas Gerais states, mainly. Plants of this family are known as “everlasting flower” and they can be found in “Campos Rupestres” vegetation in Brazil. Scapes and capitulae were extracted, sequentially, with hexane, dichloromethane and methanol. Methanol extract were fractionated by several chromatographic techniques, including gel permeation chromatography, Medium Pressure Liquid Chromatography (MPLC), High Pressure Liquid Chromatography (HPLC-DAD and HPLC-RI), High Speed Countercurrent Chromatography (HSCCC). Structures were determined by ultraviolet spectroscopy, as well as mono and bidimensional NMR techniques, besides electrospray – ion trap – mass spectrometry. The chemical study of S. nitens led to the identification of five xanthones: 1,3,6-trihydroxy-2-methoxyxanthone; 1,3,6- trihydroxy-2,5-dimethoxyxanthone; 1,5,7- trihydroxy -3,6-dimethoxyxanthone; 1,3,6,8-tetrahydroxy-2,5- dimethoxyxanthone e 1,3,6,8-tetrahyidroxyi-5-methoxyxanthone, and five flavones: 7-methoxyluteolin-6-C-β-D-glucopyranoside; 7-methoxyluteolin-8-C-β-D-glucopyranoside; 4`,7-dimethoxyluteolin-6-C-β-D-glucopyranoside; 6-hydroxyluteolin and luteolin. Pharmacological assays demonstrated that the methanol extract of capitulae and scape from S. nitens has presented gastroprotective activity in the ethanol induced ulcer model. According the results of Ames test, the mutagenicity was considered negative for all tested concentrations of the three methanol extracts, at all tested strains. The chemical data obtained in this work also added more data to the discussion of the taxonomy of Eriocaulaceae
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Pacífico, Mariana. « Estudo químico e atividades mutagênica e antiulcerogênica de Syngonanthus nitens (Bong.) Ruhland / ». Araraquara : [s.n.], 2010. http://hdl.handle.net/11449/97968.
Texte intégralRésumé :
Orientador: Lourdes Campaner dos SantosBanca: Lucienir Pains Duarte
Banca: Sidney Augusto Vieira Filho
Resumo: Neste trabalho, foi investigada a composição química de Syngonanthus nitens (Bong.) Ruhland, espécie pertencente à família Eriocaulaceae, conhecida popularmente como "capim dourado" e amplamente utilizada para o artesanato, sendo de grande importância econômica principalmente para populações do Tocantins e Minas Gerais. Espécies dessa família são conhecidas popularmente como "sempre-vivas" e a maioria delas ocorre em Campos Rupestres do Brasil. Foram preparados extratos de capítulos e de escapos, separadamente, por maceração utilizando hexano e diclorometano e por percolação com metanol. Os extratos metanólicos foram fracionados por colunas de permeação em gel, cromatografia líquida de média pressão (MPLC), cromatografia líquida de alta eficiência, com detector de arranjo de diodo (HPLC-DAD) e com detector de índice de refração (HPLC-RI) e cromatografia em contracorrente (HSCCC). As estruturas foram caracterizadas por espectroscopia na região do ultravioleta, técnicas mono e bidimensionais de RMN e por espectrometria de massas com fonte electrospray e analisador íon trap (modo de inserção direta). Foram isoladas as substâncias: 1,3,6-triidroxi-2-metoxixantona; 1,3,6-triidroxi-2,5-dimetoxixantona; 1,5,7-triidroxi-3,6-dimetoxixantona; 1,3,6,8-tetraidroxi-2,5-dimetoxixantona; 1,3,6,8-tetraidroxi-5-metoxixantona; 7-metoxiluteolina-6-C-β-D-glicopiranosideo, 7-metoxiluteolina-8-C-β-D-glicopiranosideo, 3',7-dimetoxiluteolina-6-C-β-D-glicopiranosideo, 6-hidroxiluteolina e luteolina. Os extratos metanólicos de capítulos e escapos de S. nitens foram avaliados quanto à atividade antiulcerogênica e mutagênica. Através do modelo de lesão ulcerativa induzida por etanol absoluto, verificou-se que os dois extratos apresentaram atividade gastroprotetora. Na dose de 500 mg kg-1 do extrato de... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: In this work, the chemical composition of Syngonanthus nitens (Bong.) Ruhland was investigated. This plant belongs to Eriocaulaceae family, popularly known as "capim dourado" and widely used to make baskets and other handcraft products. It's a very important economical specie to local communities in Tocantins ans Minas Gerais states, mainly. Plants of this family are known as "everlasting flower" and they can be found in "Campos Rupestres" vegetation in Brazil. Scapes and capitulae were extracted, sequentially, with hexane, dichloromethane and methanol. Methanol extract were fractionated by several chromatographic techniques, including gel permeation chromatography, Medium Pressure Liquid Chromatography (MPLC), High Pressure Liquid Chromatography (HPLC-DAD and HPLC-RI), High Speed Countercurrent Chromatography (HSCCC). Structures were determined by ultraviolet spectroscopy, as well as mono and bidimensional NMR techniques, besides electrospray - ion trap - mass spectrometry. The chemical study of S. nitens led to the identification of five xanthones: 1,3,6-trihydroxy-2-methoxyxanthone; 1,3,6- trihydroxy-2,5-dimethoxyxanthone; 1,5,7- trihydroxy -3,6-dimethoxyxanthone; 1,3,6,8-tetrahydroxy-2,5- dimethoxyxanthone e 1,3,6,8-tetrahyidroxyi-5-methoxyxanthone, and five flavones: 7-methoxyluteolin-6-C-β-D-glucopyranoside; 7-methoxyluteolin-8-C-β-D-glucopyranoside; 4',7-dimethoxyluteolin-6-C-β-D-glucopyranoside; 6-hydroxyluteolin and luteolin. Pharmacological assays demonstrated that the methanol extract of capitulae and scape from S. nitens has presented gastroprotective activity in the ethanol induced ulcer model. According the results of Ames test, the mutagenicity was considered negative for all tested concentrations of the three methanol extracts, at all tested strains. The chemical data obtained in this work also added more data to the discussion of the taxonomy of Eriocaulaceae
Mestre
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Andreo, Marcio Adriano [UNESP]. « Prospecção químico-farmacológica em plantas superiores : estudo químico e atividade sobre o sistema gastrintestinal de Mouriri pusa Gardner e Mouriri elliptica Martius (Melastomataceae) ». Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/105842.
Texte intégralRésumé :
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andreo_ma_dr_araiq_prot.pdf: 19440351 bytes, checksum: 9a842fbeed3bcf8ca3fae9b5fb5920d4 (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Neste trabalho foram estudadas folhas de Mouriri pusa Gardner e Mouriri elliptica Martius, pertencentes à família Melastomataceae. Espécies de Mouriri são utilizadas popularmente para problemas gastrointestinais, tais como úlceras. O estudo químico do extrato metanólico das folhas de M. pusa permitiu a identificação de uma flavona, dezessete flavonóis e dois flavan-3-óis, além de constatar a presença de taninos e saponinas. O estudo químico do extrato metanólico das folhas de M. elliptica permitiu a identificação de uma flavanona, dez flavonóis, dois falvan-3-óis e oito triterpenos pentacíclicos, além de constatar a presença de taninos e derivados de ácido ellágico.
In this work was studied the leaves of Mouriri pusa Gardner and Mouriri elliptica Martius, belonging to the Melastomataceae family. Species of Mouriri are popularly used against gastrointestinal problems, such as ulcers. THe chemical study of the methanol extract from the leaves of M. pusa allowed the identification of one flavone, seventeen flavonols and two falvan-e-ols (besides the detection of tannins and saponins), where as the chemical study fo the methanol extract from the leaves of M. elliptica led to the identification of one flavanone, ten flavonols, two flavan-3-ols and eight pentacyclic triterpenes (besides tannins and acid ellagic derivates)... (Complete abstract click electronic access below)
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Moura, Adriana Candido da Silva. « Uso sustentável da biodiversidade brasileira : avaliação químico-farmacológica de plantas superiores : Indigofera hirsuta (Fabaceae) / ». Araraquara : [s.n.], 2010. http://hdl.handle.net/11449/97958.
Texte intégralRésumé :
Orientador: Lourdes Campaner dos SantosBanca: Wagner Vilegas
Banca: Ângela Regina Araujo
Banca: Luiz Alberto Beraldo de Moraes
Resumo: As plantas medicinais utilizadas no tratamento de diversas doenças são fontes de uma infinidade de novas moléculas de interesse para a humanidade. Este trabalho investigou a composição química das partes aéreas do chá e do extrato metanólico de Indigofera hirsuta (Fabaceae), popularmente conhecida como "anileira" e encontrada no Cerrado brasileiro. O chá foi fracionado por cromatografia de permeação em gel e cromatografia líquida de média pressão, tendo-se isolado: kaempferol, ácido protocatecuico, kaempferol-3-O-β-D-glucopiranosideo, triptofano e uracila. O extrato metanólico foi fracionado por cromatografia líquida de alta pressão, que possibilitou o isolamento de: ácido gálico, galato de metila, rutina e kaempferol-3-O-β-D-glucopiranosideo. As substâncias foram identificadas por técnicas espectroscópicas (UV, IV e RMN) e as estruturas confirmadas pelo uso da técnica acoplada de HPLC-DAD-ESI-MS. O chá, extrato metanólico e as substâncias isoladas foram avaliados quanto à atividade antioxidante, utilizando-se DPPH. O extrato metanólico apresentou significativa atividade antioxidante, enquanto que o chá não apresentou atividade antioxidante considerável, quando comparados com o padrão ácido gálico. Das substâncias isoladas, o galato de metila apresentou a maior atividade antioxidante. O chá de I. hirsuta foi também avaliado quanto à atividade gastroprotetora em lesões induzida por etanol absoluto em 3 diferentes doses: 125 mg.Kg-1, 250 mg.Kg-1 e 500 mg.Kg-1, sendo a menor dose a que apresentou melhor efeito. Contudo, o chá de Indigofera hirsuta não apresentou atividade gastroprotetora
Abstract: Medicinal plants used in the treatment of various diseases and are source of many new molecules. This work investigates the chemical composition of the aerial parts of the infusion and methanol extract of Indigofera hirsuta (Fabaceae), popularly known as "anileira" and found in the Brazilian Cerrado. The infusion was fractionated by gel permeation chromatography and medium pressure liquid chromatography, it was possible to isolate kaempferol, protocatecuic acid, kaempferol-3-O-β-D-glucopyranoside, tryptophan and uracil. The methanol extract was fractionated by high pressure liquid chromatography, which allowed the isolation of gallic acid, methyl gallate, rutin and kaempferol-3-O-β-D-glucopyranoside. The substances were identified by spectroscopic techniques (UV, IR and NMR) and confirmed by the use of HPLC-DAD-ESI-MS coupling. The infusion, methanol extract and isolated compounds were evaluated for their antioxidant activity using DPPH. The methanol extract showed significant antioxidant activity, while the tea did not show significant antioxidant activity, when compared to gallic acid. Among the isolated substances methyl gallate presented the highest antioxidant activity. The I. hirsuta was also evaluated for its gastroprotective activity in lesions induced by absolute ethanol in 3 different doses (125 mg.Kg-1, 250 mg.Kg-1 and 500 mg.Kg-1).The lowest dose showed the best effect. However, the infusion not active gastroprotective
Mestre
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Andreo, Marcio Adriano. « Prospecção químico-farmacológica em plantas superiores : estudo químico e atividade sobre o sistema gastrintestinal de Mouriri pusa Gardner e Mouriri elliptica Martius (Melastomataceae) / ». Araraquara : [s.n.], 2008. http://hdl.handle.net/11449/105842.
Texte intégralRésumé :
Orientador: Wagner VilegasBanca: Isabele Rodrigues Nascimento
Banca: Norberto Peporine Lopes
Banca: Elfriede Marianne Bacchi
Banca: Daisy Maria Fávero Salvadori
Resumo: Neste trabalho foram estudadas folhas de Mouriri pusa Gardner e Mouriri elliptica Martius, pertencentes à família Melastomataceae. Espécies de Mouriri são utilizadas popularmente para problemas gastrointestinais, tais como úlceras. O estudo químico do extrato metanólico das folhas de M. pusa permitiu a identificação de uma flavona, dezessete flavonóis e dois flavan-3-óis, além de constatar a presença de taninos e saponinas. O estudo químico do extrato metanólico das folhas de M. elliptica permitiu a identificação de uma flavanona, dez flavonóis, dois falvan-3-óis e oito triterpenos pentacíclicos, além de constatar a presença de taninos e derivados de ácido ellágico. (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: In this work was studied the leaves of Mouriri pusa Gardner and Mouriri elliptica Martius, belonging to the Melastomataceae family. Species of Mouriri are popularly used against gastrointestinal problems, such as ulcers. THe chemical study of the methanol extract from the leaves of M. pusa allowed the identification of one flavone, seventeen flavonols and two falvan-e-ols (besides the detection of tannins and saponins), where as the chemical study fo the methanol extract from the leaves of M. elliptica led to the identification of one flavanone, ten flavonols, two flavan-3-ols and eight pentacyclic triterpenes (besides tannins and acid ellagic derivates)... (Complete abstract click electronic access below)
Doutor
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Junior, João Francisco Lucon. « Estudo da atividade inibitória de extratos vegetais, flavonoides e derivados do ácido cafeico sobre a enzima arginase de Leishmania (Leishmania) amazonensis ». Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/74/74135/tde-22092016-094420/.
Texte intégralRésumé :
Causada por protozoários do gênero Leishmania, a leishmaniose é uma doença infecciosa que afeta milhões de pessoas em todos os continentes. São grandes os desafios no tratamento da leishmaniose porque os fármacos atualmente disponíveis apresentam alta toxicidade, efeitos colaterais, alto custo e resistência parasitária. Sendo assim, faz-se necessário o desenvolvimento de novas drogas para o tratamento da doença de maneira mais eficiente. A investigação de novas alternativas terapêuticas, novos alvos bioquímicos, em particular a arginase em de Leishmania (L) amazonensis, é considerada um alvo interessante na busca de novos compostos leishmanicidas. A via bioquímica em que está envolvida a arginase é fundamental para a manutenção do ciclo de vida do parasito, sendo responsável pela hidrólise de L-arginina em L-ornitina em mamíferos. Muitos compostos oriundos de produtos naturais tem sido relatados como inibidores da arginase de L. (L.) amazonensis e a presença de grupos hidroxila em suas estruturas mostraram ser importantes na atividade inibidora da enzima. O objetivo desse trabaho estudar a interação bioquímica entre a enzima arginase de L. (L.) amazonensis, extratos vegetais, flavonoides e derivados do ácido cafeico. O extrato acetônico de folhas de Qualea grandiflora apresentou maior capacidade inibitória da arginase (IC50 = 1,7 ± 01 µg/mL) dentre os extratos analisados. Dentre os flavonoides, o composto mais potente foi a taxifolina (IC50 = 1,7 ± 0,2 µM). O verbascosídeo foi o derivado do ácido cafeico com maior potencial de inibição da arginase (IC50 = 0,5 ± 0,2 µM). As estruturas desses compostos podem servir como referência no desenvolvimento de novas drogas para o controle da leishmaniose, que tenham como alvo a arginase.Caused by protozoa of the genus Leishmania, leishmaniosis is an infectious disease that affects millions of people on all continents. The currently available drugs are highly toxic, expensive, have side effects and parasitic resistance and for these reasons there is a need of developing new drugs to more effective treatment of the disease. The research of new therapeutic alternatives, new biochemical targets, in particular the arginase of Leishmania (Leishmania) amazonensis is considered an interesting target in the search for new compounds leishmanicidal. The biochemistry of arginase pathway is essential for the survival of the parasite, is also responsible for hydrolysis of L- arginine to L- ornithine in mammals. Many compounds from natural products has been reported as inhibitors of arginase L. (L.) amazonensis, and the presence of hydroxyl groups in their structures shown to be important for inhibitory activity of the enzyme. This work studies the biochemical interaction between the arginase enzyme, plant extracts, flavonoids and derivatives of caffeic acid. The acetone extract of Qualea grandiflora leaves showed higher inhibitory capacity of arginase (IC50 = 1.7 ± 01 µg/mL) from the analyzed extracts. Among the flavonoids, the most potent compound was taxifolin (IC50 = 1.7 ± 0.2 µM). The verbascosideo was the derivative of caffeic acid with greater potential for arginase inhibition (IC50 = 0.5 ± 0.2 µM) The structures of these compounds can serve as a reference in developing new drugs for the control of leishmaniosis, which target arginase.
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Rodrigues, Juliana [UNESP]. « Uso sustentável da biodiversidade brasileira : prospecção químico-farmacológica em plantas superiores : metodologia para estabelecimento de perfis quali e quantitativos para extratos vegetais ». Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/105320.
Texte intégralRésumé :
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rodrigues_j_dr_araiq.pdf: 2215400 bytes, checksum: 0fd02af147bd646153b8c1d9da06c642 (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O objetivo desse trabalho foi a investigação da composição química de plantas do Cerrado, aplicando técnicas que permitam uma análise quali e quantitativa rápida e eficaz. As espécies estudadas neste projeto foram Miconia rubiginosa e Miconia stenostachya, pertencentes à família Melastomataceae. As espécies foram coletadas no Estado de São Paulo e os infusos foram preparados e particionados com acetato de etila e água. A fração acetato de etila da M. rubiginosa foi fracionada por Cromatografia em Contracorrente de Alta Velocidade (HSCCC), sendo isolados os compostos (-)-(2R,3R)-epicatequina (Mr1), casuarictina (Mr2), canferol-3-O-β-galactopiranosídeo (Mr3) e schizandrisídeo (Mr4). A fração acetato de etila da M. stenostachya foi fracionada por cromatografia de permeação em gel utilizando Sephadex LH-20, que possibilitou o isolamento da (+)-(2R,3S)-4’-O-metilgalocatequina (Ms1), (-)-(2R,3R)-4’-O-metilepigalocatequina (Ms2), miricetina-3-O-α-rhamnopiranosídeo (Ms3) e (-)-(2R,3R)-epicatequina (Ms4). Foram desenvolvidos métodos de separação dos enantiômeros da naringenina e catequinas por Cromatografia Líquida de Alta Eficiência acoplada a detectores de Dicroísmo Circular e Arranjo de Diodos (HPLC-CD-DAD). Os métodos desenvolvidos forneceram separação adequada com boa resolução. Foram obtidos os espectros de dicroísmo circular (CD) de todas as substâncias isoladas, permitindo a identificação dos enantiômeros. Uma metodologia de clean-up foi desenvolvida para a preparação de amostras para análise por cromatografia quiral. O método que utiliza cartucho de C18 (STRATA Phenomenex®) foi o que apresentou melhor seletividade. O método desenvolvido no HPLC-CD-DAD permitiu identificar a (-)-(2R,3R)-epicatequina no infuso de M. rubiginosa. O mesmo método foi aplicado para investigar a espécie Maytenus obtusifolia...
The objective of this project was to investigate the chemical composition of Cerrado plants, using techniques that allow a quick and efficient qualitative and quantitative analysis. In this project we studied the species Miconia rubiginosa and Miconia stenostachya which belong to the Melastomataceae family. Miconia species were collected at São Paulo State and water infusions were prepared and partitioned with EtOAc and water. The ethyl acetate fraction of M. rubiginosa was fractioned by High Speed Countercurrent Chromatography (HSCCC), and afforded (-)-(2R,3R)-epicatechin (Mr1), casuarictin (Mr2), kaempferol-3-O-β-galactopyranoside (Mr3), and schizandriside (Mr4). The ethyl acetate fraction of M. stenostachya was submitted to gel permeation chromatography over Sephadex LH-20, that led to the isolation of (+)-(2R,3S)-4'-O-methylgallocatechin (Ms1), (-)-(2R,3R)-4'-O-methylepigallocatechin (Ms2), myricetin-3-O-α-rhamnopyranoside (Ms3), and (-)-(2R,3R)-epicatechin (Ms4). Methods were developed for the enantiomeric separation of naringenin and catechins by High Performance Liquid Chromatography with Circular Dichroism and Diode Array Detectors (HPLC-CD-DAD). The developed methods provided good separation and resolution. CD spectra of all these substances were obtained, allowing the identification of the enantiomers. A clean-up methodology was developed for the preparation of plant samples previous to the chiral HPLC analysis. The method using C18-cartridge (Phenomenex STRATA®) showed the best selectivity. The method developed using HPLC-CD-DAD allowed to identify (-)-(2R,3R)-epicatechin in the infusion of M. rubiginosa. The same method was applied to investigate the commonly used... (Complete abstract click electronic access below)
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Vasconcelos, Paulo César de Paula. « Efeito da (-)-epicatequina presente nas folhas Mouriri pusa Gardin. (Melastomataceae) na prevenção e tratamento de colite ulcerativa em ratos / ». Botucatu : [s.n.], 2009. http://hdl.handle.net/11449/91671.
Texte intégralRésumé :
Resumo: A etiologia da colite ulcerativa ainda permanece desconhecida, porém atinge uma grande parcela da população mundial. A maioria das terapias disponiveis tem eficácia limitada e geram significativos clínicos efeitos adversos. A especie medicinal Mouriri pusa Gardn. (Melastomataceae) foi citada diversas vezes pela população local do Tocantins como útil no tratamento de distúrbios do trato digestório. Os estudos preliminares com essa planta tem apresentado efeitos gastroprotetores e cicatrizantes intensos. Estudos fitoquimicos de seu extrato metanólico revelaram presença de (-)- epicatequina, além de outros flavonóides, e taninos. Nesse projeto, induziu-se colite ulcerativa em ratos per injeção local de acido trinitrobenzenosulfonico (TNBS). Foram analisados parametros morfológicos, inflamatórios, imunohistoquimicos e Western Blot. 0 efeito da (-)-epicatequina foi avaliado em modele agudo nas doses de 5,10,25 e 50 mg/kg (p.o). Os animais receberam os tratamentos uma vez por dia durante 3 dias antes da indução de colite, 2 h e 24 h após a mesma. Observou-se macroscopicamente que as doses de 10 e 50 mg/kg (EC10 e ECSO)de epicatequina foram efetivas em reduzir 0 grau de seriedade da lesão, sendo confirmado pela análise microscópica para EC10. Nas quantificações do tecido intestinal, observou-se que a concentração de glutationa em EC10 foi maior que no controle, mostrando um possivel mecanismo de ação, já que a manutenção da glutationa no tecido inflamado pode indicar potencial antioxidante da substância. Observou-se diminuição de COX-2, um parametro inflamatório, e um aumento de PCNA, antigeno de proliferação celular, em EC10, dicando ação antiinflamatória e estimuladora de proliferação celular. EC10 e EC50 foram usadas então para o modelo crônico de colite, no qual os diferentes grupos de animais receberam, após indução de colite no primeiro dia ... (Resumo completo, clicar acesso eletrônico abaixo)Abstract: Ulcerative colitis etiology is still not completely known, however, it is present among great portion of world's population. The majority of available therapies has limited efficacy and provides significant adverse effects. The medicinal species Mouriri pusa Gardn. (Melastomataceae) has been often mentioned by local population from Tocantins as useful in the treatment of gastrointestinal disorders. Previous studies with this plant have presented intense gastroprotective and cicatrizing effects. Phyochemical studies of its methanolic extract revealed presence of (-)-epicatechin, besides other flavonoids, and tannins, In this work, ulcerative colitis was induced in rats by local injection of TNBS (Trinitrobenzenesulphonic acid). We analyzed morphological, inflammatory, immunohistochemical and Western Blot parameters. (-)- Epicatechin effect was evaluated in acute model in 5, 10, 25 e 5Omg/kg doses (p.o). The animals received treatments once a day for 3 days before colitis induction, and 2 h and 24 h after it. The doses of 10 and 5Omg/kg (EC10 and EC5O) were macroscopically observed to be effective in reducing lesion seriousness, what was confirmed by microscopical analysis for EC10. By quantifications in the colon tissue, it was observed that glutathion concentration in EC10 was greater than in control, showing a possible echanism of action, since glutathione maintenance in the inflamed tissue may . dicate antioxidant potential from the compound. It was observed COX-2 reduction, an inflammatory parameter, and an increase in PCNA, proliferating cell antigen, in EClO, indicating anti-inflammatory and proliferation stimulating action. EC10 and EC were then used for chronic colitis model, in which the groups, after colitis induction in the first Day, treatments for 21 days. At the end of each week, some of the rats from each group were killed for accompaniment, and after the second week ... (Complete abstract click electronic access below)
Orientador: Cláudia Helena Pellizzon
Coorientador: Clélia Akiko Hiruma-Lima
Banca: Luís Cláudio Di Stasi
Banca: João Carlos Palazzo de Mello
Mestre
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Rodrigues, Juliana. « Uso sustentável da biodiversidade brasileira : prospecção químico-farmacológica em plantas superiores : metodologia para estabelecimento de perfis quali e quantitativos para extratos vegetais / ». Araraquara [s.n.], 2011. http://hdl.handle.net/11449/105320.
Texte intégralRésumé :
Orientador: Wagner VilegasCoorientador: Lourdes Campaner dos Santos
Banca: Isabele Rodrigues Nascimento
Banca: Vera Lucia Garcia Rehder
Banca: João Carlos Palazzo de Mello
Banca: José Arimatéia Dantas Lopes
Resumo: O objetivo desse trabalho foi a investigação da composição química de plantas do Cerrado, aplicando técnicas que permitam uma análise quali e quantitativa rápida e eficaz. As espécies estudadas neste projeto foram Miconia rubiginosa e Miconia stenostachya, pertencentes à família Melastomataceae. As espécies foram coletadas no Estado de São Paulo e os infusos foram preparados e particionados com acetato de etila e água. A fração acetato de etila da M. rubiginosa foi fracionada por Cromatografia em Contracorrente de Alta Velocidade (HSCCC), sendo isolados os compostos (-)-(2R,3R)-epicatequina (Mr1), casuarictina (Mr2), canferol-3-O-β-galactopiranosídeo (Mr3) e schizandrisídeo (Mr4). A fração acetato de etila da M. stenostachya foi fracionada por cromatografia de permeação em gel utilizando Sephadex LH-20, que possibilitou o isolamento da (+)-(2R,3S)-4'-O-metilgalocatequina (Ms1), (-)-(2R,3R)-4'-O-metilepigalocatequina (Ms2), miricetina-3-O-α-rhamnopiranosídeo (Ms3) e (-)-(2R,3R)-epicatequina (Ms4). Foram desenvolvidos métodos de separação dos enantiômeros da naringenina e catequinas por Cromatografia Líquida de Alta Eficiência acoplada a detectores de Dicroísmo Circular e Arranjo de Diodos (HPLC-CD-DAD). Os métodos desenvolvidos forneceram separação adequada com boa resolução. Foram obtidos os espectros de dicroísmo circular (CD) de todas as substâncias isoladas, permitindo a identificação dos enantiômeros. Uma metodologia de clean-up foi desenvolvida para a preparação de amostras para análise por cromatografia quiral. O método que utiliza cartucho de C18 (STRATA Phenomenex®) foi o que apresentou melhor seletividade. O método desenvolvido no HPLC-CD-DAD permitiu identificar a (-)-(2R,3R)-epicatequina no infuso de M. rubiginosa. O mesmo método foi aplicado para investigar a espécie Maytenus obtusifolia... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The objective of this project was to investigate the chemical composition of Cerrado plants, using techniques that allow a quick and efficient qualitative and quantitative analysis. In this project we studied the species Miconia rubiginosa and Miconia stenostachya which belong to the Melastomataceae family. Miconia species were collected at São Paulo State and water infusions were prepared and partitioned with EtOAc and water. The ethyl acetate fraction of M. rubiginosa was fractioned by High Speed Countercurrent Chromatography (HSCCC), and afforded (-)-(2R,3R)-epicatechin (Mr1), casuarictin (Mr2), kaempferol-3-O-β-galactopyranoside (Mr3), and schizandriside (Mr4). The ethyl acetate fraction of M. stenostachya was submitted to gel permeation chromatography over Sephadex LH-20, that led to the isolation of (+)-(2R,3S)-4'-O-methylgallocatechin (Ms1), (-)-(2R,3R)-4'-O-methylepigallocatechin (Ms2), myricetin-3-O-α-rhamnopyranoside (Ms3), and (-)-(2R,3R)-epicatechin (Ms4). Methods were developed for the enantiomeric separation of naringenin and catechins by High Performance Liquid Chromatography with Circular Dichroism and Diode Array Detectors (HPLC-CD-DAD). The developed methods provided good separation and resolution. CD spectra of all these substances were obtained, allowing the identification of the enantiomers. A clean-up methodology was developed for the preparation of plant samples previous to the chiral HPLC analysis. The method using C18-cartridge (Phenomenex STRATA®) showed the best selectivity. The method developed using HPLC-CD-DAD allowed to identify (-)-(2R,3R)-epicatechin in the infusion of M. rubiginosa. The same method was applied to investigate the commonly used... (Complete abstract click electronic access below)
Doutor
18
Lima, Nerilson Marques [UNESP]. « Bioprospecção em espécies de Inga (Fabaceae Mimosoideae) ». Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/138566.
Texte intégralRésumé :
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000863704.pdf: 4627489 bytes, checksum: 7ba9e741dcf10a9168b78e6f59344425 (MD5)O estudo de produtos naturais como fonte de novos agentes anticâncer torna-se de grande importância, pois mesmo devido à grande quantidade de drogas já existente para o tratamento de neoplasias, ainda não se chegou a um composto ideal que tenha maior seletividade, menos efeitos colaterais, maior potência terapêutica e menor índice de resistência. Das famílias vegetais com reconhecido potencial terapêutico destaca-se a família Fabaceae, cuja quimiossistemática atesta para uma riqueza de compostos flavonoídicos com amplo espectro de atividade biológica, inclusive antitumoral. Desta forma, o objetivo principal deste estudo foi isolar e caracterizar substâncias fenólicas a partir de frações oriundas de espécies do gênero Inga (I. laurina, I. edulis e I. marginata) selecionadas através do bioensaio com linhagens de celulas antitumorais e identificar metabólitos em mistura através de CLAE-DAD, HPLC-MS, LC-SPE-TT e Espectroscopia de RMN. A composição química destas espécies indicou uma grande variedade de ácidos aromáticos, flavonóides, taninos e triterpenos. Este trabalho permitiu a caracterização das substâncias: lupeol, éster graxo da -amirina, éster do olean-18-eno, fridelina, ácido vanílico, ácido 3,4,5-trimetoxi-benzóico, ácido gálico, galato de metila, ácido pcumárico, ácido benzóico, p-hidroxi-benzóico, ácido protocateuico, ácido tânico, ácido cafeico, ácido p-metoxicinâmico, ácido p-hidroxibenzóico, derivado metilado do ácido 4-hidroxibenzóico, ácido ferúlico, miricetina,miricetina-3-O-ramnosídeo, miricetina-3-O-(2-Ogaloil)- -ramnopiranosídeo, apigenina, quercetrina, proantocianidina A-2, procianidina B, galato de 2-ramnopiranosil-4,6-diidroxifenila, galato de 2-ramnopiranosil-3,5-diidroxifenila e do glicosídeo do 4-vinil-fenol. Através das analises por CLAE-DAD detectamos a presença de uma antocianina altamente polar na fração aquosa...
The study of natural products as a source of new anticancer agents is very important, because even due to the large amount of existing drugs for the treatment of cancer, has not yet reached an optimal compound that has greater selectivity, fewer side effects, higher potency therapeutic and index of least resistance.One of thefamilies with recognized therapeutic potential is the Fabaceae family, whose chemosystematics show an abundance of flavonoid with broad spectrum of biological activities, including antitumor. Thus, the aim of this study was to isolate and characterize phenolic compounds from fractions obtained of the genus Inga (I. laurina, I. edulis and I. marginata) selected by bioassay cytotoxic and identify metabolites in mixture by HPLC-PDA, HPLC-MS, LC-SPE-TT and NMR Spectroscopy. The chemical composition of these species indicated a wide variety of aromatic acids, flavonoids, tannins and triterpenes. This work describe the characterization of the compounds: lupeol, fatty ester of -amyrin, the olean-18-ene ester and friedelin, vanillic acid, 3,4,5-trimethoxy benzoic acid, gallic acid, gallate methyl, p-coumaric acid, benzoic acid, p-hydroxybenzoic, protocateuico acid, tannic acid, caffeic acid, p-methoxycinnamic acid, p-hydroxybenzoic acid derivative methylated of 4-hydroxybenzoic acid, ferulic acid, myricetin, myricetin-3-Orhamnoside, myricetin-3-O- (2 -O-galoil) - -rhamnopyranoside, apigenin, quercetrin, proanthocyanidin A-2 and procyanidin B, 2-rhamnopyranosyl-3,5-dihydroxyphenyl gallate, 2-rhamnopyranosyl-4,6-dihydroxyphenyl gallateand 4-vinyl-phenol. Through the analysis by HPLC-PDA detected the presence of one anthocyanin from aqueous fraction in five other anthocyanins in the methanolic fraction from seeds of I. edulis. Through the bioassay-guided fractionation was possible to obtain a fraction with high antitumor potential (ED50 = 4.0 mg/mL) that was characterized such a mixture...
19
Lima, Nerilson Marques. « Bioprospecção em espécies de Inga (Fabaceae Mimosoideae) / ». Araraquara, 2015. http://hdl.handle.net/11449/138566.
Texte intégralRésumé :
Orientador: Dulce Helena Siqueira SilvaBanca: Isabele Rodrigues Nascimento
Banca: Nivaldo Boralle
Banca: Ana Helena Januário
Banca: Luce Maria Brandão Torres
Resumo: O estudo de produtos naturais como fonte de novos agentes anticâncer torna-se de grande importância, pois mesmo devido à grande quantidade de drogas já existente para o tratamento de neoplasias, ainda não se chegou a um composto ideal que tenha maior seletividade, menos efeitos colaterais, maior potência terapêutica e menor índice de resistência. Das famílias vegetais com reconhecido potencial terapêutico destaca-se a família Fabaceae, cuja quimiossistemática atesta para uma riqueza de compostos flavonoídicos com amplo espectro de atividade biológica, inclusive antitumoral. Desta forma, o objetivo principal deste estudo foi isolar e caracterizar substâncias fenólicas a partir de frações oriundas de espécies do gênero Inga (I. laurina, I. edulis e I. marginata) selecionadas através do bioensaio com linhagens de celulas antitumorais e identificar metabólitos em mistura através de CLAE-DAD, HPLC-MS, LC-SPE-TT e Espectroscopia de RMN. A composição química destas espécies indicou uma grande variedade de ácidos aromáticos, flavonóides, taninos e triterpenos. Este trabalho permitiu a caracterização das substâncias: lupeol, éster graxo da -amirina, éster do olean-18-eno, fridelina, ácido vanílico, ácido 3,4,5-trimetoxi-benzóico, ácido gálico, galato de metila, ácido pcumárico, ácido benzóico, p-hidroxi-benzóico, ácido protocateuico, ácido tânico, ácido cafeico, ácido p-metoxicinâmico, ácido p-hidroxibenzóico, derivado metilado do ácido 4-hidroxibenzóico, ácido ferúlico, miricetina,miricetina-3-O-ramnosídeo, miricetina-3-O-(2"-Ogaloil)- -ramnopiranosídeo, apigenina, quercetrina, proantocianidina A-2, procianidina B, galato de 2-ramnopiranosil-4,6-diidroxifenila, galato de 2-ramnopiranosil-3,5-diidroxifenila e do glicosídeo do 4-vinil-fenol. Através das analises por CLAE-DAD detectamos a presença de uma antocianina altamente polar na fração aquosa...
Abstract: The study of natural products as a source of new anticancer agents is very important, because even due to the large amount of existing drugs for the treatment of cancer, has not yet reached an optimal compound that has greater selectivity, fewer side effects, higher potency therapeutic and index of least resistance.One of thefamilies with recognized therapeutic potential is the Fabaceae family, whose chemosystematics show an abundance of flavonoid with broad spectrum of biological activities, including antitumor. Thus, the aim of this study was to isolate and characterize phenolic compounds from fractions obtained of the genus Inga (I. laurina, I. edulis and I. marginata) selected by bioassay cytotoxic and identify metabolites in mixture by HPLC-PDA, HPLC-MS, LC-SPE-TT and NMR Spectroscopy. The chemical composition of these species indicated a wide variety of aromatic acids, flavonoids, tannins and triterpenes. This work describe the characterization of the compounds: lupeol, fatty ester of -amyrin, the olean-18-ene ester and friedelin, vanillic acid, 3,4,5-trimethoxy benzoic acid, gallic acid, gallate methyl, p-coumaric acid, benzoic acid, p-hydroxybenzoic, protocateuico acid, tannic acid, caffeic acid, p-methoxycinnamic acid, p-hydroxybenzoic acid derivative methylated of 4-hydroxybenzoic acid, ferulic acid, myricetin, myricetin-3-Orhamnoside, myricetin-3-O- (2 "-O-galoil) - -rhamnopyranoside, apigenin, quercetrin, proanthocyanidin A-2 and procyanidin B, 2-rhamnopyranosyl-3,5-dihydroxyphenyl gallate, 2-rhamnopyranosyl-4,6-dihydroxyphenyl gallateand 4-vinyl-phenol. Through the analysis by HPLC-PDA detected the presence of one anthocyanin from aqueous fraction in five other anthocyanins in the methanolic fraction from seeds of I. edulis. Through the bioassay-guided fractionation was possible to obtain a fraction with high antitumor potential (ED50 = 4.0 mg/mL) that was characterized such a mixture...
Doutor
20
Keßberg, Anton. « Enantioselektive Synthese bioaktiver Flavane und Isoflavane ». Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-236526.
Texte intégralRésumé :
Im Rahmen dieser Arbeit wird eine neuartige Deoxygenierungskaskade von Flavanonen bzw. Isoflavanonen via asymmetrischer Transferhydrierung (ATH) beschrieben. Diese Methodik ermöglicht einen einstufigen Zugang zu enantiomerenreinen Flavanen bzw. Isoflavanen aus entsprechenden racemischen Ketonen. Unter Verwendung der ATH-Deoxygenierungskaskade werden hoch enantioselektive Naturstoffsynthesen elaboriert. So erfolgt eine effiziente Darstellung der Flavane Brosimin A, Brosimin B, Brosimacutin L, Kazinol U und 7,3‘-Dihydroxy-4‘-methoxyflavan. Darüber hinaus wird mittels dynamischer kinetischer Racematspaltung die Totalsynthese der Isoflavane Equol, Manuifolin K und Eryzerin D beschrieben.
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Bustos, Salgado Paola. « Biopharmaceutical study of therapeutic efficacy of nanostructured formulations made from products of natural origin ». Doctoral thesis, Universitat de Barcelona, 2021. http://hdl.handle.net/10803/673940.
Texte intégralRésumé :
This research work was aimed at the characterization in vitro, ex vivo and in vivo of nanostructured systems which independently contain a natural flavanone extracted from Eysenhardtia platycarpa and another four flavanones obtained through semi-synthesis of the first flavanone with the objective of providing evidence of their efficaciousness as anti-inflammatory cutaneous agents. Initially the flavanone was isolated from its natural source, and following on from this, the derivatives were obtained through chemical reactions of acetylation, methylation, cyclization and vinyl cyclization. Calculations were made in silico using computational programs like Molinspiration and PASS Online. These gave the theoretical physio-chemical properties of the flavanones and estimated the profile of their probable anti-inflammatory activity. An analytical methodology was used for the quantification of the flavanones with High Performance Liquid Chromatography (HPLC) in samples that crossed human skin in an ex vivo study. The objective was to demonstrate that an analytical method had been selected that did not cause any interference from the biological components due to the tissue with which we worked. The results showed that the method was lineal, exact and precise in the assayed concentrations interval (1.56 - 200 µg/mL). Afterwards, nano-structured formulations were prepared individually: they contained each flavanone at 0.5 % and the excipients were: Labrasol®, Labrafac® lipophile, Propylene glycol and Plurol Oleic®. These formulations were morphologically and physio-chemically characterized. The results obtained revealed that the flavanones formulations (FF) were suitable for topical administration. An in vitro assay was carried out of the liberation of the flavanones from their individual formulation, using a dialysis membrane with a system of Franz type cells to guarantee that the formulation liberated the flavanones and allowed there to be a sufficient quantity of each component susceptible to being permeated in human skin. Immediately afterwards, ex vivo studies were realized using human skin with the objective of evaluating the permeation profile of the flavanones contained in dissolution individually and in the formulations. The study demonstrated that the quantity of flavanone permeated and retained in the skin was different, depending on the flavanone assayed. This was probably due to the different molecular interactions of the functional groups with the tissue components. The flavanones derived were retained in the skin in greater quantity than natural flavanone. Finally, an in vivo assay was carried out on the anti-inflammatory efficaciousness in a model of rat’s auricular edema induced by arachidonic acid. The results demonstrated that the flavanones were capable of reducing the edema (swelling) and the formulation excipients did not influence in the biological activity. The formulations turned out to be more effective than the reference pharmaceutical drug used in this study (sodium diclofenac gel). It was shown that the structural modification of the natural flavanone improved the therapeutic activity in which the derived methylated and cyclized vinyl stood out. These results are in concordance with the results obtained in the evaluation of the cytokines expression (IL-1β, IL-6 y TNF-α) carried out, and moreover allowed the advantage of the use of nano-structured systems in making the flavanones more effective to be shown in comparison with flavanones assayed in dissolution.El presente trabajo de investigación versa sobre la caracterización in vitro, ex vivo e in vivo de sistemas nanoestructurados que contienen de forma independiente una flavanona natural extraída de Eysenhardtia platycarpa y cuatro flavanonas obtenidas mediante semi-síntesis de la primera, con el objetivo de evidenciar su eficacia como agentes antiinflamatorios cutáneos. Inicialmente se aisló la flavanona de su fuente natural seguida de la obtención de los derivados mediante las reacciones químicas acetilación, metilación, ciclación y vinilo ciclación. Se realizaron cálculos in silico utilizando programas computacionales como Molinspiration y PASS Online para obtener las propiedades fisicoquímicas teóricas de las flavanonas y estimar su probable perfil de actividad antiinflamatoria. Se validó una metodología analítica para la cuantificación de las flavanonas por cromatografía líquida de alta eficacia (HPLC) en muestras que atravesaron piel humana en un estudio ex vivo. Lo anterior con el objeto de demostrar una selectividad del método analítico planteado sin que hubiese ninguna interferencia provocada por los componentes biológicos propios del tejido con el que se trabajaría. Los resultados mostraron que el método es lineal, exacto y preciso en el intervalo de concentraciones ensayadas (1.56 - 200 µg/mL). Posteriormente, se prepararon individualmente las formulaciones nanoestructuradas que contenían al 0.5 % cada flavanona y como excipientes: Labrasol®, Labrafac®, Propilenglicol y Plurol Oleico®. Dichas formulaciones fueron caracterizadas morfológica y fisicoquímicamente. Los resultados obtenidos revelaron que las formulaciones de las flavanonas (FF) eran adecuadas para su administración tópica. Se llevó a cabo un ensayo in vitro de liberación de las flavanonas desde su formulación individual, utilizando una membrana de diálisis en sistemas de celdas tipo Franz para garantizar que la formulación libera las flavanonas y permite disponer de cantidad suficiente de cada compuesto susceptible de ser permeado en piel humana. Seguidamente, se realizaron estudios ex vivo utilizando piel humana con el propósito de evaluar el perfil de permeación de las flavanonas contenidas en disolución de forma individual y en las formulaciones. El estudio demostró que la cantidad de flavanona permeada y retenida en la piel fue diferente dependiendo de la flavanona ensayada; probablemente debida a las diferentes interacciones molecular de sus grupos funcionales con los componentes del tejido. Las flavanonas derivadas se retuvieron en mayor cantidad en piel que la flavanona natural. Finalmente, se desarrolló un ensayo in vivo de eficacia antiinflamatoria en un modelo de edema auricular de rata inducido por ácido araquidónico. Los resultados demostraron que las flavanonas fueron capaces de reducir el edema y los excipientes de las formulaciones no influyeron en la actividad biológica. Las formulaciones resultaron ser más efectivas que el fármaco de referencia usado en este estudio (gel de diclofenaco sódico). Se comprobó que la modificación estructural de la flavanona natural mejoró la actividad terapéutica destacando los derivados metilados y vinilo ciclizados. Estos resultados se encuentran en concordancia con los obtenidos de la evaluación de expresión de las citosinas (IL-1β, IL-6 y TNF-α) realizado y además, permitió evidenciar la ventaja del uso de sistemas nanoestructurados para disponer las flavanonas, en comparación con las flavanonas ensayadas en disolución.
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Albuquerque, Irineu Lima de. « Estudo dos constituintes quÃmicos de duas amostras de prÃpolis : Alto Santo - Cearà e Passa Quatro - Minas Gerais ». Universidade Federal do CearÃ, 2007. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1862.
Texte intégralRésumé :
nÃo hÃPrÃpolis, palavra de origem grega e significa a defesa da cidade. Usado na colmÃia para fechar frestas, garantindo a proteÃÃo contra microorganismos. Diversas propriedades foram relatadas terapeuticamente como: bactericida, fungicida, antivÃrus, antiinflamatÃria. As amostras de prÃpolis brasileiras podem ser classificados em 13 grupos, baseados nas caracterÃsticas fÃsico-quÃmicas e classificadas da seguinte maneira: cinco no Sul do Brasil (grupo 3), um no Sudeste (grupo 12) e seis no Nordeste (grupo 7). O trabalho teve como objetivo a investigaÃÃo fitoquÃmica de duas amostras de prÃpolis: uma de Alto Santo - Ceara e outra de Minas Gerais â Brasil, alÃm da determinaÃÃo da atividade biolÃgica e antioxidante. Da amostra de prÃpolis do CearÃ, foram identificados: triterpenos (lupeol, Ãcido canÃrico, lupenona e germanicona); flavonoides (quercetina, canferol, acacetina, 3-(4-metoxifenila) acrilato de 2(E)-2-metoxifenila-5-(5-hidroxi-3,7-dimetoxi-4-oxo-4H-cromen-2-ila). Da prÃpolis de Minas Gerais popularmente chamada de prÃpolis verde, obteve-se: Ãcido p-cumaric, Ãcido (E)-3-(3,4-dihidroxifenila) propenÃico e uma mistura dos Ãcidos: Ãcido (E)-3-(4-hidroxifenila) propenÃico, Ãcido 3-phenilpropanÃico e Ãcido 3-(4-hidroxifenila) propanÃico. Do lupeol obteve-se uma sÃrie de derivados, entre eles: o produto oxidado e os Ãsteres no carbono-3. Os compostos e os derivatives puros do lupeol foram identificados por mÃtodos espectroscÃpicos tais como IR, o RMN 1H e 13C CG/EM. Extrato de prÃpolis e compostos puros isolados foram avaliados para a atividade antioxidante usando o mÃtodo de captura de radical DPPH (2,2-difenila-1-picril-hidrazila) e os resultados mostraram a atividade muito boa para extratos e para os flavonÃides, os triterpenos mostraram uma atividade pequena. Do Ãleo essencial da prÃpolis de Minas Gerais, identificaram-se os constituintes classificados como monoterpenos oxigenados (0,3%), hidrocarbonetos sesquiterpenos (65,18%), sesquiterpenos oxigenados (23,64%), e derivados do Ãcido cinÃmico (6,17%). Foram identificados 24 constituintes, representando 97,7% do Ãleo, e os compostos principais definidos como: E-nelolidol (17,14%), E-cariofileno (13,38%) e selin-3,7(11)-dieno (10,35%) foram os mais abundantes. O Ãleo foi caracterizado com alta percentagem de hidrocarbonetos sesquiterpenos e sesquiterpenos oxigenados. A partir da prÃpolis de Minas Gerais, material de partida para a produÃÃo de pà liofilizado, produziu-se prÃpolis solÃvel em Ãgua, obtida de uma mistura com soluÃÃo de L-lisina e PVP. O liofilizado terà destino para testes biolÃgicos.
Propolis, word has the Greek origin, and means city defense. Used in the beehive to forbid openings, guaranteeing protection against microorganisms. Several therapeutically properties were reported such as: bactericidal, fungicidal, antivirus, anti-inflammatory. Brazilian propolis can be classified in 13 groups, based on the physical-chemistry characteristics classified as: five in the South of Brazil (group 3), one in Southeast (group 12) and six in the Northeast (group 7). The present work has a goal the phytochemical investigation of two samples of propolis: one from Alto Santo - Cearà and other from Minas Gerais - Brasil and determination of biological activity. From a sample of propolis of CearÃ, were identified: triterpenes (lupeol, acid canaric, lupenone and germanicone); flavonoids (kercetin, kanferol, acacetine, 3-(4-methoxyphenyl) acrilate of 2-(E)-2-methoxyphenil-5-(5-hydroxy-3,7-dimethoxy-4-oxo-4H-cromene-2-il). For the sample propolis of Minas Gerais popularly called âgreen propolisâ were identified p-cumaric acid, (E)-3-(3,4-dihidroxyphenyl) propenoic acid and a mixture of acid ones: (E)-3-(4-hydroxyphenyl) propenoic acid, 3-phenylpropanoic acid and 3-(4-hydroxiphenil) propanoic acid. From lupeol a serie of derivative were obtained including oxidation and esters at carbon-3. Pure compounds and lupeol derivatives were identified by spectroscopic methods such as IR, 1H and 13C NMR and MS. Propolis extracts and pure compounds were evaluated for scavenger activity using DPPH (2,2-diphenyl,1-picril-hidrazil) bioassay and results showed very good activity for extracts and for flavonoids where as triterpens showed a week activity. The essential oil of the propolis from Minas Gerais obtained by hydrodestillation process was analyzed by CG-MS techniques and composition was defined as: oxygenated monoterpenes (0,30%), hydrocarbons sesquiterpenes (65,18%), sesquiterpenes oxigenated (23,64%), and derivatives of the cinamic acid (6,17%). Twenty constituent were identified representing 97.7% and major compound defined as: E-nelolidol (17,14%), E-cariofilene (13,38%) and selin-3,7(11)-dien (10,35%). The oil was characterized with high percentage of hydrocarbons sesquiterpenes and oxygenated sesquiterpenes. The green propolis of Minas Gerais was used as material for the lyophilized drug production. From the propolis water soluble together with L-lysine and a polymer PVP was obtained a power and it is using for biological tests as anticancer agent.
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Cavarischia, Claudia. « Synthesis of natural organic compounds via Palladium-catalyzed reactions ». Doctoral thesis, La Sapienza, 2005. http://hdl.handle.net/11573/917350.
Texte intégral
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Kennedy, Michael James. « Natural and enhanced wood durability from pine heartwood phenolics ». Thesis, Queensland University of Technology, 1996. https://eprints.qut.edu.au/107122/1/z%20T%28S%29%20108%20Natural%20and%20enhanced%20wood%20durability%20fro%20pine%20heartwood%20phenolics.pdf.
Texte intégralRésumé :
Wood is a naturally occurring, complex, structured, polymeric material comprised of a structural matrix in which are embedded a vast variety of extractible compounds. The organic carbon-rich matrix is susceptible to biodeterioration by a wide range of bacterial, fungal, insect and other organisms, despite protective effects of the extractives. Wood preservatives developed over the past 50 years have provided efficient ways of preventing biodeterioration, but many of them are under threat from
an increasingly chemophobic populace. Naturally bioactive wood extractives offer promise of control of many wood destroying organisms, and may be more acceptable
than these more powerful synthetic biocides. Phenolic compounds, relatively abundant extractives from the heartwood of Pinus spp., plantation-grown worldwide,
were evaluated for bioactivity.
Heartwood from Pinus spp. containing elevated phenolic concentrations was more resistant to subterranean termites than that from species characterized by low phenolics. While the stilbene phenolics were poorly related to resistance, the flavonoid phenolics appeared to be more closely associated with resistance. However, unspecified additional heartwood compounds contributed strongly to termite resistance. Both Pinus el/iottii and Pinus caribaea, previously classed with Pinus radiata as susceptible to termite attack, were naturally resistant to two significant Australian termite species. Acceptance of this resistance has enabled previous limitations on unpenetrated heartwood in these spp. to be removed from Australian requirements for preservative treatment against termites, with consequent economic benefit to the preservative treatment industry and consumers.
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Bezerra, Jaqueline de Araújo. « Estudo químico de Piper Peltatum l. (Piperaceae) e Commelina Erecta l. (Commelinaceae) ». Universidade Federal do Amazonas, 2014. http://tede.ufam.edu.br/handle/tede/4308.
Texte intégralRésumé :
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Piper peltatum L. and Commelina erecta L. are tropical species widely distributed in the Amazon region and heavily used by provincials Amazon, for its hardiness, ease of collection and cultivation, to curing several diseases, especially inflammatory. In this work has been performed phytochemical studies and evaluations of antioxidant activity of these species, aiming to contribute to it chemical knowledge, adding value to traditional knowledges. Essential oils from the leaves and hexane, ethyl acetate and ethanol extracts of the leaves, stems and inflorescences of P. peltatum were investigated. Similarly, were studied extracts of leaves and stems of C. erecta and also analyzed its hydro-alcoholic extract (30%) of its flowers. The essential oils of P. peltatum presented as main constituents β-caryophyllene (19.9 to 36.9%), germacrene D (5.8 to 18.8%), α-humulene (4.9 to 6.3%), bicyclogermacrene (3.3 to 10.8), caryophyllene oxide - (3.3-8.3%), E-nerolidol (2.9 to 6.1%) and phytol (1.7 to 8.4%). From the leaves extracts of P. peltatum were isolated, diterpene phytol, a mixture of steroid sitosterol, stigmasterol and campesterol, the flavonoid 5-hydroxy-4 ',7-dimethoxyflavone and identified the 4-nerolidylcatechol, the A, B, and C peltatols; from inflorescence were isolated 4-nerolidylcatechol and peltatol A, as well as identified the B and C peltatols and p-hydroxybenzoic acid; In the stems have been identified cinnamic acid, the uridine and adenosine nucleosides,the uracil base, 4-nerolidylcatechol and A, B and C peltatols. From the ethyl acetate extract of C. erecta stems were isolated the flavonoid luteolin and a mixture of steroids glycosides. In ethyl acetate and ethanol extracts from stems of C. erecta were identified saccharinic acid lactone, shikimic acid, flavonoids luteolin, quercitrin, isoquercitrin, the uridine nucleoside. In the ethyl acetate and ethanol extracts from stems, the saccharinic acid lactone and shikimic acid are major constituents, respectively. In the ethanol leaf extract were identified shikimic acid, 5-cafeoilshikimic acid, the flavonoids orientin, isoschaftoside, 8-C-pentosyl-luteolin, the base uracil and uridine and adenosine nucleosides, and in the hydroalcoholic extract of flowers were identified the isovitexin and vitexin flavonoids C-glycosides. The compounds structures were determined by extensive studies by nuclear magnetic resonance spectroscopy, one-dimensional (1D) and two dimensional (2D) and/or mass spectrometry. The most effective extracts as the scavenging activity of DPPH and ABTS radicals were the ethanol 96% of the inflorescence of P. peltatum (IC50 37.8 and 34.1 μg/mL) and leaves of C. erecta (IC50 50.0 and 65.0 μg/mL). The constitution of these extracts presents phenolic compounds that contribute to antioxidant activity, as 4-nerolidylcatechol for P. peltatum, orientin and luteolin for C. erecta, compatible with the popular use of the species, stimulating the continuation of their investigations.
Piper peltatum L. e Commelina erecta L. são espécies tropicais largamente distribuídas na região Amazônica e muito utilizadas pelos interioranos do Amazonas, devido a sua rusticidade, facilidade de coleta e cultivo, para cura de diversas enfermidades, em especial, processos inflamatórios. Neste trabalho, foram realizados estudos fitoquímicos e avaliação da atividade antioxidante, visando contribuir para o conhecimento químico destas espécies, agregando valor ao conhecimento tradicional. Foram investigados os óleos essenciais das folhas e os extratos hexânicos, em acetato de etila e etanólicos das folhas, caules e inflorescências de P. peltatum. Similarmente, foram estudados os extratos de folhas e caules de C. erecta e analisado o extrato hidroalcoólico (30%) de suas flores. Análises dos óleos essenciais de P. peltatum reveleram como principais constituintes: β-cariofileno (19,9 - 36,9%), germacreno D (5,8 - 18,8%), α-humuleno (4,9 - 6,3%), biciclogermacreno (3,3 - 10,8), óxido de cariofileno (3,3 - 8,3%), E-nerolidol (2,9 - 6,1%) e fitol (1,7 - 8,4%). A partir dos extratos das folhas de P. peltatum foram isolados o diterpeno fitol, uma mistura dos esteroides (sitosterol, estigmasterol e campesterol), o flavonoide 5-hidroxi-4’,7-dimetoxiflavona e identificados, o 4-nerolidilcatecol e os peltatóis A, B e C; da inflorescência foram isolados o 4-nerolidilcatecol e o peltatol A, bem como identificados os peltatóis B, C e o ácido p-hidroxibenzóico; nos caules foram identificados o ácido cinâmico, os nucleosídeos uridina e adenosina, e a base uracila, 4-nerolidilcatecol e os peltatóis A, B e C. A partir do extrato em acetato de etila dos caules de C. erecta foram isolados o flavonoide luteolina e uma mistura de esteroides glicosilados. A partir dos extratos em acetato de etila e etanólico dos caules de C. erecta foram identificados a lactona do ácido sacarínico, o ácido chiquímico, os flavonoides quercitrina e isoquercitrina, bem como o nucleosídeo uridina. Nos extratos em acetato de etila e etanólico dos caules, a lactona do ácido sacarínico e o ácido chiquímico são os constituintes majoritários, respectivamente. No extrato etanólico das folhas foram identificados os ácidos chiquímico, 5-cafeoilchiquímico, os flavonoides orientina, isoschaftoside, 8-C-pentosil-luteolina, a base uracila e os nucleosídeos uridina e adenosina, e no extrato hidroalcoólico das flores, os flavonoides C-glicosídeos vitexina e isovitexina. Os compostos tiveram suas estruturas determinadas por extensivos estudos de espectroscopia de Ressonância Magnética Nuclear unidimensional (1D) e bidimensional (2D) e/ou Espectrometria de Massas. Os extratos mais eficientes quanto à atividade sequestrante dos radicais DPPH. e ABTS+. foram os etanólicos a 96% da inflorescência de P. peltatum (CI50 37,8 e 34,1 μg/mL) e das folhas de C. erecta (CI50 50,0 e 65,0 μg/mL). Estes extratos apresentam em sua constituição compostos fenólicos, como o 4-nerolidilcatecol para P. peltatum, luteolina e orientina para C. erecta, aos quais podem ser atribuídas atividades antioxidantes. Esses resultados são compatíveis com o uso popular das espécies, o que estimula a continuação dos estudos.
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Domínguez, Villegas Valeri. « Estudio biofarmacéutico de flavanonas isoprenílicas antiinflamatorias libres y vehiculizadas en sistemas nanoestructurados para aplicación tópica ». Doctoral thesis, Universitat de Barcelona, 2014. http://hdl.handle.net/10803/134889.
Texte intégralRésumé :
Los tratamientos considerados para el dolor y la inflamación han demostrado efectos colaterales, por ello, el descubrimiento e investigación de nuevos fármacos de origen natural son considerados como alternativa favorable. Los flavonoides comprenden un grupo de compuestos del tipo fenólico que abarcan una gran variedad de sustancias dentro de los Productos Naturales.
Es por ello que en el presente trabajo se asilaron cuatro flavanonas isoprenílicas: 5, 7-dihidroxi-6-metil-8-prenilflavanona (I), 5, 7-dihidroxi-6-metil-8-prenil-4’-metoxi-flavanona (II), 5, 7-dihidroxi-6-prenilflavanona (III) y 5-hidroxi-7-metoxi-6-prenilflavanona (IV) a partir del extracto metanólico del las hojas de la especie vegetal Eysenhardtia platycarpa. A estas flavanonas se les evaluó su eficacia antiinflamatoria en un modelo de TPA en oreja de ratón, su capacidad antioxidante utilizando DPPH como radical libre y finalmente se hicieron pruebas de citotoxicidad frente a Artemia salina.
Posteriormente, se elaboraron nanoformulaciones, en específico nanoemulsiones (NEs) y nanopartículas (NPs) a partir de las cuatro flavanonas Las NPs fueron del tipo polimérico preparadas mediante el método del desplazamiento del disolvente descrito por Fessi utilizando como polímero el PLGA 50/50 a la concentración de 1.5 mg/mL de principio activo. Estas NPs mostraron un tamaño de partícula medio de 156 - 202 nm con una carga negativa entre -25 and -30 mV. Los estudios de microscopía de transmisión electrónica (TEM) evidencian que las NPs tienen forma esférica obteniéndose de esta manera nanoesferas con un patrón denso uniformemente distribuido.
Para el caso de las NEs se eleboraron empleando el método de pesada directa a una concentración de 0.5 % de principio activo. Los estudios de TEM y DLS (Dynamic light scattering) indican que se obtuvieron NEs del tipo W/O, de forma esférica y una estructura micelar de las gotas que oscilaban entre 60 y 70 nm; obteniéndose un menor tamaño de gotícula que en el caso de las NPs.
A partir de las NPs y NEs se realizaron ensayos de liberación donde se encontró que los compuestos vehiculizados en nanopartículas liberan más rápido que en naoemulsiones; a las 2 h y a las 10 h. respectivamente y en ambos casos, las flavanonas (I) y (III) son las que mayor cantidad de fármaco liberan a esos tiempos. De los ensayos de permeación se observó que la constante de permeación y la cantidad retenida en piel se ven incrementados para las flavanonas (I), (II) y (IV) cuando son vehiculizadas en NPs.
Con base a los resultados de la presente investigación se considera que la flavanona 5-hidroxi-7-metoxi-6-prenil flavanona (III) vehiculizada en nanoemulsión y nanopartículas poliméricas presenta los mejores resultados de permeación y actividad antiinflamatoria por lo que puede ser considerado un potencial agente alternativo antiinflamatorio de uso tópico.The clinically used antiinflammatory drugs suffer from the disadvantage of side effects, though the discovery and research of new natural drugs are a better alternative. Flavonoids are a wide group of natural phenolic compounds. In the present research, some nanoformulations were elaborated, specifically nanoemulsions (NEs) and nanoparticles (NPs), from four isoprenylic flavanones: 5, 7-dihydroxy-6-metil-8-prenylflavanone (I), 5, 7-dihydroxy-6-metil-8-prenyl-4’-methoxy-flavanone (II), 5, 7-dihydroxy-6-prenylflavanone (III) y 5-hydroxy-7-methoxy-6-prenylflavanone (IV) for using them as topical antiinflamatory drugs. The NPs were polimerycal compounds prepared by the solvent displacement technique described by Fessi using the PLGA 50/50 as a polymer (Concentration of active: 1.5 mg/mL). These NPs showed an average particle size of 156-202 nm with a negative charge between -25 and -30 mV. Microscopical studies (TEM) reveal that the NPs have a spherical shape, getting then nanospheres with a dense pattern homogeneously distributed. In the case of the NEs, they were prepared using the direct weighing method at a 0.5 % concentration of active. The TEM and DLS (Dynamic light scattering) studies confirmed that all W/O NEs were obtained, in round shape and a micellar structure of the drops between 60 and 70 nm; whereas in the NPs droplets of smaller size were obtained. Release studies revealed that the NPs vehiculized compounds release rate is higher than the one in the NEs (at 2 and 10 hours, respectively) and in both cases, flavanones (I) and (III) are the ones with the highest amount of drug released. Permeation studies showed that the permeation constant and the retained amount in skin are increased in flavanones (I), (II) and (IV) when they are vehiculized in NPs. According to the present research results we confirm that flavanone 5-dihydroxy-6-methoxy-6-prenylflavanone (III) vehiculized in NEs and polymeric NPs shows the best permeation and anti-inflammatory activity results; therefore it may be considered a potential alternative anti-inflammatory topical agent.
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Kauntz, Henriette. « Cellular and molecular targets of silibinin, a natural flavonoid, in colorectal cancer prevention and therapy ». Thesis, Strasbourg, 2012. http://www.theses.fr/2012STRAJ052/document.
Texte intégralRésumé :
Le cancer colorectal est la deuxième cause de mortalité due au cancer en Europe et aux États-Unis. Etant donné l’efficacité limitée et la toxicité élevée des agents de chimiothérapie, de nouvelles approches sont nécessaires. Le flavanolignane silybine représente le principal constituant actif du chardon-marie (Silybum marianum). Les mécanismes moléculaires des propriétés anticancéreuses de la silybine ont été étudiés dans un modèle cellulaire de progression du cancer colorectal humain : les cellules SW480 issues d’un adénocarcinome, et leurs dérivées métastatiques les cellules SW620. Les effets chimiopréventifs de la silybine ont été étudiés dans un modèle de cancérogenèse colique induite par l’azoxyméthane chez le rat. La silybine induit une mort apoptotique avec activation de la caspase-3 dans les deux lignées. L’expression des récepteurs de mort TRAIL est augmentée, et la caspase-8 activée. Le potentiel mitochondrial est perturbé provoquant une libération du cytochrome c et une activation de la caspase-9. En plus de l’activation des voies apoptotiques extrinsèque et intrinsèque la silybine induit une réponse autophagique. La combinaison de la silybine et de TRAIL, un agent anti-cancéreux prometteur, provoque une mort cellulaire synergique dans les deux lignées. Un effet synergique est aussi observé avec la combinaison de la silybine et des inhibiteurs des histones déacétylases (HDAC) : TSA et SAHA. Dans le modèle chez le rat, la silybine réduit de 50% le nombre des lésions prénéoplasiques. En conclusion, la silybine est un agent naturel intéressant pour la prévention du cancer colorectal et dans le cadre d’une combinaison avec TRAIL/des inhibiteurs d’HDACsColorectal cancer (CRC) is the second most common cause for cancer-related deaths in Europe and in the USA. Because of the limited efficacy and considerable toxicity of chemotherapeutic agents, new approaches are needed. The hepatoprotective flavonolignan silibinin is the major biologically active compound of the milk thistle (Silybum marianum).The molecular mechanisms of the anticancer properties of silibinin in CRC were studied in an in vitro model of cancer progression consisting of the adenocarcinoma cell line SW480 and its derived metastatic cell line SW620. Its chemopreventive effects were assessed in an in vivo model of azoxymethane-induced colon carcinogenesis in the rat. Silibinin induced apoptotic cell death with activation of caspase-3 in both cell lines. The expression of death receptors was upregulated, and caspase-8 was activated. The potential of the mitochondrial membrane was perturbed permitting the release of cytochrome c and the activation of caspase-9. Besides the activation of the extrinsic and the intrinsic apoptotic pathway, silibinin induced an autophagic response. Combination of silibinin and TRAIL, a promising anticancer agent selectively inducing apoptosis in cancer cells, induced synergistic cell death in both cell lines. Synergy in cell death induction was also observed by the combination of silibinin and the histone deacetylase (HDAC) inhibitors TSA and SAHA. In the preclinical model in the rat, silibinin administration was able to reduce by half the number of preneoplastic lesions present in the colon. In conclusion, silibinin is a promising natural agent for colon cancer chemoprevention and for combination therapy with TRAIL/HDAC inhibitors
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HADI, L. ABDEL. « THE NATURAL FLAVONOID LUTEOLIN INDUCES APOPTOSIS IN COLON CANCER CELLS BY DYSREGULATING THE SPHINGOLIPID RHEOSTAT ». Doctoral thesis, Università degli Studi di Milano, 2014. http://hdl.handle.net/2434/232572.
Texte intégralRésumé :
Colorectal cancer is one of the most common malignancies and a leading cause of cancer death in the world. More powerful and safer therapeutic approaches are urgently needed to reduce mortality and garner better curative effects. In this regard, dietary supplements capable of preventing carcinogenesis and inhibiting the growth of colon carcinoma cells have generated intense interest. Luteolin (LU), a common dietary flavonoids, has emerged as a powerful anticancer agents able to sensitize different cancer cells, including colon cancer ones, to therapeutic-induced cytotoxicity. However, the molecular mechanisms underlying LU effects in colon cancer are largely unknown.
Sphingolipids have critical functions as signaling molecules. In particular, Ceramide (Cer) and Sphingosine-1-phosphate (S1P) are involved as key antagonist mediators in regulating crucial cell responses such as proliferation and apoptosis. Cer can act as a second messenger, and, by activating a variety of signaling pathways, is able to promote growth arrest, apoptosis, or cell differentiation. To the opposite, the sphingoid mediator S1P can act as a potent mitogen and survival factor for a variety of cell types. These two lipids together form the “sphingolipid rheostat” regulating the balance between cell growth and cell death.
The objective of our study was to investigate the effects and the molecular mechanisms of LU in colon cancer, focusing on the role of the bioactive sphingoid molecules Cer and S1P. To this purpose, we used the Caco-2 cell line, obtained from a human colon adenocarcinoma, as cell model of both colon cancer cells, and differentiated intestinal enterocytes. Indeed, in long-term culture, these cells undergo a spontaneous differentiation into polarized cells, representing so far the best available in vitro model of absorptive enterocytes. These two models might thus allow to distinguish the potential LU effects on colon cancer cells in comparison to their healthy counterparts.
At first, we characterized the morphological and biochemical features of both models. We found that Caco-2 cell differentiation was accompanied by the formation of “domes” across the monolayer, known as characteristic structures of differentiated cells, and indicative of their property of absorptive epithelium. In addition, the activity of the alkaline phosphatase, a membrane-associated hydrolase was found significantly increased in differentiated Caco-2 cells compared to the tumoural cancer ones. Furthermore, we found that Caco-2 differentiation was associated with a reduction of the phospholipids/protein ratio, and whereas phosphatidylcholine was the most abundant phospholipid species of tumoural cells, phosphatidylethanolamine prevailed in the differentiated ones. Moreover, phosphatidylethanolamine plasmalogen, a quantitative relevant species in the cancer cells, exhibited a marked decrease with intestinal differentiation.
As far as the sphingolipid composition concerns, we first demonstrated that Caco-2 differentiation was associated to an increase in the total amount of sphingolipids, including Sphingomyelin (SM), the major component and precursor of both Cer and S1P, and above all ceramide. Since the SM hydrolysis, triggered by Sphingomyelinases (SMases), has been implicated in colon tumourigenesis, we then evaluated whether changes in the activity of the known different SMases (the neutral (N-SMase) and alkaline (Alk-SMase) enzymes) occur with cell differentiation. We found that the Alk-SMase activity which was barely detectable in tumoural cancer cells, significantly increased in differentiated ones. The high level of this enzyme is consistent with its presence in the apical brush border, characteristic of intestinal cells. Interestingly a significant increase in the N-SMase was observed in the differentiated Caco-2 cells suggesting a role for this enzyme in intestinal cells. Prompted by these data indicating that the SM hydrolytic potential is enhanced in differentiated Caco-2 cells, we then investigated SM metabolism in both tumoural and differentiated cells. We found that the tumoural cells were much more rapid in the production of Cer from SM than the differentiated ones, and that Cer turnover was present and rapid in both cell types. Inhibition of N-SMase activity, the most abundant enzyme, resulted in no variation of Cer formation in both types of cells, suggesting that the lysosomal acid SMase (A-SMase) is involved in SM degradation. After this characterization, we then evaluated the effect of LU on the tumoural and intestinal cells. Interestingly, we found that the flavonoid exhibited a potent cytotoxic effect on tumoural cells, by inducing apoptosis, without affecting the viability of differentiated cells.
Instead, we found that LU induces an increase in intracellular Cer level with a more pronounced trend in tumoural cells. Based on these results we examined whether Cer is involved in the mechanism of LU-induced apoptosis. Notably we obtained that conditions leading to enhance the Cer content in colon cancer cells, as treatment with short-chain Cer analogues and inhibitor of sphingomyelin synthase (SM-synthase) were succeeded by inducing apoptosis in tumoural cells, thus mimicking the LU effect.
Furthermore, we evaluated the possible effect of LU on the formation of Cer and S1P in tumoural Caco-2 cells. Pulse experiments showed that treatment with LU induced a dose-dependent increase in Cer, paralleled by a concomitant decrease of both SM and glycosphingolipids synthesis. This result suggested that LU most probably acts by reducing the availability of Cer as a substrate for both SM-synthase and glucosylceramide synthase enzymes localized in the Golgi complex, possibly by inducing a defect in the common vesicular route responsible for complex SLs biosynthetic process. Fluorescent studies using a BODIPY-C5-CER, a ceramide analogue known to mimic the ER-Golgi traffic of natural Cer in living cells, supported the presence of an aberrant traffic of Cer during LU treatment. Furthermore, pulse experiments using treatment with Brefeldin A, known to induce a retrograde merging of Golgi membranes with the ER, demonstrated that LU was not more able to exert alterations of Cer metabolism, thus indicating that the ER-Golgi traffic of Cer is the site of LU action.
In parallel, different protein kinases, including Akt have been shown to regulate ER to Golgi traffic. In addition, a study in our laboratory reported for the first time a putative role of PI3K /Akt pathway in the regulation of the vesicle-mediated movements of Cer in the ER-Golgi district. Prompted by these findings, pulse experiments using LY294002, a representative PI3K inhibitor, showed that, LY294002 and subsequently the inhibition of PI3K/Akt had the same effect on the Cer metabolism observed during LU treatment. Furthermore, we obtained that LU strongly inhibited the Akt phosphorylation as a downstream response to PI3K inhibition. Taken together, it emerges that blockade of PI3K by LU and subsequently the downregulation of PI3K/Akt pathway is considered at least one of the mechanisms responsible for the effect of this flavonoid on Cer trafficking observed in our tumoural cell model
Further analyses revealed that LU was able to alter not only Cer content but also to decrease the endogenous S1P level inducing thereby a shift of the “sphingolipid balance” to the side of death. Based on this result, we demonstrated for the first time that LU was able to act as inhibitor of Sphingosine kinase (SPHK) activity in tumoural cells, especially SPHKII, the up-regulated isoform in our cancer cell model, exhibiting only a modest effect on SPHKI.
Furthermore, in order to gain deeper insights into the role of the “Sphingolipid rheostat” in mediating the effect of LU, we attempted to push the balance towards S1P with addition of exogenous S1P. The results demonstrated that S1P conferred a significant resistance of colon cancer cells to the cytotoxic effect of LU. The mechanism by which S1P acts as LU-antagonist was proved to be mainly by the up-regulation of the PI3K/Akt pathway, which is able to rescue colon cancer cells from the apoptotic effect of the LU-induced increase of Cer.
Taken together, our results demonstrate, for the first time, that the dietary natural flavonoid LU induces apoptosis in colon cancer cells by targeting the “sphingolipid rheostat”, and directing the balance in favor of Cer. As the balance between Cer and S1P appears to be an important target for development of new and effective therapeutic strategies against tumour progression, LU could be a novel antitumoural agent not only in colon cancer but possibly in the treatment of other solid tumours.
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Seifriz, Ilana. « Propriedades antioxidantes de produtos de origem natural com potencial medicinal ». Florianópolis, SC, 2004. http://repositorio.ufsc.br/xmlui/handle/123456789/86865.
Texte intégralRésumé :
Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Programa de Pós-Graduação em Química.Made available in DSpace on 2012-10-21T11:28:46Z (GMT). No. of bitstreams: 1 203555.pdf: 1735912 bytes, checksum: e7644e34159f25f658f2eb91e7e44df0 (MD5)
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Oliveira, José Cândido Selva de. « Isolamento de constituintes e síntese de flavonoides encontrados em Poincianella pyramidalis (Fabaceae) e análise fitoquímica de Theobroma cacao (Malvaceae) ». Instituto de Química, 2014. http://repositorio.ufba.br/ri/handle/ri/16127.
Texte intégralRésumé :
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CNPq e CAPES
Os extratos MeOH de Poincinella pyramidalis (caatingueira), obtidas da casca da raiz (PPCR) e das flores (PPF), bem como, as frações orgânicas obtidas por partição, foram submetidas a testes de atividade citotóxica, antioxidante e anticolinesterásica. O teste citotóxico contra Artemia salina revelou atividade moderada para fase AcOEt em PPCR. Assim como, a fase AcOEt de PPCR apresentou 75% de inibição no teste anticolinesterásico. Para a atividade antioxidante, as fase AcOEt e BuOH de PPF foi a mais ativa, sendo atribuída a presença de galato de metila (PPF3). Por meio de processos cromatográficos foi possível isolar da fase DCM de PPF as substâncias PPF1 (alcoóis graxos), PPF2a-b (β–sitosterol/estigmasterol), PPF3 (galato de metila) e PPF4 (α e β–amirina). Além dessas, foram isoladas da fase hexano de PPCR ésteres metílicos (PPCR1) e o biflavonoide 5,7-dihidroxi-4´-metoxiflavona-6α-2´´´,4´´´-dihidroxi-4´´- metoxidihidrochalcona (PPCR3). Da fase hidroMeOH de PPCR foram isoladas as substâncias PPCR2 (ácido 3,3´-dimetoxi-4-hidroxielagico-4´-β-D-xilopiranosideo) e outro biflavonoide PPCR4 (5-hidroxi-7,4´-dimetoxiflavona-3α-2´´´-hidroxi-4´´´,4´´- dimetoxidihidrochalcona). Sendo PPCR3 e PPCR4 inéditas na literatura. O extrato hexano de Theobroma cacao (cacau) obtido das sementes (STC) foi analisado por RMN e revelou presença de triacilglicerideos. A otimização e fracionamento do extrato MeOH de T. cacao utilizando CCC levou ao isolamento simultâneo de teobromina (2), teofilina (3) e cafeína (4), fase móvel hexano:AcOEt (2:3) e estacionária MeOH:H2O (1:1). Um método analítico foi desenvolvido empregando HPLC/DAD com coluna fase reversa C-18 para a quantificação de 2, 3 e 4 nos extrativos em fase ácida/básica e nas frações STC6-22 e STC23-67 obtidas por CCC. Assim, os teores de 2 e 4 para no extrato MeOH de T. cacao e frações obtidas por CCC foram determinados. A teofilina (3) detectada e quantificada na fração STC6-22 em baixa concentração (0,78 mg/g) em relação a 2 e 4. A apigenina (6) foi sintetizada utilizando dois métodos distintos (“A” e “B”). O metodo “B” apresentou rendimento de 74% em uma única etapa. A síntese de derivados O-metilados forneceu bons rendimentos (> 90%). As substâncias isoladas/sintetizadas foram submetidas à atividade anticolinesterasica do qual, são inativas. As mesmas foram elucidadas a partir de dados de IV, UV, EM, α[D], RMN de 1H e 13C (BB e APT), RMN de correlação (HMQC, HSQC e HMBC).
The MeOH extracts from Poincinella pyramidalis (caatingueira), obtained of bark root (PPCR) and flowers (PPF), as well the organic fractions obtained by partition, have been tested for cytotoxicity, antioxidant and anticholinesterasic activity. The cytotoxic test against Artemia salina showed moderate activity for AcOEt phase in PPCR. Well the EtOAc phase of PPCR showed 75% inhibition on anticholinesterasic test. For the antioxidant activity, the EtOAc and BuOH phase of PPF was the most active, being attributed to the presence of methyl gallate (PPF3). For chromatographic process was possible to isolate the DCM phase of PPF the substances PPF1 (fatty alcohols), PPF2a- b (β–sitosterol/stigmasterol), PPF3 (methyl galate) and PPF4 (α- and β–amirin). Besides these, were isolated from the hexane phase PPCR methyl esters (PPCR1) and the biflavonoid 5,7-dihidroxy-4´-methoxyflavone-6α-2´´´,4´´´-dihidroxy-4´´-methoxy dihidrochalcone (PPCR3). The HidroMeOH phase of PPCR were the isolated substances PPCR2 (3,3´-dimethoxi-4-hidroxyellagicacid-4´-β-D-xylopiranoside) and other biflavonoid PPCR4 (5-hidroxy-7,4´-dimethoxyflavone-3α-2´´´-hidroxy-4´´´,4´´- dimethoxydihidrochalcone). Being PPCR3 and PPCR4 unpublished in literature. Hexane extract of Theobroma cacao (cacau) obtained from the seeds (STC) was analyzed by NMR and revealed the presence of triacylglycerides. The optimization and fractionation of MeOH extract of T. cacao using CCC led to the simultaneous isolation of theobromine (2) Theophylline (3) and caffeine (4), mobile phase hexane:EtOAc (2:3) and stationary MeOH:H2O (1:1). An analytical method was developed employing HPLC/DAD with reverse phase column C-18 for the measurement of 2, 3 and 4 in the extractives acid/base phase and the STC6-22 and STC23-67 fractions obtained by CCC. So, the levels of 2 and 4 for the MeOH extract of T. cacao and fractions obtained by CCC were determined. Theophylline (3) detected and quantified in the fraction STC6-22 low concentration (0.78 mg/g) in relation the 2 and 4. Apigenin (6) was synthesized using two different methods ("A" and "B"). The method "B" had a yield of 74% in one step. The synthesis of O-methylated derivatives provided good yields (> 90%). The isolated/synthesized substances were submitted to anticholinesterasic activity which are inactive. The same were elucidated from data of IR, UV, MS, α[D], 1H NMR and 13C NMR (BB and APT) NMR correlation (HMQC, HSQC and HMBC).
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Garcia, Fernanda. « Estudo fitoquímico da fração AcOEt do extrato etanólico das folhas de Arrabidaea brachypoda (DC) Bureau - Bignoniaceae e atividades antioxidante e inibitória da enzima mieloperoxidase das substancias isoladas / ». Araraquara : [s.n.], 2008. http://hdl.handle.net/11449/97989.
Texte intégralRésumé :
Orientador: Vanderlan da Silva BolzaniCoorientador: Claúdio Viegas Júnior
Banca: Wilson Roberto Cunha
Banca: Mary Ann Foglio
Resumo: O presente trabalho visou o estudo químico da Arrabidaea brachypoda, uma espécie pouco estudada, possuindo somente um registro de trabalho sobre o seu estudo químico na literatura. Primeiramente foi feito um trabalho de desreplicação dos extratos etanólicos dos caules, das folhas e das inflorescências em HPLC-DAD usando padrões de xantonas isoladas da A. samydoides. Observou-se que a espécie estudada não possuia xantonas como seus principais constituintes. A fração AcOEt do extrato etanólico das folhas forneceu dois flavonóis derivados de quercetina inéditos: arrabidosídeo A e arrabidosídeo B, além dos flavonóis rutina e isoquercitrina. A atividade antioxidante desses flavonóis frente ao radical DPPH foi avalidada e os valores de CI50 foram: isoquercetrina 15,10 μM, rutina 4,88 μM, arrabidosídeo A 8,95 μM e arrabidosídeo B 5,34 μM. Além disso, essas substâncias foram ensaiadas para a atividade inibitória de mieloperoxidase (MPO). Os valores de CI50 para essa atividade foram: isoquercetrina 3,75 nM, rutina 3,60 nM, arrabidosídeo A 1,80 nM e arrabidosídeo B 4,82 nM e mostraram o potencial antiinflamatório desses flavonóis.
Abstract: The scope of this work was the phytochemical study of Arrabidaea brachypoda with only one previous chemical study reported in the literature. Initially a dereplication method was applied to the barks, leaves and flowers ethanolic extracts using xanthones previously isolated from A. samydoides as standards. The crude extract of A. brachypoda did not show xanthones as major constituents. The AcOEt fraction obtained from leaves ethanolic extract yielded two new falvonols: arrabidoside A and arrabidoside B, along with isoquercitrin and rutin. The antioxidant activity of these flavonols was evaluated using DPPH and IC50 values obtained were: isoquercitrin 15,10 μM, rutin 4,88 μM, arrabidoside A 8,95 μM and arrabidoside B 5,34 μM. Inhibitory activity of mieloperoxidase enzyme of the four flavonols was also evaluated. The values of IC50 obtained were: isoquercitrin 3,75 nM, rutin 3,60 nM, arrabidoside A 1,80 nM and arrabidoside B 4,82 nM and showed de anti-inflammatory potential of these flavonols.
Mestre
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Martinez, Stephanie. « Pharmacokinetic and pharmacodynamic investigations of select natural products and nutraceuticals for human and veterinary health ». John Wiley & ; Sons, Ltd, 2013. http://hdl.handle.net/1993/31166.
Texte intégralRésumé :
Natural products are teeming with potential therapeutic agents. One group of compounds, polyphenols, from plants, exhibit anti-cancer, anti-inflammatory and anti-oxidant activities. Four polyphenolic compounds and their enantiomers were investigated in this thesis; the stilbene, 3-methoxypterostilbene, a structural analog of resveratrol, and the chiral prenylflavonoids from hops (Humulus lupulus L.); 8-prenylnaringenin, 6-prenylnaringenin and isoxanthohumol. A high performance liquid chromatography method for 3-methoxypterostilbene and enantiospecific liquid chromatography-mass spectrometry assays for the three prenylflavonoids were developed and validated. The methods allowed for quantification of these four polyphenols in biological samples and plant-based materials. Content analysis studies of 3-methoxypterostilbene and the three prenylflavonoids in traditional Chinese medicinal plants and hops-containing nutraceuticals were carried out, respectively. The pharmacokinetics of these four compounds were delineated through intravenous and oral administration in rats. 3-Methoxypterostilbene demonstrated greater bioavailability in rats than reported values for resveratrol. Enantiomeric differences in disposition parameters were observed for the three prenylflavonoids along with differences between compounds despite only small structural differences. The in vitro pharmacodynamics of these four compounds were elucidated including anti-oxidant, anti-inflammatory, anti-diabetic and cytochrome P450 modulation activities. All four compounds demonstrated a range of bioactivities related to chronic diseases and potential drug-botanical interactions. Further studies of polyphenols, especially clinical studies, are needed along with enantiospecific study when applicable to continue delineating the importance of bioactivity, pharmacokinetics and safety.
Natural products are further developed into nutraceuticals and sold over-the-counter for both human and veterinary use but are not currently required to demonstrate efficacy prior to marketing. In the final section of this thesis, Phycox®, a multi-component veterinary nutraceutical for joint health was investigated for pharmacological activity in an in vitro model of canine osteoarthritis along with select constituents. A pilot single-dose pharmacokinetic study in dogs was also undertaken. Two liquid chromatography tandem mass spectrometry methods were developed and validated to detect constituents in serum. In vitro study results indicated that Phycox® was able to reduce inflammatory mediators similar to the NSAID, carprofen, and acute pharmacokinetic results revealed that detectable concentrations of glucosamine were evident in serum. It is suggested that further clinical studies of Phycox® are warranted to optimize its usage.May 2016
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Sousa, Roberta Regina Ruela de. « Compostos naturais como moduladores de vias de transdução de sinal em celulas tumorais ». [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314328.
Texte intégralRésumé :
Orientadores: Hisroshi Aoyama, Carmen Verissima FerreiraTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: A busca por compostos que atuem especificamente no tumor e causem menos efeitos colaterais é o grande desafio da pesquisa no tratamento contra o câncer. Muitos compostos naturais extraídos de plantas têm apresentado resultados promissores como agentes moduladores de vias de transdução de sinais em diversos tipos de tumores. Os flavonóides, compostos polifenólicos encontrados em diversos alimentos como frutas, chás e vinhos, têm recebido bastante atenção em função dos seus efeitos quimiopreventivos e quimioterapêuticos. Nos últimos anos, muitos estudos relacionados à ação dos terpenos em doenças foram desenvolvidos, decorrentes das suas propriedades anti-inflamatórias, antimicrobiana, gastroprotetora e antitumoral. Entretanto, poucos estudos com enfoque molecular foram desenvolvidos para entender o mecanismo de indução de morte de células tumorais por tais compostos. O objetivo deste trabalho foi estudar a ação dos flavonóides apigenina e fisetina e do diterpeno ferruginol, sobre as vias de transdução de sinal envolvidas na proliferação e morte em células de leucemia e câncer de próstata. Todos os três compostos estudados levaram à morte das células tumorais por apoptose. As células leucêmicas tratadas com fisetina apresentaram aumento da expressão de NFkB, ativação da MAPK p38 e aumento dos níveis de fosforilação de proteínas. A apigenina, por sua vez, mostrou-se um forte inibidor de quinases, especificamente as envolvidas com a proliferação celular, como PI3K, AKT, Src e MAPK, além de induzir apoptose através da via intrínsica. O ferruginol foi capaz de inibir e/ou regular negativamente PI3K, STAT3 e STAT5, proteínas tirosinas fosfatases e proteínas quinases envolvidas com a regulação do ciclo celular. Em ambiente redutor, o efeito citotóxico do ferruginol foi drasticamente impedido, indicando que sua atividade antitumoral pode estar relacionada com a modulação do status redox. O presente trabalho mostrou que os compostos naturais fisetina, apigenina e ferruginol apresentaram um grande potencial como agentes quimioterápicos.
Abstract: The search for compounds that specifically act on tumors, with low side effects, is a great aim in the studies related to cancer treatment. Many natural compounds isolated from plants have presented promising results as modulating agents of the signal transduction pathways in several types of tumors. Flavonoids, polyphenolic compounds largely distributed in foods such as fruits, teas and wines, have been greatly focused due to their chemopreventive and chemotherapeutic effects. In the last years, many studies about the action of terpenes in diseases have been done, due to their antiinflamatory, antimicrobial, gastroprotective and antitumoral properties. However, few molecular studies have been developed to understand the mechanism of cell death induction by these compounds. The aim of this work was to define the molecular action of apigenin, fisetin and ferruginol on the signal transduction pathways involved in the leukemic and prostate cancer cells proliferation and death. All the three compounds studied provoked the cell death by apoptosis. Leukemic cells treated with fisetin presented an increase of NF?B expression and protein phosphorylation levels and activation of p38 MAPK. Apigenin showed to be a strong inhibitor of kinases involved with cellular proliferation, such as, PI3K, AKT, Src, MAPK and additionally to induce apoptosis via the intrinsic pathway. Ferruginol was able to inhibit and/or to negatively regulate PI3K, STAT3 and 5, protein tyrosine phosphatases and protein kinases involved in the regulation of the cell cycle. In reducing environment, the cytotoxic effect of ferruginol was drastically impeded, which indicates that the anti-tumoral activity of ferruginol might be related to redox status modulation. The present work showed that the natural compounds fisetin, apigenin and ferruginol presented great potential as chemotherapeutic agents.
Doutorado
Bioquimica
Doutor em Biologia Funcional e Molecular
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Cano, Rocío Yasmin. « Mecanismos de acción de flavonoides naturales sobre la proliferación de epimastigotes trypanosoma cruzi ». Bachelor's thesis, Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales, 2019. http://bdigital.uncu.edu.ar/14053.
Texte intégralRésumé :
En este trabajo se analiza el efecto de los flavonoides Xantomicrol (XML) y Salvigenina (SVG) aislados de Baccharis calliprinos ("chilca") y Apigenina (AGN) aislada de Larrea divaricata ("jarilla"), sobre el crecimiento de T. cruzi en cultivos. Para ello se utiliza epimastigotes de T. cruzi (cepa Dm28c) en cultivo axénico, cultivados en ausencia o presencia de diferentes concentraciones de los compuestos (disueltos en dimetilsulfóxido, DMSO). Todos los compuestos mostraron un efecto antiproliferativo sobre los epimastigotes, incluso a bajas concentraciones. Además, mostraron ser estables a las condiciones experimentales evaluadas y no presentaron efecto reversible. Asimismo, se observa que afectan tanto la actividad mitocondrial como los niveles de especies reactivas de oxígeno del parásito. Por último, se pudo identificar mediante microscopia óptica y electrónica, modificaciones a nivel morfológico y ultraestructural.Fil: Cano, Rocío Yasmin. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales.
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Campo, Clara Beatriz Hoffmann. « Role of the flavonoids in the natural resistance of soyabean to Heliothis virescens (F.) and Trochoplusia ni (Huebner) ». Thesis, University of Reading, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308559.
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Pereira, Luciane Dias. « Influência de fatores edáficos na composição química de cascas e sementes de jabuticaba (Myrciaria cauliflora) ». Universidade Federal de Goiás, 2016. http://repositorio.bc.ufg.br/tede/handle/tede/6011.
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Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG
Seeds and peels of jabuticaba (Myrciaria cauliflora (Mart) O. Berg) collected in the Jabuticabal Winery were separately extracted with aqueous acetone (50%). After partitioning between solvents, the fractions ethyl acetate and methanol were subjected to repeated column chromatography using Diaion HP-20 and Sephadex LH-20 as adsorbents. Pure substances and fractions were analyzed by 1H NMR and 13C, one and two dimensional, and ESI-TOF mass spectroscopy. In this work, fifteen compounds were isolated and identified: seven ellagitannins, one of them is novel, one galloyl ester, three phenolic acids, two glycosylated flavonoids, one depside and one organic acid. To optimize the extraction of phenolic compounds, a randomized experimental design was applied, using Box-Wilson central composite design for two factors. The independent variables were stirring time () and solvent volume (V), which consisted of ethanol/hydrochloric acid (9:1). Three independent experiments in duplicate were performed, as well as assays for quantitation of phenolic compounds total monomeric anthocyanins (TMA), tannins (T), total phenols (TP), and color parameters color index (CI) and tonality (Ton). According to the results, when the volume remained constant and the stirring time increased, all phenolic contents and color patterns intensified. The best conditions for greater extraction were total ultrasonic time of 75 min and solvent volume of 64 ml, yielding the concentrations of TP, T and TMA of 33.5; 7.9 and 5.57 mg g-1, and CI and Ton, 0.893 a.u. and 0.833, respectively. In the extraction of phenolic compounds from seeds, the following solvents were tested water, aqueous ethanol (50%), aqueous methanol (50%), and the latter mixture provided the highest levels of TP, T and flavonoids: 15.71; 12.65 and 64.14 mg g-1, respectively. The influence of soil on jabuticaba seed and peel chemical contents was evaluated. Data obtained from the analysis of centesimal composition, phenolic contents, color parameters and mineral nutrients of samples collected in five orchards were analyzed by canonical redundancy (RDA) and hierarchical clustering (HCA). These analyzes ordered samples in four groups: the peels in groups I and II were related to high levels of phenolics and fibers, respectively, while the tannins and flavonoids were main compounds present in the seeds of group III, the moisture content was higher in seeds of group IV. The separation of peels (Groups I and II) and seeds (Groups III and IV) in different groups was influenced by the levels of fruits nutrients, Mn2+ and Cu2+, whereas Mn2+ from soil distinguished samples of the clusters I and III from the others, II and IV, characterizing a strong influence of some soil and fruits nutrients on the chemical composition of the jabuticaba seeds and peels.
Sementes e cascas de jabuticaba (Myrciaria cauliflora (Mart.) O. Berg) coletadas na Vinícola Jabuticabal, foram extraídas separadamente com acetona:água 50%. Após partição entre solventes, as frações acetato de etila e metanólica foram submetidas a repetidas cromatografias em coluna utilizando-se Diaion HP-20 e Sephadex LH-20 como adsorventes. Substâncias puras e frações foram analisadas por RMN de 1H e 13C, uni e bidimensional e espectroscopia de massas ESI-TOF. Neste trabalho foram isolados e identificados quinze compostos sendo sete elagitaninos, um deles inédito, um éster galoílico, três ácidos fenólicos, dois flavonoides glucosilados, um depsídeo e um ácido orgânico. Para otimização da extração dos compostos fenólicos utilizou-se um delineamento experimental ao acaso, empregando-se a técnica de planejamento Box-Wilson composto central para dois fatores. Os fatores foram compostos pelo tempo de agitação () e volume de solvente (V) constituído por etanol/ácido clorídrico (9:1). Foram realizados três experimentos independentes em duplicata, além de ensaios para quantificação dos compostos fenólicos antocianinas totais monoméricas (ATM), taninos (T) e fenóis totais (FT), padrões de coloração índice de cor (IC) e tonalidade (Ton). De acordo com os resultados, quando o volume permaneceu constante e variou o tempo de agitação observou-se que todos os teores de fenóis e padrões de cor aumentaram. O tempo total de 75 min de ultrassom e volume de solvente de 64 mL apresentou maior poder de extração, obtendo-se teores de FT, T e ATM de 33,5; 7,91 e 5,57 mg g-1, com IC e Ton de 0,893 u.a. e 0,833, respectivamente. Na extração de compostos fenólicos nas sementes foram testados os solventes: água, etanol aquoso (50%) e metanol aquoso (50%), sendo que esta última mistura forneceu os maiores teores de FT, T e flavonoides: 15,71; 12,65 e 64,14 mg g-1, respectivamente. No estudo da influência do solo nas variações químicas de cascas e sementes de jabuticaba, os dados obtidos da análise de composição centesimal, compostos fenólicos, padrões de coloração e nutrientes minerais de amostras de cinco pomares foram analisados por redundância canônica (RDA) e de agrupamento hierárquico (HCA). Essas análises ordenaram as amostras em quatro grupos: as cascas do grupo I e II foram relacionadas aos altos níveis de fenóis totais e fibras, respectivamente, enquanto que os taninos e flavonoides foram os principais compostos presentes nas sementes do grupo III e o teor de umidade foi maior em sementes do grupo IV. A separação de cascas (grupos I e II) de sementes (grupos III e IV) em grupos distintos foi influenciada pelos teores dos nutrientes Mn2+ e Cu2+ dos frutos, enquanto Mn2+ do solo distinguiu amostras das classes I e III das outras, II e IV, caracterizando assim uma forte influência de alguns nutrientes dos solos e dos frutos na composição química das sementes e cascas de jabuticaba.
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Lutz, Joseph A. « Flavonoids with Novel Nicotinic Activity as Potential Pharmacotherapies to Treat Ethanol-Induced Neurotoxicity ». UKnowledge, 2014. http://uknowledge.uky.edu/pharmacy_etds/43.
Texte intégralRésumé :
Ethanol causes neurotoxicity via several mechanisms at different points in the cycle of dependence, including neuroinflammation and oxidative stress during ethanol exposure as well as excitotoxicity during ethanol withdrawal. The primary therapeutic implication is that ethanol-induced neurotoxicity requires multifunctional pharmacotherapies which reduce all mechanisms. Using an innovative pharmacological high throughput screening method on a large plant extract library we discovered flavonoids with alpha7 nicotinic acetylcholine receptor (nAChR) activity. In addition to their well-known anti-inflammatory and antioxidant properties, this novel activity means they can potentially reduce excitotoxicity and therefore makes them ideal for inhibition of ethanol-induced neurotoxicity. Rhamnetin, the candidate compound, was first found to inhibit lipopolysaccharide induced inflammation in immortalized BV2 microglia, in part, via alpha7 nAChRs. We then established an in vitro model of ethanol induced-neurotoxicity using organotypic hippocampal slice cultures which incorporated both neuroinflammatory and excitotoxic components. Neuroinflammation enhanced excitotoxicity under control conditions but the reverse was observed during ethanol withdrawal. Both mechanisms are important but their interaction is not simple. Finally, rhamnetin was evaluated in this model and found to reduce neuroinflammation and excitotoxicity associated with ethanol withdrawal. In conclusion, the studies herein provide strong evidence for alpha7 nAChRs selective flavonoids as potential pharmacotherapies for the treatment of ethanol-induced neurotoxicity and further implicate neuroinflammation, excitotoxicity, and their interaction as critical mechanisms in this pathology.
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Hokkanen, J. (Juho). « Liquid chromatography/mass spectrometry of bioactive secondary metabolites – in vivo and in vitro studies ». Doctoral thesis, Oulun yliopisto, 2013. http://urn.fi/urn:isbn:9789526200897.
Texte intégralRésumé :
Abstract Liquid chromatography (LC) combined with mass spectrometry (MS) is one of the most widely used techniques in modern analytical laboratories. Remarkable developments during the two previous decades in both techniques has made LC-MS the method of choice in various environmental, pharmaceutical and biochemical laboratories due to selectivity, sensitivity and versatility. The main focuses in this study were to develop new LC-MS methods to identify and quantify phenolic secondary metabolites in bilberry, lingonberry and hybrid bilberry, to study the biosynthesis of the main secondary metabolites (hypericin and hyperforin and their derivatives) in St John’s wort (SJW) both in vitro and in vivo (in plant), to identify in vitro metabolites of hyperforin in human liver microsomes and to identify the cytochrome P450 (CYP) enzymes responsible for their formation. Both high-performance liquid chromatography (HPLC) and ultra high-performance liquid chromatography (U-HPLC) in combination with time-of-flight (TOF) and triple quadrupole (QqQ) mass spectrometry were used in this study. Identification of 52 phenolic compounds from the leaves of bilberry, lingonberry and hybrid bilberry was accomplished. In total, seven of the identified compounds were reported for the first time in Vaccinium plants and several other compounds were reported for the first time in the studied plants. Incorporation of valine and isoleucine into acyl side chains of phloroglucinols (hyperforin and adhyperforin) via biosynthesis in shoot cultures of SJW was confirmed by using isotopically labeled amino acids and HPLC-MS/MS. Also, 29 biosynthetic in vitro products for HpPKS2 enzyme originating from SJW were identified based on accurate mass data. The metabolism of hyperforin was studied in human liver microsomes (HLM) for the first time. 57 metabolites for hyperforin were identified in the incubations with HLMs, using a substrate concentration of 1 μM. The phase I metabolism of hyperforin was suggested to rely mainly on CYP3A4 and on CYP2C familyTiivistelmä Nestekromatografia (LC) yhdistettynä massaspektrometriaan (MS) on yksi eniten käytetyistä analyysimenetelmistä nykyaikaisissa analytiikkalaboratorioissa. Viimeisten parin vuosikymmenen aikana LC-MS -laitteet ovat kehittyneet merkittävästi, ja nykyään LC-MS onkin paras menetelmä moniin ympäristö-, lääkeaine- ja biokemiallisiin laboratorioihin sen selektiivisyyden, herkkyyden ja monipuolisuuden vuoksi. Tässä väitöskirjassa kehitettiin uusia LC-MS –menetelmiä mustikan, puolukan ja mustikkapuolukan fenolisten sekundäärimetaboliittien tunnistamiseksi ja kvantitoimiseksi, mäkikuisman pääasiallisten sekundäärimetaboliittien (hyperisiini, hyperforiini ja niiden johdannaiset) tutkimiseksi in vitro- ja kasvinäytteistä sekä hyperforiinin aineenvaihduntatuotteiden tunnistamiseksi ja niitä muodostavien sytokromi P450 (CYP) entsyymien tunnistamiseksi ihmisen maksamikrosomeissa in vitro -menetelmin. Tässä työssä käytettiin sekä korkean erotuskyvyn nestekromatografia (HPLC) että ultra-korkean erotuskyvyn nestekromatografia (U-HPLC) yhdistettynä lentoaikamassaspektrometriin (TOF-MS) ja kolmoiskvadrupolimassaspektrometriin (QqQ-MS). Mustikan, puolukan ja mustikkapuolukan lehdistä tunnistettiin yhteensä 52 fenolista yhdistettä. Seitsemää näistä tunnistetuista yhdisteistä ei oltu aiemmin löydetty Vaccinium -suvun kasveista ja useat muut yhdisteistä löydettiin ensimmäistä kertaa nyt tutkituista kasveista. Valiinin ja isoleusiinin liittyminen floroglusinolien (hyperforiini ja adhyperforiini) asyylisivuketjuihin biosynteesin välityksellä varmistettiin isotoppileimattujen aminohappojen ja HPLC-MS/MS –mittausten avulla. Tässä työssä tunnistettiin myös 29 mäkikuismasta peräisin olevan HpPKS2 -entsyymin in vitro biosynteesituotetta tarkan massan mittausten avulla. Hyperforiinin metaboliaa tutkittiin ensimmäistä kertaa ihmisen maksamikrosomeissa (HLM). Hyperforiinille tunnistettiin yhteensä 57 aineenvaihduntatuotetta ihmisen maksamikrosomi-inkubaatioissa, kun hyperforiinin alkukonsentraatio oli 1 μM. Tämän tutkimuksen tulosten perusteella hyperforiinin faasi I metabolia tapahtuu pääasiassa CYP3A4:n ja CYP2C-perheen välityksellä
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Garcia, Fernanda [UNESP]. « Estudo fitoquímico da fração AcOEt do extrato etanólico das folhas de Arrabidaea brachypoda (DC) Bureau - Bignoniaceae e atividades antioxidante e inibitória da enzima mieloperoxidase das substancias isoladas ». Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/97989.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O presente trabalho visou o estudo químico da Arrabidaea brachypoda, uma espécie pouco estudada, possuindo somente um registro de trabalho sobre o seu estudo químico na literatura. Primeiramente foi feito um trabalho de desreplicação dos extratos etanólicos dos caules, das folhas e das inflorescências em HPLC-DAD usando padrões de xantonas isoladas da A. samydoides. Observou-se que a espécie estudada não possuia xantonas como seus principais constituintes. A fração AcOEt do extrato etanólico das folhas forneceu dois flavonóis derivados de quercetina inéditos: arrabidosídeo A e arrabidosídeo B, além dos flavonóis rutina e isoquercitrina. A atividade antioxidante desses flavonóis frente ao radical DPPH foi avalidada e os valores de CI50 foram: isoquercetrina 15,10 μM, rutina 4,88 μM, arrabidosídeo A 8,95 μM e arrabidosídeo B 5,34 μM. Além disso, essas substâncias foram ensaiadas para a atividade inibitória de mieloperoxidase (MPO). Os valores de CI50 para essa atividade foram: isoquercetrina 3,75 nM, rutina 3,60 nM, arrabidosídeo A 1,80 nM e arrabidosídeo B 4,82 nM e mostraram o potencial antiinflamatório desses flavonóis.
The scope of this work was the phytochemical study of Arrabidaea brachypoda with only one previous chemical study reported in the literature. Initially a dereplication method was applied to the barks, leaves and flowers ethanolic extracts using xanthones previously isolated from A. samydoides as standards. The crude extract of A. brachypoda did not show xanthones as major constituents. The AcOEt fraction obtained from leaves ethanolic extract yielded two new falvonols: arrabidoside A and arrabidoside B, along with isoquercitrin and rutin. The antioxidant activity of these flavonols was evaluated using DPPH and IC50 values obtained were: isoquercitrin 15,10 μM, rutin 4,88 μM, arrabidoside A 8,95 μM and arrabidoside B 5,34 μM. Inhibitory activity of mieloperoxidase enzyme of the four flavonols was also evaluated. The values of IC50 obtained were: isoquercitrin 3,75 nM, rutin 3,60 nM, arrabidoside A 1,80 nM and arrabidoside B 4,82 nM and showed de anti-inflammatory potential of these flavonols.
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Schlichter, Susanne. « Einfluss des Flavonoids Quercetin auf die epitheliale Barrierefunktion der humanen Kolonkarzinom-Zelllinie Caco-2 ». Phd thesis, kostenfrei, 2007. http://opus.kobv.de/ubp/volltexte/2007/1526/.
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Cruz, Mariluze Peixoto. « Isolamento e identificação de compostos bioativos de mimosa hostilis Benth ». Instituto de Química, 2013. http://repositorio.ufba.br/ri/handle/ri/16130.
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CNPq, FAPESB/PPSUS, CAPES
O presente trabalho descreve o estudo fitoquímico e a avaliação da atividade antioxidante, antimicrobiana, antionociceptiva e anti-inflamatória de Mimosa hostilis Benth que é usada para o tratamento de tosse e cicatrização de feridas. O gênero Mimosa, pertencente a família Leguminoseae e subfamília Mimosaceae (Mimosoideae) que possui cerca de 500 espécies fontes de metabólitos especiais, tais como, alcaloides, compostos fenólicos, terpenoides, saponinas, carotenoides e principalmente flavonoides. Os extratos etanólicos da casca, folhas e galhos de M. hostilis, conhecido popularmente como jurema-preta, coletado na Floresta Nacional Contendas do Sincorá, situado na região de semiárido da Bahia foi analisado por CG-EM onde foram identificados principalmente carboidratos, ácidos graxos, compostos fenólicos e terpenos. Da fração diclorometânica das folhas foram isolados o 3,4,5-tri- hidroxibenzoato de etila (FDF1) e ácido 4-hidroxibenzóico (FDF2) e os flavonoides 5,4’-di- hidroxi-7-metoxiflavanona (M1), 5,4’-di-hidroxi-7-metoxiflavona (M2), 5,6,4’-tri-hidroxi-7- metoxiflavona (M3), 5,4’-di-hidroxi-7,8-dimetoxiflavona (M4), 5,7,4’-tri-hidroxi-3- metoxiflavona (M5), 5,7,4’-tri-hidroxi-6-metoxiflavonol (M6), 5,6-di-hidroxi-7,4’- dimetoxiflavonol (M7) e 5-hidroxi-7,8,4’-trimetoxiflavonol (M8), identificados por análises espectroscópicas de RMN de 1H e de 13C, UV e por EM, que apresentaram atividade inibitória de AChE para tratamento da doença de Alzheimer. Os extratos etanólicos apresentaram atividade antioxidante similares aos obtidos pelos controles BHT e α-tocoferol, analisado pelo ensaio do radical DPPH, com destaque para o extrato da casca que possui maior teor de fenólicos totais analisado pelo método de Folin-Ciocalteu. Os extratos também foram avaliados pelo teste do β-caroteno/ácido linoleico, apresentando-se como bons sequestradores de radicais livres, assim como os controles, sendo classificados como bons bloqueadores de reações oxidativas. O extratos etanólicos de cascas e folhas foram testados quanto a CIM e CBM e apresentaram forte ação inibitória para os microrganismos Streptococcus mutans UA159, Streptococcus mutans Ingbritt 1600, Staphylococcus aureus ATCC 25923, o extrato da casca apresentou ainda atividade para Escherichia coli ATCC 25922 e o extrato das folhas para Pseudomonas aeruginosa ATCC 10145, sendo algumas atividades bactericida. Para estreptococos do grupo mutans, foi também realizado o teste de CIMA para testar a atividade antiplaca apresentando forte inibição, com destaque para o extrato das folhas, que foi usado para avaliar a inibição da formação do biofilme dental de S. mutans UA159, havendo redução da viabilidade das bactérias e do peso seco do biofilme com o tratamento tópico do extrato quando comparado ao controle clorexidina. O extrato da casca também foi avaliado in vivo quanto à atividade antinociceptiva e anti-inflamatória através dos ensaios de contorção abdominal induzida por ácido acético, hipernocicepção induzida pela injeção intraplantar de formalina, e teste da pressão crescente na pata, a determinação da migração de neutrófilos para a cavidade peritoneal e avaliação da permeabilidade vascular por azul de Evans, detecção de citocinas por imunofluorescência, ensaio da atividade de mieloperoxidase e análise de expressão proteica mesentérica por Western Blot, apresentando inibição da produção de citocinas pró-inflamatórias e inibição do recrutamento de neutrófilos. A fim de encontrar o composto responsável pela ação anti-inflamatória de M. hostilis foi sintetizada a isossacuranetina e comparada à ação da sacuranetina isolada que apresentou melhor atividade, embora ainda não seja possível associá-la a atividade do extrato.
This paper describes the phytochemical study and the evaluation of antioxidant, antimicrobial, anti-inflammatory and antinociceptive activities of the extract and isolates of Mimosa hostilis Benth which is a medicinal plant used to treat cough and wound healing. The genus Mimosa, belongs to the Leguminoseae family and the Mimosaceae (Mimosoideae) subfamily which has about 500 species, sources of special metabolites, such as alkaloids, phenolic compounds, terpenoids, saponins, carotenoids and, mainly flavonoids. The ethanolic extracts of the bark, leaves and branches of M. hostilis, popularly known as Jurema-preta, collected in the National Forest Contendas do Sincorá, located in the semiarid region of Bahia were analyzed by GC- MS. These analyses permitted to identify the presence of carbohydrates as the major compounds besides fatty acids, phenolics and terpenes. From dichlorometanic fraction of leaves, it was isolated the ethyl 3,4,5-trihydroxybenzoate (FDF1) and 4-hydroxybenzoic acid (FDF2) and flavonoids 5,4'-dihydroxy-7-metoxiflavanona (M1), 5,4'-dihydroxy-7- methoxyflavone (M2), 5,6,4'-trihydroxy-7-methoxyflavone (M3), 5,4'-dihydroxy-7,8- dimethoxy (M4) , 5,7,4 '-trihydroxy-3-methoxyflavone (M5), 5,7,4'-trihydroxy-6- metoxiflavonol (M6), 5,6-dihydroxy-7,4'- dimetoxiflavonol (M7) and 5-hydroxy-7,8,4'- trimetoxiflavonol (M8). These compounds were identified by 1H and 13C NMR spectroscopic analysis, UV and MS, 5-hydroxy-7,8,4'-trimetoxiflavonol (M8) showed inhibitory activity of AChE for treatment of Alzheimer's disease. The ethanolic extracts showed antioxidant activity similar to those obtained by the controls BHT and α-tocopherol, results obtained by DPPH assay with emphasis on the extract of the bark, which has a higher total phenolic content analyzed by Folin-Ciocalteu methodology. The extracts were also evaluated by testing β-carotene/ linoleic acid system presenting themselves as good sequestrants of free radicals, as well as controls and were classified as good blockers of oxidative reactions. The ethanolic extracts of bark and leaves were tested for MIC and MBC and showed strong inhibitory activity for microorganisms Streptococcus mutans UA159, Streptococcus mutans Ingbritt 1600, Staphylococcus aureus ATCC 25923, and the extract from the bark showed activity for Escherichia coli ATCC 25922 and leaf extract to Pseudomonas aeruginosa ATCC 10145 also presenting some bactericidal activity. To mutans streptococci , was also performed the CIMA test to evaluate the antiplaque activity, showing strong inhibition, especially observed by the leaf extract, which was used to evaluate the inhibition of biofilm formation of S. mutans UA159 and decreased viability of bacteria and biofilm dry weight compared to chlorhexidine control by the topical treatment of the extract. The extract of bark were also evaluated in vivo for the anti-inflammatory and antinociceptive activity by the writhing test induced by acetic acid, hypernociception induced by intraplantar injection of formalin, and testing the increasing pressure on the paw, the determination of neutrophils migration into the peritoneal cavity and evaluation of vascular permeability by Evans blue, Cytokine detection by immunofluorescence assay, myeloperoxidase activity and mesenteric protein expression analysis by Western blot, showing activity probably by inhibition of proinflammatory cytokine and inhibition of neutrophils migration. In order to find the compound responsible for the anti-inflammatory activity of M. hostilis, isossacuranetin was synthesized and compared to the action of the isolated sacuranetin that showed better activity, although it is not possible to associate it with the activity of the extract.
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Ricardo, kelly Fabiane Santos. « Efeitos hipolipidêmico e sinérgico de flavonóides, corantes naturais e fármacos ». Universidade Federal de Viçosa, 1998. http://www.locus.ufv.br/handle/123456789/7655.
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Fundação de Amparo à Pesquisa do Estado de Minas Gerais
As propriedades biologicas dos flavonoides estao sendo muito exploradas, por possulrem aplicaooes em diversas areas, tais como: Bioqulmica, Quimica, lndflstria de Alimentos, Ecologia, Entomologia, Fitopatologia, Fisiologia Vegetal e Microbiologia. Alguns cientistas tém concentrado suas pesquisas na area médica, visando a uma infinidade de acées nos diversos sistemas, sejam eles cardiovasculares, imunolégioo, reprodutor, hormonal ou muscular. Desenvolveram-se quatro experimentos, tendo sido as substancias administradas por via intraperitoneal ou via oral a ratos machos Wistar hiperlipidémicos (induzida por triton), usando-se os flavonoides (morina, quercetina, naringenina, rutina); e 05 medicamentos (acido nicotinico, colestiramina) e os oorantes naturais (antocianina, Monascus) na dose 5,0 mg/kg de peso corporal. No experimento 5, as substancias foram administradas por via oral, na raoao, nas seguintes doses: colestiramina, 10 mg; flavonoides, 30 mg; hiperlipidemia, induzida por colesterol, 1%; e acido célico, 0,1%. Foram determinados colesterol, colesterol-HDL e triacilglicerois em todos os experimentos. Nos experimentos em que se administraram duas doses das substancias, por via intraperitoneal, encontraram-se melhores efeitos, quando comparados aos experimentos em que foi administrada uma dose das substéncias pela mesma via. Quando os flavonéides foram administrados isoladamente ou associados a corantes naturais, foram observados efeitos hipolipidémico e sinérgico. No experimento em que a, hiperlipidemia foi induzida por dieta, contendo colesterol e acido célico, os flavonéides, a colestiramina e as suas associagées foram administrados por via oral (misturados a ragao), constatando-se efeito hipolipidémico e sinérgico em todos os tratamentos. Por fim, nas analises de figado dos mesmos animais, onde foi determinado o colesterol, constatou-se um decréscimo acentuado Para os experimentos realizados. Concluiu-se, dessa forma, que as substéncias testadas (flavonéides, medicamentos e corantes) possuem efeito hipolipidémico e sinérgico, quando administradas por via intraperitoneal e oral em ratos machos Wistar.
The biological properties of flavonoids have been largely explored for they can be applied on several areas such as: Biochemistry, Chemistry, Food Industry, Ecology, Entomology, Phytopathology, Vegetal Physiology and Microbiology. Some scientists’ researches have been focused on medical area involving an infinity of actions upon several systems (cardiovascular, immune, reproducer, hormone or muscular). Four experiments were carried out with substances administered by either intraperitoneal or oral via to male hyperlipidemic Wistar mice (triton-induced), and the flavonoids (morin, Cluercetin, naringenin, rutin), medicines (nicotinic acid, cholestyramine) and natural dyes (anthocyanin, Monascus) being added at 5.0 mg/kg of body weight. In experiment 5, the substances were orally administered through ration at the following doses: 10 mg of cholestyramine; 30 mg of flavonoids; hyperlipidemy induced by 1% cholesterol; and 0.1% cholic acid. Cholesterol, HDL-cholesterol and triacylglycerols were determined for all experiments. The experiments in which two doses of each substance were administered through intraperitoneal via showed better effects when compared to those in which just one dose of each substance was added through the same via. Synergic and hypolipidemic effects were observed when administering the flavonoids isolated or associated to natural dyes. In the experiment where hyperlipidemy was induced by diet containing both cholesterol and cholic acid, the flavonoids, cholestyramine and their associations were administered through oral via (mixed with ration), with synergic and hypolipidemic effects being observed for all treatments. The results from animals’ liver analyses showed a pronounced decrease in cholesterol for all experiments. So, it was concluded that the tested substances (flavonoids, medicines and dyes) have both synergic and hypolipidemic effects when administered by intraperitoneal and oral via to male Wistar mice.
Dissertação antiga
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Martínez, Pérez Carlos. « Evaluation of the antitumour activity of novel flavonoids on pre-clinical models of breast and ovarian cancer ». Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/25410.
Texte intégralRésumé :
New drugs are needed for better cancer management. Clinical trials are currently underway to assess the use of flavonoids (natural polyphenols) as anticancer agents. Among them, myricetin has been shown to induce cell cycle arrest and apoptosis in pre-clinical cancer models. We hypothesised that myricetin-derived novel flavonoids designed to enhance this natural potential and improve on the drug-likeness limitations of myricetin might have increased potential for their application in the management of breast and ovarian cancer. The effect of a library of novel flavonoids was screened on 3 panels of breast and ovarian cancer cell lines, representing different molecular subtypes and phenotypes, to assess their potency. The second-generation bi-methoxylated analogue AO-1530-OMe (Oncamex) was identified as the most effective candidate in the library, with sub-micromolar concentrations exerting a strong antiproliferative effect across almost all models studied. Results suggested that changes in the hydroxylation profile, the addition of methoxylations and a decyl alkyl chain were some of the structure-activity relationships contributing to this improved efficacy. Plate assays showed 8 h treatment with Oncamex reduced cell viability and induced cytotoxicity and apoptosis, concomitant with caspase activation and PARP cleavage. Pre-incubation with an antioxidant partially blocked these effects, suggesting the possible involvement of ROS modulation in the mechanism of action of Oncamex. Fluorescence microscopy reported the quick and stable delivery of Oncamex to the mitochondria. Fluorescent probes showed that Oncamex can induce mitochondrial superoxide production at concentrations associated with its antiproliferative effects. Study of the electrochemical properties of Oncamex by cyclic voltammetry supported this. Differential gene expression analysis following a microarray experiment showed Oncamex induces changes in the expression of genes controlling cell cycle and apoptosis. Together with previous results, the findings from this analysis led to the postulation of a model for the mechanism of action of Oncamex: due to its enhanced reactivity and mitochondrial targeting, Oncamex can generate mitochondrial superoxide, leading to mitochondrial dysfunction, membrane permeabilisation and the activation of the JNK pathway and the transcription factor FOXO3, which together contribute to the induction of intrinsic apoptosis and the inhibition of proliferation. Further proliferation assays on cell culture models also reported enhanced effect of Oncamex when administered in combination with paclitaxel and TRAIL. These improved responses were observed in breast and ovarian cancer models, including cells lines characterised by their treatment-resistant phenotype. Cotreatment with Oncamex also improved the effect of tamoxifen on anti-oestrogen resistant LCC9 breast cancer cells. Results from preliminary in vivo studies in mice implanted with the MDA-MB-231 breast cancer xenograft were consistent with an antiproliferative effect of Oncamex (25mg/kg/day) in vivo, as treatment inhibited tumour growth and reduced the expression of the marker of proliferation Ki-67 without signs of systemic toxicity. Tissues from this experiment also allowed for preliminary in vivo validation of the proposed mechanism of action of Oncamex by immunohistochemistry. The in vivo cytostatic effect of Oncamex was confirmed in a second in vivo experiment, which also investigated the effect of Oncamex at higher doses or in combination with paclitaxel. In conclusion, the novel flavonoid Oncamex has shown a promising antiproliferative effect in pre-clinical models of breast and ovarian cancer, including models of treatment-resistant cancers. Preliminary in vivo studies have demonstrated a partial recapitulation of the effect of Oncamex. A mechanistic model has been proposed by which Oncamex induces intrinsic apoptosis through its redox reactivity and mitochondrial targeting. These results support the potential of this prototypic candidate, although possible work in the structure and formulation of this candidate and further study and validation of its mechanism of action is needed for its continued development as an anticancer agent.
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Juneja, Kashmir Singh. « Tyrosinase-like activity of several Alzheimer's disease related and model peptides and their inhibition by natural antioxidants ». [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001838.
Texte intégral
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Oliveira, Irvila Ricarte de. « Study of variability chemistry and pharmacological potential by specimens of Senna from Northeast ». Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=15344.
Texte intégralRésumé :
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoEste trabalho relata o perfil quÃmico e farmacolÃgico de quatro espÃcies do gÃnero Senna Mill. â Senna gardneri, Senna georgica, Senna splendida e Senna macranthera var. pudibunda. Este estudo permitiu identificar 38 compostos diferentes de vÃrias classes, com destaque para os flavonoides, dentre os quais: galocatequina, epigalocatequina, (2R*,3S*,4S*,2ââR*,3ââS*)-guibourtinidol-(48)-catequina, quercetina glicoarabinose, taxifolina, isoramnetina, procianidina B1, miricetina e di-hidromiricetina. Todos esses compostos foram relatados pela primeira vez em espÃcies de Senna. AnÃlise quantitativa por cromatografia lÃquida de alta eficiÃncia (CLAE-DAD-ESI-MS) do material em estudo indicou o (E)- 3,3â,5,5â- tetra-hidroxi 4-metoxi estilbeno como majoritÃrio nas raÃzes de Senna georgica (6,14 g/Kg), S. gardneri (5,36 g/Kg) e S. splendida (19,23 g/kg). Nas raÃzes e no caule de S. macranthera var. pudibunda, a catequina foi o composto majoritÃrio com teores de 0,87 g/kg e 1,32g/kg, respectivamente. Nas folhas, a quercetina glicoarabinose foi o composto majoritÃrio nas espÃcies de S. gardineri (11,99g/kg) e S. splendida (3,24 g/kg), e a epigalocatequina, nas folhas de S. macranthera var. pudibunda (1,68 g/kg). O fracionamento cromatogrÃfico (CLAE) resultou na obtenÃÃo de seis compostos puros: (E)- 3, 3â, 5,5â- tetra-hidroxi 4-metoxi estilbeno, catequina, rutina, quercitrina, quercetina e (2R*,3S*,4S*,2'R*,3'S*)-guibourtinidol-(48)-catequina. A atividade antioxidante dos extratos e compostos puros foi analisada atravÃs das tÃcnicas de DHBA, DPPH, FRAP e ORAC, com resultados promissores para todas as amostras investigadas. Os extratos de S. georgica, S. macranthera var. pudibunda e S. gardneri apresentaram atividade anticolinesterÃsica e, para os ensaios enzimÃticos de inibiÃÃo da enzima conversora da angiotensina I, as folhas e raÃzes de S. gardneri apresentaram os melhores resultados. Os extratos das espÃcies de Senna nÃo apresentaram toxidade frente à Artemia salina e nem potencial leishmanicida. O estudo confirmou o potencial como fonte de compostos bioativos para as espÃcies de Senna estudadas.
This Thesis describes the chemical and pharmacologic profile of four species of the genus Senna Mill. Namely Senna gardneri, Senna georgica, Senna splendida and Senna macranthera var. pudibunda. In this study 38 different polyphenolic compounds of various classes, especially flavonoids were identified by HPLC-DAD-ESI-MS and NMR where possible. The flavonoids were identified as (+)-gallocatechin, (-)-epigallocatechin, 2R,3S,4S,2ââR,3ââS)-guibourtinidol-(48)-catechin, quercetin glucoarabinoside, taxifolin, isorhamnetin, procyanidin B1, myricetin and dihydromyricetin. All these compounds are reported for the first time in species of Senna. Quantitative analysis by HPLC showed that, in the material under study (E)-3, 3', 5, 5'-tetrahydroxy-4-methoxy stilbene was the major compound in the roots of Senna georgica (6.14 g/kg), Senna gardneri (5.36 g/kg) and Senna splendida (19.23 g/kg). In the roots and bark of Senna macranthera var. pudibunda, the flavonoid (+)-catechin was the major compound, with levels at 0.87 g/kg and 1.32g/kg, respectively. In the leaves of Senna gardineri and Senna splendida, the major compound was quercetin glucoarabinoside at 12.10 g/kg and 3.241g/kg respectively, and in the leaves of Senna macranthera var. pudibunda (-)-epigallocatechin at 1.68 g/kg. Chromatographic fractionation by semi-preparative HPLC resulted in the purification of six compounds: (E)-3, 3', 5, 5'-tetrahydroxy-4-methoxy stilbene, (+)-catechin, rutin, quercitrin, quercetin and (2R*,3S*,4S*,2''R*,3''S*)- guibourtinidol-(48)-catechin. The antioxidant capacity of the extracts and pure compounds was analyzed by the DPPH, FRAP, ORAC, and HPLC-based HX/XO assays, with promising results for all samples investigated. Extracts of Senna georgica, macranthera var. pudibunda and gardneri displayed anticholinesterase activity and, inhibition of angiotensin converting enzyme-I. Extracts of the leaves and roots of Senna gardneri showed the best results. No toxicity of the extracts in the brine shrimp and leishmanicidal assays was evident. This study confirmed the potential of Senna species as a valuable source of bioactive polyphenolic compounds, which may augment their use in traditional Brazilian medicine.
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Santos, Rauldenis Almeida Fonseca. « Estudo fitoquímico e avaliação biológica dos flavonoides isolados de clitoria fairchildiana R. A. Howard ». Instituto de Química, 2014. http://repositorio.ufba.br/ri/handle/ri/19139.
Texte intégralRésumé :
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A espécie Clitoria fairchildiana R. A. Howard., sinonímia Clitoria racemosa Benth., é popularmente conhecida como sombreiro e utilizada na arborização urbana, apresentando diversos relatos de isolamento de flavonoides com atividades antioxidante, citotóxica, anti- inflamatória e alelopática. O presente trabalho descreve o estudo químico das raízes e pétalas da Clitoria fairchildiana, permitindo o isolamento dos flavonoides clitoriacetal (2), 6- desoxiclitoriacetal (3), stemonal (4), stemonona (5), canferol (6), quercetina (7), vitexina (8), astragalina (9) e dos fitoesteroides β-sitosterol (1) e estigmasterol (1a), além da identificação por CG-EM de ácidos graxos e fitol. Também foram realizados ensaios biológicos, dos extratos e substâncias isoladas, tais como de atividade frente Artemia salina, antioxidante e de inibição da enzima acetilcolinesterase. As substâncias clitoriacetal (2) e 6-desoxiclitoriacetal (3) apresentaram moderada atividade frente Artemia salina, com valores de DL50=515,3μg.mL-1 e DL50=260,5μg.mL-1, respectivamente. Enquanto que a astragalina (9) apresentou uma maior atividade (DL50=77,1μg.mL-1). No teste antioxidante de sequestro do radical livre DPPH, a quercetina (6) e o canferol (5) apresentaram as maiores atividades antioxidante. Diferentes extratos da espécie vegetal foram analisados por CLAE-DAD, determinando que os rotenoides clitoriacetal (2) e o 6-desoxiclitoriacetal (3), são encontrados em maior quantidade nas raízes, contudo não são encontrados nas folhas e pétalas da espécie. As substâncias isoladas foram identificadas por métodos espectrométricos (IV, UV/Vis, EM, RMN de 1H e RMN de 13C) e por comparação com dados da literatura. Dessa forma, este trabalho contribui para a taxonomia da espécie Clitoria fairchildiana, descrevendo o primeiro estudo fitoquímico das pétalas dessa espécie, além de relatar o primeiro isolamento da stemonona (5), obtido anteriormente apenas por modificação estrutural.
The species Clitoria fairchildiana R. A. Howard., Synonymy Clitoria racemosa Benth., is popularly known as sombrero and used in urban forestry, with several reports of isolation of flavonoids with antioxidant, cytotoxic, anti-inflammatory and allelopathic activities. This work describes the chemical study of the roots and petals of Clitoria fairchildiana, allowing the isolation of flavonoids clitoriacetal (2), 6-deoxyclitoriacetal (3), stemonal (4), stemonone (5), kaempferol (6), quercetin (7), vitexin (8), astragalina (9) and fitoesteroides β-sitosterol (1) and stigmasterol (1a), besides the identification by GC-MS of fatty acids and phytol. Biological assays of the extracts and isolated substances, such as activity against, Brine shrimp, antioxidant and inhibition of acetylcholinesterase were also conducted. Biological assays of extracts and pure compounds such as facing activity Brine shrimp, antioxidant and inhibiting acetylcholinesterase enzyme were also performed. The substances clitoriacetal (2) and 6-deoxyclitoriacetal (3) showed moderate activity against Brine shrimp, with values LD50=515.3 μg.mL-1 and LD50=260.5 μg.mL-1, respectively. While astragalina (9) showed increased activity (LD50=77.1 μg.mL-1). In antioxidant test kidnapping of free radical DPPH, quercetin (6) and kaempferol (5) showed the highest antioxidant activities. Different extracts of the plant species were analyzed by HPLC-DAD, determining that the rotenoids clitoriacetal (2) and 6-deoxyclitoriacetal (3), are found in greater amounts in the roots, but are not found in the leaves and petals of the species. The compounds were identified by spectroscopic methods (IR, UV/Vis, MS, 1H NMR and 13C NMR) and by comparison with the literature data. Thus, this work contributes to the taxonomy of species Clitoria fairchildiana, describing the first phytochemical study of the petals of this species, in addition to reporting the first isolation of stemonone (5), obtained previously only by structural modification.
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Vejrostová, Petra. « Studium směsných přírodních antimikrobiálních preparátů a možnosti jejich stabilizace ». Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2016. http://www.nusl.cz/ntk/nusl-240734.
Texte intégralRésumé :
Present diploma thesis is focused on natural antimicrobial substances. The aim of the experimental part of thesis was testing of antimicrobial activity of selected natural substances in free and encapsulated forms, preparation of particles and monitoring of their long-term stability. Various teas extracts (aqueous, ethanoic and DMSO) and aqueous herbs extracts were used as plant antimicrobial substances. Liposomes and chitosan particles with encapsulated aqueous teas extracts were prepared by ultrasonication. Encapsulation efficiency, size, stability and antioxidant activity for all particles were specified. Consequently, within a two months period, long-term stability for these particles was monitored. Spectrophotometric method for determining total polyphenols was used for evaluating encapsulation efficiency as well as for monitoring of long-term stability. The DLS method was used for determination of size and stability of particles. Antioxidation activity was monitored by using spectrophotometric method using ABTS. For testing antimicrobial activity of various types of teas, herbs extracts and their mixtures and combianitons with lysozyme and antibiotics, broth dilution methods were used while using both Gram positive and Gram negative bacterial test strains. Antimicrobial activity of prepared particles was also monitored, the antimicrobial activity was especially significant with the chitosan particles. Suitable combinations of natural substances whatever with antimicrobial or antioxidation effect either in free or encapsulated form could be used for applications for example in cosmetics industry, food processing or in medicine.
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Yamaguchi, Lydia Fumiko. « Potencial dos biflavonóides de Araucaria angustifolia (Bert.) O. Kuntze como antioxidantes e fotoprotetores ». Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/46/46131/tde-12072016-115252/.
Texte intégralRésumé :
A Araucaria angustifolia é uma conífera endêmica das regiões sul e sudeste do Brasil sendo considerada uma espécie em extinção devido ao extenso extrativismo madeireiro. Atualmente, existem inúmeros projetos visando o reflorestamento e o uso sustentável deste pinheiro. Em vista destes pontos, o estudo das propriedades dos componentes das folhas com o intuito da utilização destes com fins comerciais tornou-se de extrema importância. As suas folhas foram submetidas à extração com solventes e foram identificados seis biflavonóides majoritários, dentre estes a amentoflavona e a ginkgetina, que são apontados como agentes contra inflamações e artrites. A fração rica de biflavonóides (BFF) extraída da araucaria foi testada frente a sua atividade em proteger contra danos em biomoléculas provocadas por espécies reativas de oxigênio, capacidade em quelar metais e proteção contra raios UV. A capacidade do BFF em proteger contra danos provocados por espécies reativas de oxigênio foi comparado com compostos conhecidamente antioxidantes, como o α-tocoferol, Trolox®, quercetina, rutina e com padrões de biflavonóides, a amentoflavona e ginkgetina. O BFF demonstrou que possui uma constante de supressão do 1O2 (50 x 106 M-1s-1), superior ao da quercetina (9 x 106 M-1s-1) e foi o mais eficiente na proteção contra quebras de simples fita em DNA plasmidial, provocado por esta espécie reativa. Ainda em relação à proteção de DNA plasmidial o BFF foi capaz de proteger também contra estes danos provocados através da reação de Fenton, apesar de não demonstrar a mesma eficiência da quercetina que mostrou ser um potente protetor destes danos. O BFF protegeu contra lipoperoxidação em lipossomos de fosfatidilcolina induzida por raios UV e reação de Fenton. Em análises realizadas com espectrometria de massas foi observada a formação de complexos destes biflavonóides com íons metálicos como ferro, cobre e alumínio que possuem um papel importante na formação de radicais livres. Em relação à capacidade fotoprotetora do BFF, este inibiu a formação de dímeros de pirimidina que são apontados como causadores de câncer de pele induzidos, principalmente por radiação UV-B. Esta ação protetora foi superior àquela conferida ao p-metoxicinamato de octila, um conhecido fotoprotetor. Com o intuito de permitir a solubilização do BFF em soluções aquosas e assim, avaliar a ação do BFF em células, incorporou-se o BFF em ciclodextrina. Essa inclusão favoreceu a incorporação de BFF em células CV1-P na concentração aproximada de 0,4 µg/ml após 24 horas de incubação. Essa concentração incorporada não demonstrou ser tóxica para as células no teste com MTT. Assim, o BFF tem despertado grande interesse em relação ao seu potencial na utilização nas mais variadas áreas como cosmética, alimentos e fitoterápicos.Araucaria angustifolia is an endemic conifer in southern and southeastern Brazil endangered due the extensive loggings. Nowadays, there are several projects aiming the recovering of forest and the sustainable use of their products. Its needles contain six major amentoflavone-type biflavonoids, including amentoflavone, ginkgetin and tetra-O-methylamentoflavone, all reported to possess a variety of biological activities such as anti-inflammatory and antiarthritic activities. The organic fraction rich in biflavonoids (BFF) extracted from Araucaria was evaluated regarding its activity to protect against damage to biomolecules promoted by reactive oxygen species, its capacity to chelate ion metals and protection it affords against UV radiation. The ability of the BFF prevent oxidative damages was compared to antioxidants compounds, such as, α-tocopherol, Trolox®, quercetin, rutin and with standards of biflavonoids amentoflavone and ginkgetin. The BFF showed a higher 1O2 quenching rate (50 x 106 M-1s-1) than individual quercetin (9 x 106 M-1s-1). Accordingly, BFF was shown to strongly inhibit plasmid DNA single strand break (ssb) induced by 1O2 generated by NDPO2. On the other hand, BFF did not protect plasmid DNA against ssb triggered by the Fenton reaction as effectively as quercetin and rutin. BFF, quercetin and rutin were able to protect liposomes against peroxidative degradation caused by UV-irradiation. Since there is considerable evidence relating oxygen species with UV phospholipid degradation, the protective effect of quercetin and rutin is likely to result from their well-known scavenging activity against hydroxyl and peroxyl radicals and superoxide anion radicals. Using electrospray ionization mass spectrometry, metal (Fe3+, Cu2+ and Al3+) biflavonoids complexes were also detected and characterized. The sunlight UV region is believed to be largely responsible for the greatest damage to the skin including indution of the pirimidine dimers formation suggested to be implicated in skin cancer. BFF was able to diminish the formation of this photoproduct more efficiently tham octyl methoxycinnamate. Solubilization of BFF in aqueous solutions was performed using cyclodextrin, which allowed the incorporation of 0,4 g/ml of biflavonoids in CV1-P cells after 24 hours. In this conditions the BFF was not cytotoxic to CV1-P evaluated by the MTT assay.Altogether, these properties point BFF as an excellent candidate for successful employment as antioxidant compound in several systems.
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Maoela, Manki Sarah. « Spectroelectrochemical determination of the antioxidant properties of carpobrotus mellei and carpobrotus quadrifidus natural products ». Thesis, University of the Western Cape, 2009. http://hdl.handle.net/11394/3299.
Texte intégralRésumé :
Philosophiae Doctor - PhDSouth African Carpobrotus species have been found to contain hydrolysable tannins,various flavonoids e.g. rutin and hyperoside, phytosterols and aromatic acids which have a diverse range of pharmacological properties including antimicrobial and, antioxidant activities. The main aim of the thesis was to determine the natural products in C. mellei and C. quadrifidus using chromatographic techniques and electrochemical analysis. The antioxidant activity of both Carpobrotus species was determined by using a superoxide dismutase (SOD) biosensor. ESI-LC-MS was used to separate and determine flavonoids in C. mellei and C. quadrifidus. 8 flavonoid compounds: catechin, epicatechin, epicatechin-epicatechin, coumarylquinic acid, isorhamnetin, quercetin-hexose (hyperoside), rutin and myricetin-deoxyhexose were identified. Cyclic and square wave voltammetry were used to detect flavonoids from C. mellei and C. quadrifidus. Catechin was detected in the ethyl acetate extract of C. mellei and C. quadrifidus. The oxidation potential of the plant extracts were observed at +150.6 mV to +1072.6 mV. The oxidation mechanism proceeds in sequential steps, related to the catechol moiety, -OH groups in C ring and the resorcinol group. The oxidation process of the catechol moiety involves a two electron - two proton reversible reaction and forms o-quinone. This occurs first at low potential and is a reversible reaction. The hydroxyl group in the C ring and resorcinol group oxidise there after and undergo an irreversible reaction. UV-vis and FTIR spectroscopy were used to confirm the presence of catechin in the ethyl acetate extract of both plants.UV-visible spectroelectrochemistry confirmed the oxidation process of catechin at constant potential. Since C. mellei and C. quadrifidus were confirmed to contain flavonoids by ESI-LC-MS and electrochemical analysis, the antioxidant activity was further investigated using a SOD biosensor. The superoxide dismutase (SOD) enzyme was immobilised with 1% Nafion on a platinum electrode. Detection limit and sensitivity of the SOD biosensor were found to be 0.03918 μmol L-1 and 1.44 μA(μmol L-1)-1, respectively. The results showed that C. mellei and C. quadrifidus have antioxidant activity, with relative antioxidant capacity (RAC) of 24% and 42%, respectively. May 2009
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Pan, Ende. « Searching for Anticancer Agents and Antimalarial Agents from Madagascar ». Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/77260.
Texte intégralRésumé :
In our continuing search for biologically active natural products from Madagascar as part of an International Cooperative Biodiversity Group (ICBG) program, a total of four antiproliferative extracts were studied, leading to the isolation of twelve novel compounds with antiproliferative activity against the A2780 human ovarian cancer line, and one extract with antimalarial activities was studied, which led to the isolation of five new natural products with antimalarial activities against the Dd2 and HB3 malarial parasites.
The plants and their metabolites are discussed in the following order: one new xanthone and two known guttiferones from Symphonia tanalensis Jum. & H. Perrier (Clusiaceae); four new diphenyl propanes and one new cyclohepta-dibenzofuran skeleton from Bussea sakalava (Fabaceae); four new cardiac glycosides from Leptadenia madagascariensis Decne. (Apocynaceae); two new and four known alkaloids from Ambavia gerrardii (Baill.) Le Thomas (Annonaceae); five new sesquiterpene lactones from Polycline proteiformis Humbert (Asteraceae).
The structures of all compounds were determined by analysis of their mass spectrometric, 1D and 2D NMR, UV and IR spectroscopic and optical rotation data. Other than structure elucidation, this dissertation also involve bioactivity evaluation of all the isolates, synthesis of two interesting alkaloids, as well as a proposal for the possible biosynthetic pathway of the new cyclohepta-dibenzofuran skeleton.Ph. D.