Dissertations / Theses: 'Flavonoids'

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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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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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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Roedig-Penman, Andrea. "Flavonoids as antioxidants." Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363806.

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Caruso, Ícaro Putinhon [UNESP]. "Estudo da interação entre flavonóides e a albumina do soro humano." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/87502.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Os flavonóides são uma grande classe de polifenóis ocorrendo de forma natural amplamente distribuídos nas plantas, essas moléculas exibem algumas atividades farmacológicas importantes como anti-inflamatória, antioxidante, anticancerígena e antibacteriana. A interação entre os flavonóides Rutina (Ru) e Guaijaverina (Gua) e a Albumina do Soro Humano (HSA) em pH 7,0 fisiológico foi investigado usando a técnica de espectroscopia de fluorescência de estado estacionário, cálculo ab initio e de modelagem molecular. A partir da supressão de fluorescência da HSA pelos flavonóides, a constante de supressão de Stern-Volmer ( SVK ) e sua forma modificada ( aK ) foram calculadas em 298, 303 e 308 K, como também os parâmetros termodinâmicos correspondentes H , G e S , para cada flavonóide. A análise do equilíbrio de ligação foi utilizada para determinar os valores do número de sítios de ligação ( n ) e a constante de ligação ( bK ) para a Rutina e a Guaijaverina em 298, 303 e 308 K. A distância média entre o doador (HSA-214Trp ) e o aceitador (Ru e Gua) foi estimada de acordo com a teoria de transferência de energia ressonante fluorescente. A otimização geométrica dos flavonóides Rutina e Guaijaverina foi realizada nos seus estados fundamentais usando o funcional DFT/B3LYP ab initio com um conjunto de bases 6-31G(d,p) utilizado nos cálculos. O cálculo de modelagem molecular indica que os flavonóides se localizam no sítio I da HSA, dentro do bolso hidrofóbico do subdomínio IIA. Os resultados teóricos obtidos pela modelagem molecular corroboram com os dados de espectroscopia de fluorescência
Flavonoids are a large class of naturally occurring polyphenols widely distributed in plants, these molecules exhibit some important pharmacological activities like anti-inflammatory, antioxidant, anticancer, and antibacterial. The interaction between Rutina and Guaijaverin flavonoids and Human Serum Albumin (HSA) at physiological pH 7.0 was investigated by using the technique of fluorescence spectroscopy, ab initio and molecular modeling calculation. From the fluorescence quenching of the HSA by flavonoids, the Stern-Volmer quenching constant ( SVK ) and its modified form ( aK ) were calculated at 298 , 303 and K308 , as well as the corresponding thermodynamic parameters H , G and S , for each flavonoid. Analysis of binding equilibria was utilized to determine the number of binding sites ( n ) and binding constants ( bK ) values for Rutin and Guaijaverin at 298 , 303 and K308 . The average distance between donor (HSA-214Trp ) e acceptor (Ru and Gua) was estimated according to the theory of fluorescence resonance energy transfer. The geometry optimization of Rutin and Guaijaverin flavonoids was performed in its ground state by using ab initio DFT/B3LYP functional with a 6-31G(d,p) basis set applied in calculations. Molecular modeling calculation indicated that the flavonoids are located in site I of HSA, within the hydrophobic pocket of the subdomain IIA. The theoretical results obtained by molecular modeling are corroborated by the fluorescence spectroscopy data

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Pereira, Gabriela Sterle. "Ação inibitória dos flavonoides quercetina e rutina sobre a ativação de neutrófilos humanos /." Assis, 2017. http://hdl.handle.net/11449/150482.

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Orientadora: Karina Alves de Toledo
Banca: Luis Octávio Regasini
Banca: Flávia Aparecida Paina Brasil
Resumo: Rutina e Quercetina são flavonoides encontrados em diversos alimentos, incluindo aqueles indicados como complemento no tratamento de doenças inflamatórias. Durante o processo inflamatório, neutrófilos são as primeiras células a serem recrutadas por estarem diretamente relacionadas à ativação e resolução destes processos. Assim, frequentemente estas células são alvos para novos compostos anti-inflamatórios. A descrição da atividade anti-inflamatória de rutina e quercetina se estende para vários ativadores das vias clássicas dos neutrófilos. O estudo quanto aos compostos forbol ésteres, como PMA (phorbol myristate acetate), que ativam de maneira específica a sinalização da proteína quinase C, ainda são escassos.O objetivo deste trabalho foi analisar a atividade anti-inflamatória de rutina e quercetina sobre neutrófilos ativados por PMA. Para tanto, foram analisadas etapas importantes do processo inflamatório mediadas pelos neutrófilos: adesão, desgranulação, e liberação das NETs (Neutrophil Extracelular Traps). Nossos resultados demonstraram que, ativação de neutrófilos por PMA: (i) rutina e quercetina não inibem a adesão dos neutrófilos, (ii) quercetina inibe a desgranulção, (iii) ambos inibem a atividade da mieloperoxidase (MPO), assim como (iv) inibem a liberação das NETs na ausência de morte celular. Análises de docking molecular sugerem que tais eventos podem estar relacionados à geração de complexos quercetina/MPO e rutina/elastase
Abstract: Rutin and Quercetin are flavonoids found in several foods, including those indicated as a supplement in the inflammatory treatment diseases. During the inflammatory process, neutrophils are the first cells to be recruited. They are directly related to the activation and resolution of these processes. Thus, these cells often target new antiinflammatory compounds. The description of the anti-inflammatory activity of rutin and quercetin extends to several activators of classical neutrophil pathways. Studies involving forbol esters compounds, as PMA ((phorbol myristate acetate), which activate in a specific manner the protein kinase signalling, it is still poor. The aim of this study was to analyze the anti-inflammatory activity of rutin and quercetin on PMAactivated neutrophils. For this, important steps of the inflammatory process mediated by neutrophils were analyzed: adhesion, degranulation, and release of NETs (Neutrophil Extracelular Traps). Our results demonstrated that neutrophil activation by PMA: (i) rutin and quercetin did not inhibit neutrophil adhesion, (ii) quercetin inhibited degranulation, (iii) both inhibited myeloperoxidase activity (MPO), as well as (iv) both Inhibit the release of NETs in the absence of cell death. Molecular docking analyzes suggest that such events may be related to the generation of quercetin/MPO and rutin/elastase complexes
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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.

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Orientador: Vanderlan da Silva Bolzani
Banca: 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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Alalwan, Tariq Abdulkarim Ebrahim. "Absorption of Dietary Flavonoids." Thesis, University of Leeds, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491922.

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Flavonoids represent a major class of plant polyphenols that are distributed ubiquitously in the human diet. Interest in the possible health-promoting effects of flavonoids has increased due to their various bioactive properties, as demonstrated in several in vitro and in vivo studies. Knowledge about flavonoid absorption and bioavailability is essential in order to fully understand their potential health benefits. This thesis was concerned with the uptake and absorption of dietary flavonoids in humans, with an emphasis on the effect of the chemical form of the flavonoid (as a product of processing) and the effect of food matrix. The first study investigated the flavonol content in different varieties of commerciallygrown tomatoes and widely consumed tomato-based food products. It was shown that the levels of rutin varied considerably between different cultivars and food-based products, with the highest levels found in cherry tomatoes. Furthermore, cellulase -Blf h-=-y_d_ro---'l~~is_of rut~~_:v.~~_ shown to be a viable alternative for the release ~f queLc~~~~__ aglycone. The second study was aimed to investigate the absorption and bioavailability of dietary quercetin glycosides and its aglycone from a food-based system (non-supplement) in humans by implementing urinary time-course analysis. Ingested quercetin glycosides resulted in an observed earlier appearance of quercetin conjugates in urine then when quercetin aglycone was ingested (1 h compared to 2 h). Significantly more quercetin was absorbed than the aglycone when present in a similar onion-based food matrix system (1.8% compared to 1.3%). Finally, a second human study was carried out to investigate the effect of dietary fat, 8.3% (w/w), on the bioavailability of quercetin present in onion-based foods as either quercetin glycosides or its aglycone. Absorption of quercetin in its glycosidic form was shown to be significantly higher than the aglycone form when co-ingested with fat (2.8% compared to 1.7%). The ingestion of quercetin with fat, compared with the study without fat, enhanced the bioavailability of quercetin glycosides and its aglycone by about 50 and 23%, respectively, which was significant for the quercetin glycoside meal only.

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Lisseter, S. G. "Studies of phenolic flavonoids." Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355739.

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Noroozi, Mostafa. "Antioxidant effects of flavonoids." Thesis, University of Glasgow, 1998. http://theses.gla.ac.uk/5901/.

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Flavonoids are polyphenolic compounds whose main dietary source are fruits and vegetables. Epidemiological evidence has suggested that dietary flavonoids may protect against heart disease but biological effects have not hitherto been demonstrated directly in humans and there was no consistent evidence about the absorption of flavonoids. The studies performed for this thesis aimed to test antioxidant properties of flavonoids using an in vitro system, ex vivo tests on human tissue (lymphocytes) and in a dietary intervention. The main conclusions of this thesis are: 1. There is a potent antioxidant action of dietary flavonoids demonstrated by the comet assay, of potential importance in protection against cardiovascular disease and cancer. 2. The antioxidant capacities of most major dietary flavonoids are greater than vitamin C. 3. Results from the comet assay and TEAC show reasonable agreement in ranking. 4. Antioxidant activities of free flavonoids are more than the conjugated flavonoids. 5. There was a strong positive correlation between the number of hydroxyl groups of flavonoids and the antioxidant activity. 6. Dietary flavonoids are absorbed and the fasting plasma concentration can be increased 12 fold by a simple and palatable food supplement. 7. Supplementation with onions, tomato ketchup and tea led to protection of lymphocytes against free radical damage (H2O2), a biological effect of potential medical importance possibly attributable to the absorption of dietary flavonoids. 8. Dietary flavonoids intake (and specifically quercetin) can be estimated with reasonable accuracy from 24 hour urinary flavonoid excretion or fasting plasma concentration. 9. The range of dietary flavonoid consumption in ten NIDDM patients was estimated at 20-80 mg/day from their normal diets. On the basis of results in this thesis, dietary difference within this range would influence tissue antioxidant status.

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Kavuru, Padmini. "Crystal engineering of flavonoids." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002463.

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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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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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

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Severi, Juliana Aparecida [UNESP]. "Uso sustentável da biodiversidade brasileira prospecção químico-farmacológica de plantas superiores: Guapira noxia (Nyctaginaceae)." Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/97016.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Universidade Estadual Paulista (UNESP)
Esse trabalho é parte do projeto temático BIOTA-FAPESP: “Uso Sustentável da Biodiversidade Brasileira: Prospecção Químico-Farmacológica de Plantas Superiores” e visa contribuir com a caracterização do Bioma-Cerrado do estado de São Paulo, investigando espécies brasileiras de interesse químico-medicinal. Dentre as espécies com particular interesse estão as do gênero Guapira (Nyctaginaceae), com informações etnofarmacológicas de uso para problemas estomacais. G. noxia é conhecida popularmente como “Maria-mole” ou “Capa-rosa” e tem ocorrência no cerrado brasileiro. Essa espécie é utilizada na medicina popular como antiúlcera. Apesar do uso popular, ainda não há informações sobre a composição química e ensaios farmacológicos desta espécie e que cuja caracterização está sendo descrita pela primeira vez. O extrato metanólico das folhas de G. noxia foi fracionado por técnicas cromatográficas convencionais (Permeação em gel, HPLC) e a as substâncias resultantes foram identificadas através de métodos espectroscópicos (RMN, IV, UV e EM). Esse trabalho levou à identificação de oito heterosídeos de flanovóides (com três e duas unidades de açúcares) derivados da quercetina, da isorhamnetina e do kaempferol, além da alantoína e de um ciclitol. Além disso, foi estabelecido o perfil cromatográfico do extrato metanólico, juntamente com a quantificação do teor de compostos fenólicos e de flavonóides totais, com vistas à sua completa caracterização química. O estudo farmacológico do extrato metanólico evidenciou principalmente as atividades antiúlcera, antimicrobiana e imunomodulatória. A presença dos flavonóides e demais compostos fenólicos pode justificar os efeitos biológicos atribuídos à espécie. Como conclusão, este estudo contribuiu para aprofundar o conhecimento químicofarmacológico sobre Guapira noxia, que ocorre no cerrado brasileiro.
This work is part of the BIOTA-FAPESP project “Sustaintable use of the Brazilian Biodiversity: Chemical and Pharmacological Prospection on Higher Plants”, which intents to contribute to improve the knowledge of the biome Cerrado of the State São Paulo, Brazil. Species from the Guapira (Nyctaginaceae) genus have special interest, since they are used in folk medicine as antiulcerogenic agent. G. noxia is known in folk medicine as “Maria-mole” or “Capa-rosa” and occurs naturally in the Brazilian cerrado, being used due to its antiulcerogenic propertie. Although the folk use, there is no data about chemical and pharmacological studies on this species. We describe here the first chemical and pharmacological characterization. The methanolic extract of G. noxia leaves was fractionated by chromatography techniques (GPC, HPLC) and the substances were identified by spectrometric methods (NMR, MS, IR, UV). This approach led to identification of eight heterosides (two and three glycosides) of flavonoids derived from quercetin, isorhamnetin and kaempferol, besides one allantoin and one cyclitol. Moreover, we have established the HPLC/UV/DAD chromatographic profile of this extract, as well as the spectrophotometric quantification of phenolic compounds and flavonoids. Pharmacological investigations showed antiulcerogenic, antimicrobial and immunomodulatory properties of the methanolic extract. The presence of flavonoids and phenolic compounds may probably explain the pharmacologicals effects of the polar extract of G. noxia and their use in folk medicine. In conclusion, this study contributed to improve the knowledge of the chemistry and pharmacological activities of Guapira noxia, an species that occurs in the Brazilian cerrado.

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12

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.

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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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Uliana, Carolina Venturini [UNESP]. "Estudos da lesão ao DNA por corantes têxteis e da capacidade protetora de flavonóides empregando biossensor eletroquímico: Carolina Venturini Uliana. -." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/105701.

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A molécula do DNA pode ser modificada por substâncias eletrofílicas, tanto de origem exógena quanto endógena. As lesões geradas podem ser mutagênicas e contribuir para o processo de carcinogênese. Assim, desvios significativos da estrutura da dupla hélice desempenham um papel importante no metabolismo do DNA. Um biossensor voltamétrico baseado na imobilização de DNA de fita dupla (dsDNA) sobre eletrodos descartáveis foi desenvolvido para aplicação nos estudos de interação entre corantes têxteis e a molécula do DNA, na ausência e na presença de flavonóides em solução. Os eletrodos modificados foram colocados em contato com soluções de corantes têxteis da classe dos dispersos, o Disperso Orange 1 (DO1) e o Disperso Red 1 (DR1), e seus produtos de eletrólise por oxidação e por redução. A variação dos sinais de oxidação das bases guanina e adenina presentes no dsDNA imobilizado, obtidos antes e após cada interação, foi utilizada como parâmetro de análise dos resultados. O tempo para que a interação DNA:corante ocorresse foi avaliado utilizando o biossensor e estabeleceu-se 180 s. A concentração dos corantes foi analisada na faixa de 1,0 x 10-8 a 1,0 x 10-4 mol L-1, sendo que a variação do sinal voltamétrico das bases foi mais intensa para DR1 (sinais da guanina e adenina decresceram 48% e 51% do seu valor original, respectivamente), enquanto que na presença de DO1, as intensidades de corrente da guanina e adenina diminuíram 30% e 10% de seu valor original, respectivamente, quando comparada a mesma concentração dos corantes de 1,0 x 10-6 mol L-1. Além da diminuição da intensidade de corrente das bases guanina e adenina, o aparecimento de novos picos e deslocamentos do potencial de pico das bases foram observados após as interações com produtos de eletrólises. Estudos de interação também...
DNA molecule may be modified by electrophilic substances, either from endogenous or exogenous origin. Lesions generated may be mutagenic and contribute to the process of carcinogenesis. In this way, significant deviations on the double helix structure play an important role in the DNA metabolism. A biosensor based on double-stranded DNA (dsDNA) immobilization on disposable electrodes has been developed for application in interaction studies between textile dyes and DNA molecule in the absence and presence of flavonoids in solution. The modified electrodes were placed in solutions of disperse textile dyes, Disperse Orange 1 (DO1) and Disperse Red 1 (DR1), and their products of electrolyses by oxidation and reduction. The variation of the oxidation signals of guanine and adenine bases of the immobilized dsDNA, obtained before and after each interaction, was used as a parameter for analyzing the results. The time for DNA:dye interaction was evaluated using the biosensor and 180 s was established. The concentration of dyes was analyzed in the range from 1.0 x 10-8 to 1.0 x 10-4 mol L-1, and the bases voltammetric signal variation was more intense for DR1 (signals of guanine and adenine decreased 48% and 51% of its original value, respectively), whereas in the presence of DO1, the current intensities of guanine and adenine decreased by 30% and 10% of its original value, respectively, when compared the same dyes concentration of 1.0 x 10-6 mol L-1. Besides adenine and guanine current intensities decrease, the appearance of new peaks and peaks potential shifts were also observed after interactions with electrolysis products. Interaction studies were also performed by means of UV-Vis spectrophotometry in aqueous phase showed different effects of hypochromism and hiperchromism of DNA band after interactions... (Complete abstract click electronic access below)

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14

Pacífico, Mariana. "Estudo químico e atividades mutagênica e antiulcerogênica de Syngonanthus nitens (Bong.) Ruhland /." Araraquara : [s.n.], 2010. http://hdl.handle.net/11449/97968.

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Orientador: Lourdes Campaner dos Santos
Banca: 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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15

Severi, Juliana Aparecida. "Uso sustentável da biodiversidade brasileira prospecção químico-farmacológica de plantas superiores : Guapira noxia (Nyctaginaceae) /." Araraquara : [s.n.], 2007. http://hdl.handle.net/11449/97016.

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Orientador: Wagner Vilegas
Banca: Wagner Vilegas
Banca: Jairo Kenupp Bastos
Banca: Luiz Claudio Di Stasi
Resumo: Esse trabalho é parte do projeto temático BIOTA-FAPESP: "Uso Sustentável da Biodiversidade Brasileira: Prospecção Químico-Farmacológica de Plantas Superiores" e visa contribuir com a caracterização do Bioma-Cerrado do estado de São Paulo, investigando espécies brasileiras de interesse químico-medicinal. Dentre as espécies com particular interesse estão as do gênero Guapira (Nyctaginaceae), com informações etnofarmacológicas de uso para problemas estomacais. G. noxia é conhecida popularmente como "Maria-mole" ou "Capa-rosa" e tem ocorrência no cerrado brasileiro. Essa espécie é utilizada na medicina popular como antiúlcera. Apesar do uso popular, ainda não há informações sobre a composição química e ensaios farmacológicos desta espécie e que cuja caracterização está sendo descrita pela primeira vez. O extrato metanólico das folhas de G. noxia foi fracionado por técnicas cromatográficas convencionais (Permeação em gel, HPLC) e a as substâncias resultantes foram identificadas através de métodos espectroscópicos (RMN, IV, UV e EM). Esse trabalho levou à identificação de oito heterosídeos de flanovóides (com três e duas unidades de açúcares) derivados da quercetina, da isorhamnetina e do kaempferol, além da alantoína e de um ciclitol. Além disso, foi estabelecido o perfil cromatográfico do extrato metanólico, juntamente com a quantificação do teor de compostos fenólicos e de flavonóides totais, com vistas à sua completa caracterização química. O estudo farmacológico do extrato metanólico evidenciou principalmente as atividades antiúlcera, antimicrobiana e imunomodulatória. A presença dos flavonóides e demais compostos fenólicos pode justificar os efeitos biológicos atribuídos à espécie. Como conclusão, este estudo contribuiu para aprofundar o conhecimento químicofarmacológico sobre Guapira noxia, que ocorre no cerrado brasileiro.
Abstract: This work is part of the BIOTA-FAPESP project "Sustaintable use of the Brazilian Biodiversity: Chemical and Pharmacological Prospection on Higher Plants", which intents to contribute to improve the knowledge of the biome Cerrado of the State São Paulo, Brazil. Species from the Guapira (Nyctaginaceae) genus have special interest, since they are used in folk medicine as antiulcerogenic agent. G. noxia is known in folk medicine as "Maria-mole" or "Capa-rosa" and occurs naturally in the Brazilian cerrado, being used due to its antiulcerogenic propertie. Although the folk use, there is no data about chemical and pharmacological studies on this species. We describe here the first chemical and pharmacological characterization. The methanolic extract of G. noxia leaves was fractionated by chromatography techniques (GPC, HPLC) and the substances were identified by spectrometric methods (NMR, MS, IR, UV). This approach led to identification of eight heterosides (two and three glycosides) of flavonoids derived from quercetin, isorhamnetin and kaempferol, besides one allantoin and one cyclitol. Moreover, we have established the HPLC/UV/DAD chromatographic profile of this extract, as well as the spectrophotometric quantification of phenolic compounds and flavonoids. Pharmacological investigations showed antiulcerogenic, antimicrobial and immunomodulatory properties of the methanolic extract. The presence of flavonoids and phenolic compounds may probably explain the pharmacologicals effects of the polar extract of G. noxia and their use in folk medicine. In conclusion, this study contributed to improve the knowledge of the chemistry and pharmacological activities of Guapira noxia, an species that occurs in the Brazilian cerrado.
Mestre

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16

Uliana, Carolina Venturini. "Estudos da lesão ao DNA por corantes têxteis e da capacidade protetora de flavonóides empregando biossensor eletroquímico / Carolina Venturini Uliana. -." Araraquara, 2013. http://hdl.handle.net/11449/105701.

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Orientador: Hideko Yamanaka
Banca: Maria Valnice Boldrin
Banca: Silvia Helena Pires Serrano
Banca: Ronaldo Censi Faria
Banca: Paulo Roberto Brasil de Oliveira Marques
Resumo: A molécula do DNA pode ser modificada por substâncias eletrofílicas, tanto de origem exógena quanto endógena. As lesões geradas podem ser mutagênicas e contribuir para o processo de carcinogênese. Assim, desvios significativos da estrutura da dupla hélice desempenham um papel importante no metabolismo do DNA. Um biossensor voltamétrico baseado na imobilização de DNA de fita dupla (dsDNA) sobre eletrodos descartáveis foi desenvolvido para aplicação nos estudos de interação entre corantes têxteis e a molécula do DNA, na ausência e na presença de flavonóides em solução. Os eletrodos modificados foram colocados em contato com soluções de corantes têxteis da classe dos dispersos, o Disperso Orange 1 (DO1) e o Disperso Red 1 (DR1), e seus produtos de eletrólise por oxidação e por redução. A variação dos sinais de oxidação das bases guanina e adenina presentes no dsDNA imobilizado, obtidos antes e após cada interação, foi utilizada como parâmetro de análise dos resultados. O tempo para que a interação DNA:corante ocorresse foi avaliado utilizando o biossensor e estabeleceu-se 180 s. A concentração dos corantes foi analisada na faixa de 1,0 x 10-8 a 1,0 x 10-4 mol L-1, sendo que a variação do sinal voltamétrico das bases foi mais intensa para DR1 (sinais da guanina e adenina decresceram 48% e 51% do seu valor original, respectivamente), enquanto que na presença de DO1, as intensidades de corrente da guanina e adenina diminuíram 30% e 10% de seu valor original, respectivamente, quando comparada a mesma concentração dos corantes de 1,0 x 10-6 mol L-1. Além da diminuição da intensidade de corrente das bases guanina e adenina, o aparecimento de novos picos e deslocamentos do potencial de pico das bases foram observados após as interações com produtos de eletrólises. Estudos de interação também... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: DNA molecule may be modified by electrophilic substances, either from endogenous or exogenous origin. Lesions generated may be mutagenic and contribute to the process of carcinogenesis. In this way, significant deviations on the double helix structure play an important role in the DNA metabolism. A biosensor based on double-stranded DNA (dsDNA) immobilization on disposable electrodes has been developed for application in interaction studies between textile dyes and DNA molecule in the absence and presence of flavonoids in solution. The modified electrodes were placed in solutions of disperse textile dyes, Disperse Orange 1 (DO1) and Disperse Red 1 (DR1), and their products of electrolyses by oxidation and reduction. The variation of the oxidation signals of guanine and adenine bases of the immobilized dsDNA, obtained before and after each interaction, was used as a parameter for analyzing the results. The time for DNA:dye interaction was evaluated using the biosensor and 180 s was established. The concentration of dyes was analyzed in the range from 1.0 x 10-8 to 1.0 x 10-4 mol L-1, and the bases voltammetric signal variation was more intense for DR1 (signals of guanine and adenine decreased 48% and 51% of its original value, respectively), whereas in the presence of DO1, the current intensities of guanine and adenine decreased by 30% and 10% of its original value, respectively, when compared the same dyes concentration of 1.0 x 10-6 mol L-1. Besides adenine and guanine current intensities decrease, the appearance of new peaks and peaks potential shifts were also observed after interactions with electrolysis products. Interaction studies were also performed by means of UV-Vis spectrophotometry in aqueous phase showed different effects of hypochromism and hiperchromism of DNA band after interactions... (Complete abstract click electronic access below)
Doutor

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17

O'Reilly, James Daniel. "Antioxidant activity of dietary flavonoids." Thesis, King's College London (University of London), 1999. https://kclpure.kcl.ac.uk/portal/en/theses/antioxidant-activity-of-dietary-flavonoids(10c771a4-169d-405b-a1cd-354e86ebd109).html.

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18

Jaganath, Indu Bala. "Dietary flavonoids : bioavailability and biosynthesis." Thesis, University of Glasgow, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418903.

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Kyle, Janet A. M. "Flavonoids in health and disease." Thesis, University of Aberdeen, 2003. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU177273.

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The initial aim of this thesis was to gather, critically assess and collate all available compositional data for flavonoid compounds belonging to 5 out of 12 major flavonoid sub-classes - flavanones, flavones, flavonols, catechins and procyanidins - in edible food sources. A flavonoid food composition database for application in dietary assessment investigations was subsequently compiled. The completeness of the database was tested using a healthy North East of Scotland population. The ability of the Scottish Collaborative Group food frequency questionnaire (SCG FFQ) to estimate flavonoid intake was compared to 4-day weighed dietary records. This study demonstrated that the major source of dietary flavonols, catechins and procyanidins was black tea with added milk. However, the bio-availability of tea flavonoids was questionable, as flavonoids were known to readily bind to milk proteins in vitro. As a review of the literature was inconclusive with 2 studies supporting the hypothesis and 2 refuting it, a bio-availability study was subsequently completed. This investigation assessed the uptake of flavonoids and their effect on plasma antioxidant status after drinking black tea, black tea with milk and water and milk as a control. Findings suggested, that the possible exception of the flavonol, kaempferol, addition of milk to tea did not significantly negate increases in plasma flavonoid concentration or antioxidant activity. Finally, the hypothesis that low dietary flavonoid intake is associated with colon or rectal cancer risk was tested using the SCG FFQ applied to a population-based case-control study. Only the flavonol quercetin obtained from sources other that tea was strongly related to reduced risk of colon cancer in the North East of Scotland. However, further investigation is required to discern if this observed effect is due to quercetin per se or to other as yet unidentified components of fruit and vegetables which are co-associated with this flavonoid.

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Vega-Villa, Karina R. "Pharmacokinetic and pharmacodynamic investigations of selected chiral flavonoids." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Dissertations/Spring2009/k_vega-villa_042109.pdf.

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Caruso, Ícaro Putinhon. "Estudo da interação entre flavonóides e a albumina do soro humano /." São José do Rio Preto, 2012. http://hdl.handle.net/11449/87502.

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Orientador: Marinônio Lopes Cornélio
Banca: Hamilton Cabral
Banca: Marcelo Andrés Fossey
Resumo: Os flavonóides são uma grande classe de polifenóis ocorrendo de forma natural amplamente distribuídos nas plantas, essas moléculas exibem algumas atividades farmacológicas importantes como anti-inflamatória, antioxidante, anticancerígena e antibacteriana. A interação entre os flavonóides Rutina (Ru) e Guaijaverina (Gua) e a Albumina do Soro Humano (HSA) em pH 7,0 fisiológico foi investigado usando a técnica de espectroscopia de fluorescência de estado estacionário, cálculo ab initio e de modelagem molecular. A partir da supressão de fluorescência da HSA pelos flavonóides, a constante de supressão de Stern-Volmer ( SVK ) e sua forma modificada ( aK ) foram calculadas em 298, 303 e 308 K, como também os parâmetros termodinâmicos correspondentes H, G e S, para cada flavonóide. A análise do equilíbrio de ligação foi utilizada para determinar os valores do número de sítios de ligação ( n ) e a constante de ligação ( bK ) para a Rutina e a Guaijaverina em 298, 303 e 308 K. A distância média entre o doador (HSA-214Trp ) e o aceitador (Ru e Gua) foi estimada de acordo com a teoria de transferência de energia ressonante fluorescente. A otimização geométrica dos flavonóides Rutina e Guaijaverina foi realizada nos seus estados fundamentais usando o funcional DFT/B3LYP ab initio com um conjunto de bases 6-31G(d,p) utilizado nos cálculos. O cálculo de modelagem molecular indica que os flavonóides se localizam no sítio I da HSA, dentro do bolso hidrofóbico do subdomínio IIA. Os resultados teóricos obtidos pela modelagem molecular corroboram com os dados de espectroscopia de fluorescência
Abstract: Flavonoids are a large class of naturally occurring polyphenols widely distributed in plants, these molecules exhibit some important pharmacological activities like anti-inflammatory, antioxidant, anticancer, and antibacterial. The interaction between Rutina and Guaijaverin flavonoids and Human Serum Albumin (HSA) at physiological pH 7.0 was investigated by using the technique of fluorescence spectroscopy, ab initio and molecular modeling calculation. From the fluorescence quenching of the HSA by flavonoids, the Stern-Volmer quenching constant ( SVK ) and its modified form ( aK ) were calculated at 298, 303 and K308, as well as the corresponding thermodynamic parameters H, G and S, for each flavonoid. Analysis of binding equilibria was utilized to determine the number of binding sites ( n ) and binding constants ( bK ) values for Rutin and Guaijaverin at 298, 303 and K308 . The average distance between donor (HSA-214Trp ) e acceptor (Ru and Gua) was estimated according to the theory of fluorescence resonance energy transfer. The geometry optimization of Rutin and Guaijaverin flavonoids was performed in its ground state by using ab initio DFT/B3LYP functional with a 6-31G(d,p) basis set applied in calculations. Molecular modeling calculation indicated that the flavonoids are located in site I of HSA, within the hydrophobic pocket of the subdomain IIA. The theoretical results obtained by molecular modeling are corroborated by the fluorescence spectroscopy data
Mestre

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Rosenberg, Zand Rachel Stacey. "Flavonoids and steroid hormone-dependent cancers." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/NQ63739.pdf.

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23

Daubney, J. "The cardioprotective mechanisms of dietary flavonoids." Thesis, Nottingham Trent University, 2015. http://irep.ntu.ac.uk/id/eprint/27927/.

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Mitotic rat embryonic cardiomyoblast-derived H9c2 cells are widely used as a model cardiomyocyte to study the protective mechanisms of dietary flavonoids, but they lack features of fully differentiated cardiomyocytes. Therefore, this present study aimed to investigate the cytoprotective and cytotoxic effects of the dietary flavonoids quercetin, kaempferol, myricetin and two major quercetin metabolites, quercetin-3-glucoronide and 3’-O-methylquercetin, on fully differentiated H9c2 cells for the first time. The cardiomyocyte-like phenotype of the differentiated H9c2 cells was confirmed by monitoring the expression of cardiac specific troponin T, as well as through the identification of other cardiac specific cytoskeletal markers using MALDI-TOF MS/MS. The cytoprotective effect of quercetin, kaempferol, myricetin, quercetin-3-glucoronide and 3’-O-methylquercetin against hypoxia and H2O2-induced cell death was assessed by monitoring MTT reduction and LDH release. Furthermore the effect of quercetin pre-treatment on ERK1/2, PKB, JNK and p38 MAPK phosphorylation was monitored using western blotting. It was shown that quercetin was the most potent flavonoid at inducing a protective effect, and 3’-O-methylquercetin the most potent metabolite. Using western blotting it was shown that this protective effect is most likely due to quercetin-mediated inhibition of ERK1/2, PKB, JNK and p38 MAPK. Specific inhibitors of these protein kinases did not modulate the observed cytoprotective effect, or cause significant protection alone. The cytotoxic effects of dietary flavonoids, particularly quercetin, was monitored with MTT reduction, LDH release, western blotting to monitor phosphorylation of ERK1/2, PKB, JNK and p38 MAPK and activation of caspase-3, and monitoring intracellular ROS generation with DCFDA assay. The cytotoxic effect of quercetin was shown to be linked to intracellular ROS generation, caspase-3 activation and phosphorylation of ERK1/2, PKB, JNK and p38 MAPK. MALDI-TOF MS for the first time identified several proteins associated with the flavonoid-mediated cytoprotective effect and flavonoid pre-treatment in differentiated H9c2 cells. Most were shown to be linked to the regulation of MAPK and PI3K cell signalling pathways. This present study for the first time demonstrates the cytoprotective and cytotoxic effects of flavonoids on differentiated H9c2 cells, and has identified novel proteins associated with the cytoprotective effect.

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Chalumeau, Céline. "Développement d’outils chimiques pour l’élucidation de la biosynthèse des flavonoïdes du raisin : anthocyanes versus proanthocyanidines." Thesis, Bordeaux 1, 2010. http://www.theses.fr/2010BOR14188/document.

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Ces dernières années, des progrès remarquables ont été accomplis afin d’élucider la biosynthèse des flavonoïdes. Cependant les dernières étapes menant à la formation des proanthocyanidines ou tannins condensés issus de la vigne, restent à ce jour inconnues. Dans le but de déterminer si une ou plusieurs enzyme(s) spécifique(s) sont impliquées dans cette voie de biosynthèse, nous avons développé une approche de protéomique chimique, impliquant des matrices d’affinité constituées de substrats de type flavanols greffés sur un support solide. La validation de ces outils à l’aide de LDOX, une enzyme issue de Vitis vinifera a pu être menée à bien dans le cadre de ces travaux de thèse
Remarkable progress toward the complete elucidation of the biosynthesis of flavonoids has been accomplished during the last decade, but the final step leading to proanthocyanidins still remain to be elucidated, in particular, the exact nature of starter and extension units as well as the enzymatic or non enzymatic condensation process. In order to answer whether some specific enzymes are involved in the biosynthesis of grapevine proanthocyanidins, we have developped a chemical proteomics approach, with an affinity chromatography-based tool in which a flavanol type substrate is loaded on an appropriate solid support. The validation of these tools with the LDOX enzyme from Vitis vinifera was developped and performed in this Ph.D work

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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.

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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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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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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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)

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Tala, Viviane Raissa Sipowo [UNESP]. "Investigação de plantas africanas: Viviane Raïssa Sipowo Tala.-." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/105825.

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Le présent travail a pour objectif d’apporter notre contribution à l’étude de quelques plantes africaines en investiguant leur potentiel chimio-médicinal. Parmi les espèces ayant un intérêt particulier, ont été étudiées dans le cadre de ce travail, deux plantes médicinales camerounaises choisies en raison de leurs vertus thérapeutiques: la première, Parkia biglobosa (Fabaceae), est utilisée en médecine populaire contre la diarrhée et les maux d'estomac tandis que la seconde, Rumex abyssinicus (Polygonaceae), est utilisée dans le traitement de la constipation et de la gale. Les extraits au mélange dichlorométhane/méthanol (1:1, v/v) des écorces et des racines de P. biglobosa ainsi que ceux à l’éthanol des racines et des feuilles de R. abyssinicus ont été, chacun, préparés par macération, partitionnés à de l’acétate d'éthyle et/ou chloroforme et de l'eau puis fractionnés moyenant des techniques chromatographiques usuelles (gel de perméation, MPLC, HPLC). Les substances isolées ont été identifiées à l’aide des méthodes spectrométriques et spectroscopiques (RMN, UV et MS). Dans cette étude, ont été isolés et caractérisés, d’une part, des racines de P. biglobosa: un triterpène, deux dérivés de l’acide gallique et six dérivés de l’(épi)catéchine. Les analyses effectuées utilisant la technique [HPLC]-ESI-IT-MSn montrent des profiles chimiques qualitativement similaires entre l'écorce et les racines de P. biglobosa, analyses qui a conduit à la détection des proanthocyanidines et de leurs dérivés galoïdiques et glucuronidiques, certaines d'entre elles sous plusieurs formes isomères. Au moyen de cette technique, les proanthocyanidines de m/z 785 et 937 ont été caractérisées pour la prémière fois. Des extraits des feuilles et des racines... (Résumé complet accès életronique cidessous)
Este trabalho visa contribuir com a caracterização de espécies vegetais presentes na África, investigando seu potencial químico-medicinal. Dentre as espécies com particular interesse, foram investigadas a espécie Parkia biglobosa (Fabaceae), usada na medicina popular contra diarréia e dores de estômago, e Rumex abyssinicus (Polygonaceae), usada para tratar a prisão de ventre e a sarna. As espécies foram coletadas em Camarões e os extratos diclorometano/metanol (1:1, v/v) das cascas e raízes de P. biglobosa e etanólico das folhas e raízes de R. abyssinicus foram preparados por maceração, particionados com acetato de etila e/ou clorofórmio e água. Em seguida, foram fracionados usando técnicas cromatograficas convencionais (permeação em gel, MPLC, HPLC). As substâncias isoladas foram identificadas através de métodos espectroscόpicos e espectrométricos (RMN, UV e EM). Com este estudo, foram identificados nas raízes de P. biglobosa um triterpeno, dois derivados do ácido gálico e seis derivados da (epi)catequina. As análises por [HPLC]-ESI-IT-MSn apontaram perfis químicos qualitativamente semelhantes entre as cascas e as raízes de P. biglobosa, o que levou à detecção de proantocianidinas, bem como de seus derivados galoilados e glucuronilados, algumas delas em diferentes formas isoméricas. Com este método, as proantocianidinas em m/z 785 e 937 foram caracterizadas pela primeira vez. Este estudo também possibilitou o isolamento de quatro antraquinonas, dois flavonόides e dos ácidos trans e cis-para-cumárico das raízes e folhas de R. abyssinicus. Em relação as atividades biolόgicas investigadas, verificou-se que o extrato diclorometano/metanol das cascas e raízes de P. biglobosa e/ou as frações semipurificadas e os extratos etanólico das folhas e raízes de R. abyssinicus apresentaram...

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Vieira, Silvia Cristina Heredia [UNESP]. "Extratos padronizados para o tratamento de doenças crônicas: Serjania marginata Casar. (Sapindaceae)." Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/114026.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
A família Sapindaceae é bastante estudada do ponto de vista farmacológico. A Serjania marginata Casar., uma espécie dessa família, é indicada, popularmente, para dores de estômago. Os objetivos deste trabalho foram estabelecer o perfil químico, isolar e caracterizar os constituintes químicos do extrato EtOH 70% de S. marginata, quantificar as substâncias marcadoras da espécie, avaliar a toxicidade aguda, neurotoxicidade, atividade anti-ulcerogênica, antiradicalar e mutagênica do extrato, determinar o teor de fenóis e flavonoides totais e avaliar a espécie no cultivo ex situ. Os estudos foram realizados com as folhas de plantas nativas do Cerrado e cultivadas no Horto de Plantas Medicinais, da UFGD, em Dourados-MS. O maior rendimento foi da espécie nativa coletada em fevereiro de 2011 (32,6%). Pela triagem fitoquímica, determinou-se que o extrato é composto por flavonoides, saponinas, taninos, compostos fenólicos e esteróides. Foram isoladas quinze substâncias, das classes dos flavonoides, taninos e saponinas, sendo o ácido oleanólico 3-O-α-L-arabinopiranosil(1→3)-α-L-ramnopiranosil(1→2)[β-D-glicopiranosil(1→4)]-α-L-arabinopiranosídeo e a 7,5”-anidroapigenina 8-C-α-(2,6-dideoxi-5-hidroxi-ribo-hexopiranosil)-4'-O-β-D-glucopiranosídeo, descritos pela primeira vez na literatura. O extrato não apresentou efeitos tóxicos nem neurotóxicos no uso oral agudo e não foi mutagênico. Evidenciou-se também significativa atividade anti-úlcera para o extrato em diversos modelos farmacológicos, avaliados in vivo. Os extratos das folhas colhidas em diferentes épocas de cultivo, avaliados através do uso do reagente DPPH, apresentaram alta atividade antiradicalar, quando comparados ao ácido gálico e quercetina, especialmente devido à presença de taninos. As plantas coletadas após o florescimento apresentaram maior quantidade de compostos fenólicos e, antes do florescimento, maior concentração de flavonoides...
Sapindaceae family is extensively studied on a pharmacological point of view. Serjania marginata Casar., a specie of this family, is indicated popularly for stomach aches. The objectives of this work were to standardize the chemical profile, to characterize the chemical composition of 70% EtOH extract from S. marginata, to quantify the marker substances for the specie, to assess the acute toxicity, neurotoxicity, anti-ulcerogenic, antiradical and mutagenic activities of the extract, to determine the total phenolic and flavonoid contents and to evaluate conditions of ex situ cultivation for the specie. The studies were performed with leaves of native plants from the Cerrado and of plants grown in the Garden of Medicinal Plants from the UFGD, Dourados-MS. The highest contents were achieved by the native accesses collected during February 2011 (32.6%). During the chemical screening, it was determined that the extract was composed by flavonoids, saponins, tannins, phenols and steroids. Fifteen substances were isolated which were classified as flavonoids, tannins and saponins, and the oleanolic acid 3-O-α-L-arabinopyranosyl(1→3)-α-L-rhamnopyranosyl(1→2)[β-D-glucopyranosyl(1→4)]-α-L-arabinopyranoside and 7,5”-anhidroapigenin 8-C-α-(2,6-dideoxy-5-hydroxy-ribo-hexopyranosyl)-4'-O-β-D-glucopyranoside described for the first time in the literature. The extract here studied did not show any toxic or neurotoxic effect by acute oral dose neither presented any mutagenic potential. Significant anti-ulcer activity of the extract was evidenced when applied in different pharmacological modulations, evaluated in vivo. The extracts from leaves harvested in different growing seasons evaluated through the use of the reagent DPPH showed high antiradical activity when compared to the gallic acid and quercetin, mainly due to the presence of tannins. Plants collected after flowering showed higher amounts of phenolic compounds and, before flowering, ...
FAPESP: 11/08880-4

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Tala, Viviane Raissa Sipowo. "Investigação de plantas africanas / Viviane Raïssa Sipowo Tala.-." Araraquara, 2013. http://hdl.handle.net/11449/105825.

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Orientador: Wagner Vilegas
Coorientador: Nkengfack Augustin Ephrem
Banca: Ana Helena Januário
Banca: Adriana Zerlotti Mercadante
Banca: Marcos José Salvador
Resumo: Este trabalho visa contribuir com a caracterização de espécies vegetais presentes na África, investigando seu potencial químico-medicinal. Dentre as espécies com particular interesse, foram investigadas a espécie Parkia biglobosa (Fabaceae), usada na medicina popular contra diarréia e dores de estômago, e Rumex abyssinicus (Polygonaceae), usada para tratar a prisão de ventre e a sarna. As espécies foram coletadas em Camarões e os extratos diclorometano/metanol (1:1, v/v) das cascas e raízes de P. biglobosa e etanólico das folhas e raízes de R. abyssinicus foram preparados por maceração, particionados com acetato de etila e/ou clorofórmio e água. Em seguida, foram fracionados usando técnicas cromatograficas convencionais (permeação em gel, MPLC, HPLC). As substâncias isoladas foram identificadas através de métodos espectroscόpicos e espectrométricos (RMN, UV e EM). Com este estudo, foram identificados nas raízes de P. biglobosa um triterpeno, dois derivados do ácido gálico e seis derivados da (epi)catequina. As análises por [HPLC]-ESI-IT-MSn apontaram perfis químicos qualitativamente semelhantes entre as cascas e as raízes de P. biglobosa, o que levou à detecção de proantocianidinas, bem como de seus derivados galoilados e glucuronilados, algumas delas em diferentes formas isoméricas. Com este método, as proantocianidinas em m/z 785 e 937 foram caracterizadas pela primeira vez. Este estudo também possibilitou o isolamento de quatro antraquinonas, dois flavonόides e dos ácidos trans e cis-para-cumárico das raízes e folhas de R. abyssinicus. Em relação as atividades biolόgicas investigadas, verificou-se que o extrato diclorometano/metanol das cascas e raízes de P. biglobosa e/ou as frações semipurificadas e os extratos etanólico das folhas e raízes de R. abyssinicus apresentaram... (Resumo completo, clicar acesso eletrônico abaixo)
Résumé: Le présent travail a pour objectif d'apporter notre contribution à l'étude de quelques plantes africaines en investiguant leur potentiel chimio-médicinal. Parmi les espèces ayant un intérêt particulier, ont été étudiées dans le cadre de ce travail, deux plantes médicinales camerounaises choisies en raison de leurs vertus thérapeutiques: la première, Parkia biglobosa (Fabaceae), est utilisée en médecine populaire contre la diarrhée et les maux d'estomac tandis que la seconde, Rumex abyssinicus (Polygonaceae), est utilisée dans le traitement de la constipation et de la gale. Les extraits au mélange dichlorométhane/méthanol (1:1, v/v) des écorces et des racines de P. biglobosa ainsi que ceux à l'éthanol des racines et des feuilles de R. abyssinicus ont été, chacun, préparés par macération, partitionnés à de l'acétate d'éthyle et/ou chloroforme et de l'eau puis fractionnés moyenant des techniques chromatographiques usuelles (gel de perméation, MPLC, HPLC). Les substances isolées ont été identifiées à l'aide des méthodes spectrométriques et spectroscopiques (RMN, UV et MS). Dans cette étude, ont été isolés et caractérisés, d'une part, des racines de P. biglobosa: un triterpène, deux dérivés de l'acide gallique et six dérivés de l'(épi)catéchine. Les analyses effectuées utilisant la technique [HPLC]-ESI-IT-MSn montrent des profiles chimiques qualitativement similaires entre l'écorce et les racines de P. biglobosa, analyses qui a conduit à la détection des proanthocyanidines et de leurs dérivés galoïdiques et glucuronidiques, certaines d'entre elles sous plusieurs formes isomères. Au moyen de cette technique, les proanthocyanidines de m/z 785 et 937 ont été caractérisées pour la prémière fois. Des extraits des feuilles et des racines... (Résumé complet accès életronique cidessous)
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Vieira, Silvia Cristina Heredia. "Extratos padronizados para o tratamento de doenças crônicas : Serjania marginata Casar. (Sapindaceae) /." Araraquara, 2014. http://hdl.handle.net/11449/114026.

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Orientador : Wagner Vilegas
Banca: Ana María Simonet Morales
Banca: Cássia Regina Primila Cardoso
Banca: Luís Vitor Silva do Sacramento
Banca: Marcos Hikari Toyama
Resumo: A família Sapindaceae é bastante estudada do ponto de vista farmacológico. A Serjania marginata Casar., uma espécie dessa família, é indicada, popularmente, para dores de estômago. Os objetivos deste trabalho foram estabelecer o perfil químico, isolar e caracterizar os constituintes químicos do extrato EtOH 70% de S. marginata, quantificar as substâncias marcadoras da espécie, avaliar a toxicidade aguda, neurotoxicidade, atividade anti-ulcerogênica, antiradicalar e mutagênica do extrato, determinar o teor de fenóis e flavonoides totais e avaliar a espécie no cultivo ex situ. Os estudos foram realizados com as folhas de plantas nativas do Cerrado e cultivadas no Horto de Plantas Medicinais, da UFGD, em Dourados-MS. O maior rendimento foi da espécie nativa coletada em fevereiro de 2011 (32,6%). Pela triagem fitoquímica, determinou-se que o extrato é composto por flavonoides, saponinas, taninos, compostos fenólicos e esteróides. Foram isoladas quinze substâncias, das classes dos flavonoides, taninos e saponinas, sendo o ácido oleanólico 3-O-α-L-arabinopiranosil(1→3)-α-L-ramnopiranosil(1→2)[β-D-glicopiranosil(1→4)]-α-L-arabinopiranosídeo e a 7,5"-anidroapigenina 8-C-α-(2,6-dideoxi-5-hidroxi-ribo-hexopiranosil)-4'-O-β-D-glucopiranosídeo, descritos pela primeira vez na literatura. O extrato não apresentou efeitos tóxicos nem neurotóxicos no uso oral agudo e não foi mutagênico. Evidenciou-se também significativa atividade anti-úlcera para o extrato em diversos modelos farmacológicos, avaliados in vivo. Os extratos das folhas colhidas em diferentes épocas de cultivo, avaliados através do uso do reagente DPPH, apresentaram alta atividade antiradicalar, quando comparados ao ácido gálico e quercetina, especialmente devido à presença de taninos. As plantas coletadas após o florescimento apresentaram maior quantidade de compostos fenólicos e, antes do florescimento, maior concentração de flavonoides...
Abstract: Sapindaceae family is extensively studied on a pharmacological point of view. Serjania marginata Casar., a specie of this family, is indicated popularly for stomach aches. The objectives of this work were to standardize the chemical profile, to characterize the chemical composition of 70% EtOH extract from S. marginata, to quantify the marker substances for the specie, to assess the acute toxicity, neurotoxicity, anti-ulcerogenic, antiradical and mutagenic activities of the extract, to determine the total phenolic and flavonoid contents and to evaluate conditions of ex situ cultivation for the specie. The studies were performed with leaves of native plants from the Cerrado and of plants grown in the Garden of Medicinal Plants from the UFGD, Dourados-MS. The highest contents were achieved by the native accesses collected during February 2011 (32.6%). During the chemical screening, it was determined that the extract was composed by flavonoids, saponins, tannins, phenols and steroids. Fifteen substances were isolated which were classified as flavonoids, tannins and saponins, and the oleanolic acid 3-O-α-L-arabinopyranosyl(1→3)-α-L-rhamnopyranosyl(1→2)[β-D-glucopyranosyl(1→4)]-α-L-arabinopyranoside and 7,5"-anhidroapigenin 8-C-α-(2,6-dideoxy-5-hydroxy-ribo-hexopyranosyl)-4'-O-β-D-glucopyranoside described for the first time in the literature. The extract here studied did not show any toxic or neurotoxic effect by acute oral dose neither presented any mutagenic potential. Significant anti-ulcer activity of the extract was evidenced when applied in different pharmacological modulations, evaluated in vivo. The extracts from leaves harvested in different growing seasons evaluated through the use of the reagent DPPH showed high antiradical activity when compared to the gallic acid and quercetin, mainly due to the presence of tannins. Plants collected after flowering showed higher amounts of phenolic compounds and, before flowering, ...
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Tangerina, Marcelo Marucci Pereira. "Extratos padronizados para o tratamento de doenças crônicas : Machaerium hirtium /." Araraquara : [s.n.], 2012. http://hdl.handle.net/11449/97015.

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Orientador: Wagner Vilegas
Coorientador: 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
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Marques, Isabella Barbosa. "Época de plantio e tempo de incorporação de torta de mamona no cultivo orgânico de Calendula officinalis L. /." Botucatu, 2019. http://hdl.handle.net/11449/181702.

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Orientador: Filipe Pereira Giardini Bonfim
Banca: Nathalia de Souza Parreiras
Banca: Jordany de Oliveira Gomes
Resumo: O manejo cultural de plantas medicinais é fator que influencia fortemente na síntese de metabólitos secundários, sendo a adubação fundamental para alcançar boa produtividade e teores satisfatórios de compostos bioativos. Dessa forma, o objetivo do estudo foi avaliar a produção de capítulos florais, compostos fenólicos totais, flavonoides totais, bem como o crescimento de calêndula (Calendula officinalis L.) submetida a tempos de incorporação de torta de mamona em diferentes épocas de cultivo. O trabalho foi divido em dois capítulos, no primeiro avaliou-se a massa fresca e seca dos capítulos florais, número de capítulos florais, teor de compostos fenólicos e de flavonoides de capítulos florais em três tempos de incorporação de torta mamona (28 e 14 dias antes do transplantio e no dia do transplantio) associados a quatro épocas de cultivo. A análise dos dados revelou que a produção de material vegetal foi influenciada tanto pelo tempo de incorporação da torta de mamona quanto pela época de cultivo, apresentando interação entre os fatores. Na época de cultivo 1 médias inferiores foram verificadas com a incorporação 0 DAT. Menores médias foram encontradas também com incorporação 28 DAT na época de cultivo 3. Nas épocas de cultivo 2 e 4 não houve diferença estatística entre os tempos de incorporação, entretanto a época de cultivo 2 apresentou valores inferiores de produção de material vegetal quando comparada às demais épocas. Deste modo, não é indicado o cultivo em condições clim... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The cultural management of medicinal plants is a factor that strongly influences the synthesis of secondary metabolites, with the fertilization being fundamental to achieve good productivity and satisfactory levels of bioactive compounds. Thus, the objective of the study was to evaluate the production of floral chapters, total phenolic compounds, total flavonoids, as well as the growth of calendula (Calendula officinalis L.) submitted to times of incorporation of castor bean cake at different growing seasons. The work was divided in two chapters, in the first one was evaluated the fresh and dry mass of the floral chapters, number of floral chapters, content of phenolic compounds and flavonoids of floral chapters in three times of incorporation of castor bean cake (28 and 14 days before transplanting and on the day of transplanting) associated with four growing seasons. The data analysis has revealed that the production of plant material was influenced both by the incorporation timeof the castor bean cake and the growing season, showing interaction between the factors. At the time of cultivation 1 lower means were verified with the 0 DAT incorporation. Minor means were also found with 28 DAT incorporation at the time of cultivation 3. In the growing seasons 2 and 4 there was no statistical difference between the incorporation times, however the crop season 2 presented lower values of plant material compared to the other. Thus, cultivation is not indicated in climatic conditions similar to those of the growing season 2 (high rainfall and high temperatures) due to the low productivity of inflorescences. The amount of phenolic compounds did not present significant differences depending on the treatments. Lower mean values in the flavonoid amount were observed with the incorporation of 28 days before the transplanting in the growing season 4. In Chapter 2, the influence of three incorporation ...
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33

Nunes, Kelly de Nazaré Maia 1981. "Processamento térmico e estádio fenológico na atividade antioxidante do jambu /." Botucatu, 2016. http://hdl.handle.net/11449/138319.

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Orientador: Giuseppina Pace Pereira Lima
Banca: Igor Otavio Minatel
Banca: Camila Renata Correa Camacho
Banca: Willian Hiroshi Suekane Takata
Banca: Maíra Rodrigues Uliana
Resumo: O jambu (Spilanthes oleracea L.) é uma hortaliça não convencional utilizada na preparação de vários pratos típico na região norte do Brasil, no qual pode ser consumida crua ou cozida, apresentando importantes propriedades nutricionais e antioxidantes. O presente estudo tem por objetivo investigar os efeitos dos diferentes métodos e tempo de cocções na atividade antioxidante do jambu. Foi realizada a análise de variância em parcelas subdividida, no esquema fatorial de 3 métodos de cocção (fervura, micro-onda e vapor) e 3 tempos de cozimento (5, 10 e 15 min) mais o in natura, com 4 repetições, em triplicata. Os resultados foram apresentados como média aritmética ± DP (desvio padrão). E a comparação entre os tratamentos foi realizada pelo teste Scott-Knott a 5 % de probabilidade. Neste estudo, observou-se que o jambu apresentou grande potencial antioxidante nas duas fase de desenvolvimento. E quanto ao processamento térmico, observou-se que a temperatura promoveu aumento ou estabilidade dos compostos antioxidantes presente na planta, promovendo efeito maior sobre os compostos fenólicos, carotenoides, clorofila total e nas atividades antioxidantes pelos métodos DPPH e FRAP para as duas fases de desenvolvimento do jambu. A vitamina C diminuiu após processamento térmico. Os flavonoides em plantas na fase vegetativa diminuíram, após cozimento, assim como a atividade antioxidante determinada pelo método FRAP em plantas na fase de floração. Diante do exposto, conclui-se que o jambu ap... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The Jambu (Spilanthes oleracea L.) is an unconventional vegetables used to prepare several typical dishes in northern Brazil, which can be eaten raw or cooked, with important nutritional and antioxidant properties. This study aimed to investigate the effects of different methods and cooking cycles were evaluated time in antioxidant activity of jambu. Analysis of variance in subdivided plots was carried out in factorial 3 cooking methods (boiling, micro-wave and steam) and 3 cooking times (5, 10 and 15 min) plus fresh, with four replications in triplicate. The results were presented as arithmetic mean ± SD (standard deviation). And the comparison between treatments was performed by test Scott-Knott at 5% probability. As for the thermal processing, it was observed that the temperature promoted the increase or stabilization of the antioxidant compounds present in the plant, promoting greater effect on phenolic compouds, carotenoids, chlorophyll and the antioxidant activity by DPPH methods for the two phases of development jambu. Vitamin C decreased after thermal processing. The flavonoids in plants in the vegetative stage decreased after cooking, the antioxidant activity as determined by the FRAP method at flowering plants. On the above, it is concluded that the jambu has great antioxidant potential, in both development phases, even after being subjected to thermal processing. The lower losses of antioxidant compounds ran with the use of steam and microwaves, boiled for 5 minute... (Complete abstract click electronic access below)
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34

Hohnová, Barbora. "Studium přírodních látek obsažených ve vybraných bylinách a méně obvyklých druzích drobného ovoce." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2010. http://www.nusl.cz/ntk/nusl-233303.

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Flavonoids are natural compounds widely distributed in plant kingdom. They are inseparable from human diet because they showed a protective effect against cancer, stroke and coronary heart diseases related to their antioxidant properties. Therefore, rapid and efficient extraction procedure prior to chromatographic analysis is required. The liquid extraction at elevated temperature and pressure – Pressurized fluid extraction (PFE) and Pressurized hot water extraction (PHWE), present fast, effective and environmentally friendly extraction methods for the determination of flavonoids in plant materials. PFE and PHWE followed by reversed phase high-performance liquid chromatography with UV-visible detection have been utilized for the determination of a group of flavonoids (rutin, myricetin, quercetin, luteolin, apigenin and kaempferol) in the leaves and berries of less common plants. The matrices were extracted by methanol, ethanol and water at higher temperature 40-120 oC and pressure 15 MPa during 15 minutes. The obtained results were compared with conventional Soxhlet extraction and ultrasound-assisted extraction, the same solvents were used. The most effective extraction of selected flavonoids was achieved by PHWE. PFE showed the extraction yields comparable to those of the Soxhlet extraction, and the lowest extraction power was displayed by ultrasound-assisted extraction.

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Rendeiro, Ana Catarina. "The effects of flavonoids and flavonoid-rich blueberries on memory and the mechanisms by which these effects are mediated." Thesis, University of Reading, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.552993.

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It is widely accepted that diet strongly influences the incidence and onset of both cardiovascular diseases and neurodegeneration. Recently, phytochemical-rich foods, particularly those rich in flavonoids, such as blueberries, green tea and cocoa, have been shown to have a positive impact on memory and learning and cognitive function in both animals and humans. The mechanisms by which flavonoids exert these actions on cognitive performance are starting to emerge with evidence suggesting that they may modulate the activation status of neuronal receptors, signaling proteins and gene expression in the hippocampus. In the present Thesis we further explore the mechanisms by which flavonoids, present in blueberry, affect memory and learning in both young and aged rodents and relate such changes in the brain with behavioural cognitive outcomes. We show for the first time that pure flavonoids present in blueberry, particularly the flavanol monomers (- )-epicatechin and catechin and anthocyanins, are capable of mediating improvements in spatial memory in aged animals when dosed at the same levels they are found within the blueberry. This data suggests that flavonoids are the likely causal agents that mediate the cognitive effects of blueberry in vivo. We also show a positive impact of blueberry supplementation on spatial memory in young rodents in two separate experiments using well-establlshed behavioural paradigms. Mostly importantly we found that chronic blueberry intervention causes an up-regulation of hippocampal BDNF at protein level and at mRNA level in both young and aged animals, reinforcing the importance of this neurotrophin in the blueberry- induced learning and memory improvements. A more detailed analysis of the mechanisms underlying the impact of flavonoid-rich blueberries on memory revealed an increase in PSA-NCAM positive neurons in the dentate gyrus which is known to mediate synaptic transmission and neuronal remodeling. Further increases in NR2B-containing NMDR receptors in the hippocampus correlate with up-regulation with PSA-NCAM, suggesting an enhancement of synaptic plasticity, likely to be driven by an increase in glutamate signaling. As such, these changes seem to be mediated by central signaling pathways utilized in learning processes, notably ERK-CREB-BDNF and Akt-mTOR-ARC. Overall, our results provide further support for the impact of flavonoid-rich blueberries on learning performance in aged rodents as well as in young healthy rodents, suggesting a potential mechanism by which flavonoids act in the brain.

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Peter, Martin G., Abiy Yenesew, Hannington Twinomuhwezi, Jacques M. Kabaru, Hoseah M. Akala, Bernard T. Kiremire, Matthias Heydenreich, Fredrick Eyase, Norman C. Waters, and Douglas S. Walsh. "Antiplasmodial and larvicidal flavonoids from Derris trifoliata." Universität Potsdam, 2009. http://opus.kobv.de/ubp/texte_eingeschraenkt_verlag/2010/4461/.

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From the dichloromethane-methanol (1:1) extract of the seed pods of Derris trifoliata, a new flavanone derivative (S)-lupinifolin 4´-methyl ether was isolated. In addition, the known flavonoids lupinifolin and rotenone were identified. The structures were determined on the basis of spectroscopic evidence. Lupinfolin showed moderate in vitro antiplasmodial activity against the D6 (chloroquine-sensitive) and W2 (chloroquineresistant) strains of Plasmodium falciparum. The different parts of this plant showed larvicidal activities against Aedes aegypti and rotenoids were identified as the active principles.

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Resende, Flávia Aparecida [UNESP]. "Estudo do potencial antimutagênico, mutagênico, estrogênico e antibacteriano de flavonoides." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/104031.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Universidade Estadual Paulista (UNESP)
Os flavonoides exibem uma multiplicidade de atividades biológicas tanto in vivo como in vitro. No entanto, não existem dados suficientes para fornecer provas conclusivas sobre os efeitos benéficos da maioria das subclasses de flavonoides. Dessa maneira, neste estudo tornou-se relevante avaliar a mutagenicidade, antimutagenicidade, estrogenicidade e atividade antibacteriana dos flavonoides, com o objetivo de traçar o perfil relação estrutura-atividade, uma vez que a atividade biológica dos flavonoides depende da sua estrutura química. A mutagenicidade e antimutagenicidade foram avaliadas pelo teste de Ames, em cepas de Salmonella typhimurium TA98, TA100 e TA102, com e sem ativação metabólica. Para comparação do efeito protetor dos flavonoides foram utilizados 4-nitro-o-fenilenodiamina (NPD), azida sódica (AZS) e mitomicina C (MMC) como mutágenos de ação direta e benzo[a]pireno (B[a]P), aflatoxina B1 (AFB1) e 2-aminoantraceno (2-AA) como mutágenos de ação indireta. A atividade estrogênica foi avaliada por meio do ensaio com leveduras recombinantes (RYA - Recombinant Yeast Assay) e pelo ensaio de proliferação de células de câncer de mama humano (MCF-7⁄BUS) responsivas à estrógeno (E-screen). A determinação da atividade antibacteriana in vitro foi realizada neste estudo utilizando a técnica de diluição em microplacas, com as bactérias Staphylococcus aureus ATTC 25923 e Escherichia coli ATCC 25922. Os compostos avaliados foram: quercetina, kaempferol, luteolina, fisetina, crisina, galanina, flavona, 3-hidroxiflavona, 5- hidroxiflavona e 7-hidroxiflavona. No teste de Ames, a quercetina mostrou-se diretamente mutagênica na linhagem TA98 e antimutagênica...
The flavonoids exhibit a wide range of biological activities both in vivo and in vitro. However, there are insufficient data to provide conclusive evidence on the health effects of most flavonoid subclasses. Thus, is relevant to assess the mutagenicity, antimutagenicity, estrogenicity and antibacterial activity of flavonoids with the aim of tracing the structure-mutagenicity relationship profile, since the biological activity of flavonoids is governed by their chemical structure. The mutagenicity and antimutagenicity was assayed by the Ames test, with Salmonella typhimurium strains TA98, TA100 and TA102, carried out with and without metabolic activation. To compare the protective effect of flavonoids were used 4-nitro-o-phenylenediamine (NPD), sodium azide (AZS) and mitomycin C (MMC) as direct acting mutagens and benzo[a]pyrene (B[a]P), aflatoxin B1 (AFB1) e 2-aminoanthracene (2-AA) as indirect acting mutagens. The estrogenic activity was assayed by recombinant yeast assay (RYA) and by proliferation assay of cells of human breast cancer (MCF-7⁄ BUS) responsive to estrogen (E-screen). The determination of antibacterial activity in vitro was performed in this study by technique of dilution in microplates, with the bacteria Staphylococcus aureus ATTC 25923 and Escherichia coli ATCC 25922. The evaluated compounds were: quercetin, kaempferol, luteolin, fisetin, chrysin, galangin, flavones, 3-hydroxyflavone, 5- hydroxyflavone and 7- hydroxyflavone. In the Ames test, quercetin was directly mutagenic... (Complete abstract click electronic access below)

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Lemes, Geralda de Fátima. "Contribuição ao estudo químico de espécies da família Cucurbitaceae juss. e Rubiaceae juss. gêneros: Cayaponia Silva Manso e Psychotria L." Universidade Federal de Goiás, 2015. http://repositorio.bc.ufg.br/tede/handle/tede/4857.

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Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG
This work describes the chemical evaluation and, in parallel, the investigation of antioxidant and antimicrobial activity of four medicinal species of Brazilian Cerrado, Cayaponia espelina (Silva Manso) Cogn., C. citrullifolia (Griseb.) Cogn., C. weddellii (Naudin) Gomes-Klein (Cucurbitaceae) and Psychotria trichophora Müll. Arg. (Rubiaceae). The study of ethanol extracts of the species mentioned above led to the isolation of several classes of secondary metabolites, many of them presenting biological activity. Evaluation of ethyl acetate fractions of the leaves of C. espelina and n-butanol and hydromethanol fractions of C. citrullifolia led to the isolation and structural elucidation of seven compounds: luteolin (CE- 1), luteolin 4'-O-glucoside (CE-2), luteolin 7-O-glucoside (CE-3), kaempferol 3,7- O-α-L-dirhamnoside (CC-1), benzyl-O-β-D-xylopyranosyl-(1→6)-β-Dglucopyranoside (CC-4), salicylic acid 2-O-β-glucopyranoside (CC-3) and vicenin-2 (CC-2). The glucosides CE-2 and CE-3 found in C. espelina were also found in ethyl acetate fraction from C. weddellii leaves, indicating that there might be a chemical similarity between these species. The fourth species investigated in this study was P. trichophora and the chemical study of ethyl acetate fraction of its leaves led to the isolation and structural elucidation of six compounds: camelliaside B (PT-3), kaempferol-3-O-α-L-rhamnopyranosyl-(1→6)-[β-Dxylopyranosyl-( 1→2)]-β-D-galactopyranoside (PT-4), kaempferol-3-O-[β-Dxylopyranosyl-( 1→3)-α-L-rhamnopyranosyl-(1→6)]-β-D-galactopyranoside (PT- 5), kaempferol-3-O-robinoside (PT-2) and 3-O-p-coumaroylquinic acid (PT-6). Coumarin scopoletin (PT-1) were identified from its roots. Structural identification of compounds was performed by spectroscopic analysis including IR and 1H and 13C NMR, in one-and two-dimensions. Flavonoids PT-4 and PT-5, previously isolated in the Fabaceae and Leguminosae families, were described for the first time in Rubiaceae. Furthermore, CCDA analysis of acid-base fractions obtained from P. trichophora leaves did not result positive for alkaloids against the Dragendorff reagent. Preliminary tests in Escherichia coli showed that the ethyl acetate fraction from C. espelina presents pharmacological potential, inhibiting 74 % of bacterial growth at a 82 μg/mL concentration. This fraction also exhibited strong antioxidant activity, with IC50 value of 5.40 ± 0.16 μg/ml, being comparable to that of the commercial antioxidant, ascorbic acid. Extracts from C. espelina and C. weddelli were the most promising antioxidants with IC50 values of 131 ± 0.31 and 13.14 ± 0.57 μg/mL, respectively. In preliminary bioassays against Sarcoma 180 tumor cell line, all tested samples presented low activity despite the literature data for antitumor activity of the isolated flavonoids.
O presente trabalho descreve o estudo químico e, paralelamente, a investigação das atividades antioxidante e antimicrobiana de quatro espécies medicinais do Cerrado goiano, Cayaponia espelina (Silva Manso) Cogn., C. citrullifolia (Griseb.) Cogn., C. weddellii (Naudin) Gomes-Klein (Cucurbitaceae) e Psychotria trichophora Müll. Arg. (Rubiaceae). O estudo dos extratos etanólicos das espécies citadas conduziu ao isolamento de metabólitos secundários de diversas classes, sendo vários bioativos. O estudo da fração acetato de etila das folhas de C. espelina e das frações n-butanólica e hidrometanólica de C. citrullifolia viabilizou o isolamento e elucidação estrutural de sete compostos: luteolina (CE- 1), luteolina 4’-O-β-D-glicopiranosídeo (CE-2), luteolina 7-O-β-Dglicopiranosídeo (CE-3), canferol 3,7-di-O-α-L-ramnopiranosídeo (CC-1), benzil- O-β-D-xilopiranosil-(1→6)-β-D-glicopiranosídeo (CC-4), ácido β-Oglucosilsalicílico (CC-3) e vicenina-2 (CC-2). Com exceção da vicenina-2, todos os outros compostos estão sendo relatados pela primeira vez no gênero Cayaponia. O estudo da fração acetato de etila das folhas de C. weddellii levou aos mesmos glicosídeos (CE-2 e CE-3) relatados em C. espelina. A quarta espécie investigada neste trabalho foi P. trichophora. O estudo químico da fração acetato de etila das folhas propiciou o isolamento e elucidação estrutural de seis compostos: cameliasídeo B (PT-3), canferol-3-O-{β-D-xilopiranosil-(1→2)-[α-Lraminopiranosil-( 1→6)]}-β-D-galactopiranosídeo (PT-4), canferol-3-O-[β-Dxilopiranosil-( 1→3)-α-L-raminopiranosil-(1→6)]-β-D-galactopiranosídeo (PT-5), canferol-3-O-β-D-robinosídeo (PT-2) e ácido 5-p-coumaroilquínico (PT-6). Nas raízes foi identificada a cumarina escopoletina (PT-1). A elucidação estrutural dos compostos foi realizada através de análise espectroscópica, tais como IV e RMN de 1H e 13C, experimentos uni e bidimensionais.Os flavonoides PT-4 e PT- 5 estão sendo descritos pela primeira vez em Rubiaceae, isolados anteriormente apenas nas famílias Fabaceae e Leguminosae. Análises em CCDA das frações oriundas da extração ácido/base das folhas de P. trichophora não apresentaram reação positiva para alcaloides com o reagente Dragendorff. Testes preliminares com a Escherichia coli revelaram o potencial farmacológico da fração acetato de etila das folhas de C. espelina, com 74 % de inibição de crescimento bacteriano, na concentração de 82μg/mL. Esta fração também exibiu forte atividade antioxidante, com IC50 de 5,40 ± 0,16 μg/mL, comparável ao antioxidante comercial ácido ascórbico. Os extratos brutos etanólicos de C. espelina e C. weddellii foram os mais promissores como antioxidantes, com IC50 de 13,21 ± 0,31 e 13,14 ± 0,57 μg/mL, respectivamente. Em bioensaios preliminares com a linhagem tumoral Sarcoma 180, todas as amostras testadas exibiram baixa atividade, apesar da descrição na literatura de atividade antitumoral para os flavonoides isolados.

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Costa, Mariana de Campos da [UNESP]. "Compostos bioativos e atividade sequestrante de radicais livres de quatro cultivares do Coffea arabica L. em diferentes estádios de maturação dos frutos." Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/126534.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Entre as bebibas mais consumidas no Brasil destaca-se o café, um grão pertencente à família Rubiaceae, gênero Coffea. O Brasil produziu em 2014, 45,3milhões de sacas de café. As exportações brasileiras chegaram a aproximadamente 33,36 milhões de sacas, com o faturamento de US 5,98 bilhões. Vários fatores podem influenciar na qualidade da bebida, como a variedade, condições de cultivo, maturação dos frutos, fatores pré e pós-colheita, secagem, torração dos grãos entre outras, Além disso, o café apresenta na sua composição compostos bioativos como ácidos fenólicos, cafeína e trigonelina, que podem auxiliar na prevenção de algumas doenças. O objetivo deste estudo foi quantificar os teores de fenólicos e flavonóides totais, a atividade antioxidante, cafeína e composição de ácidos fenólicos de quatro cultivares de Coffea arabica (Acaiá, Obatã, Catuaí Amarelo, Catuaí Vermelho) durante os estádios de maturação dos frutos (verde, verde-cana, cereja e passa) e do cereja descascado. A atividade antioxidante foi medida pelo método de redução dos radicais DPPH e ABTS; os fenólicos totais pelo método de Folin-Ciocalteu; e os flavonóides totais pela reação colorimétrica com cloreto de alumínio. Os ácidos fenólicos (ácido clorogênico, ácido ferúlico e trigonelina) foram separados e quantificados por HPLC com detector por arranjo de diodos e em coluna de C18. Os cultivares Catuaí Amarelo e Catuaí Vermelho apresentaram os maiores teores de compostos fenólicos totais e flavonoides totais. Os cultivares Acaiá e Obatã apresentaram maior teor de cafeína. Em relação ao ácido clorogênico, maiores concentrações foram observadas nos cultivares Acaiá e Catuaí Vermelho e maior teor de ácifo ferrúlico no cultivar Catuaí Amarelo. Maior atividade antioxidante foi encontrada no cultivar Acaiá e menor, no Obatã. Com a maturação dos frutos há uma diminuição na concentração de cafeína. Maior...
Among the most consumed bebibas in Brazil stands out for coffee, a grain belonging to the Rubiaceae family, genus Coffea. Brazil produced in 2014, 45,3milhões bags of coffee. Brazilian exports reached approximately 33.36 million bags, with the US 5.98 billion revenue. Several factors may influence the quality of the beverage, as the variety, growing conditions, ripening of fruits, factors pre and post-harvest, drying, roasting of the beans among others, also the coffee has in its bioactive composition as phenolic acids, caffeine and trigonelline, which may help prevent some diseases. The objective of this study was to quantify the phenolic content and total flavonoids, antioxidant activity, caffeine and phenolic acids composition of four cultivars of Coffea arabica (Acaiá, Obatã, Catuaí Yellow Catuaí Red) during fruit maturation stages (green, green-cane, cherry and passes) and pulped. Antioxidant activity was measured by the reduction method of DPPH and ABTS radicals; total phenolics by the Folin-Ciocalteu method; and the total flavonoids by colorimetric reaction with aluminum chloride. Phenolic acids (chlorogenic acid, trigonelline and ferulic acid) were separated and quantified by HPLC with diode array detector and a C18 column. The cultivars Catuaí Yellow and Catuaí Red showed the highest levels of total phenolic compounds and total flavonoids. The Acaiá and Obatã cultivars had higher caffeine content. Regarding the chlorogenic acid, higher concentrations were observed in Acaiá and Catuaí Red cultivars and most ácifo ferulic content in Catuaí Yellow. Higher antioxidant activity was found in Acaiá and lower in Obatã. With the ripening of fruits there is a decrease in caffeine concentration. Highest antioxidant activity of coffee fruit is due to the content of chlorogenic acid.

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Silva, Luis Fernando Mercês Chaves [UNESP]. "Estudo sobre a redução do estresse oxidativo em sêmen equino a partir da adição de quercetina nos diluentes de refrigeração e congelação." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/138950.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
O surgimento das biotecnologias aplicadas ao sêmen equino, como a refrigeração e congelação, representaram um grande avanço para equinocultura, principalmente por permitir um melhor aproveitamento do ejaculado, otimizando a utilização de animais considerados geneticamente superiores. Entretanto a aplicação dessas técnicas imprime estresse térmico às células espermáticas, resultando em injúrias físicas e químicas, dentre elas uma elevação significativa na produção de espécies reativas do oxigênio (EROs). Quando em excesso, estes agentes instáveis são capazes de reagir e promover lesão às enzimas, lipídeos de membrana e ácidos nucleicos, reduzindo a viabilidade dos espermatozoides criopreservados. Desta maneira surge a necessidade de se introduzir elementos que desempenhem função antioxidante nos meios de refrigeração e congelação. A quercertina, um polifenol do grupo dos flavonoides, é considerada um poderoso antioxidante por reduzir o surgimento das principais EROs, quelar íons metálicos formadores de radicais livres e estabilizar a peroxidação lipídica. Apesar disto, a eficiência da aplicação deste antioxidante sobre o ejaculado equino durante o processo de criopreservação ainda é controversa e pouco referenciada, sendo necessário mais estudos para que se determine a influência de sua utilização no ejaculado de garanhões durante a refrigeração e congelação.
The emergence of biotechnologies applied to the equine semen as cooling and freezing process represented a major breakthrough for Equine, especially for allowing a better use of the ejaculate, optimizing the use of genetically superior animals. However the application of these techniques induces thermal stress on sperm cells, resulting in physical and chemical injuries, among them a significant rise in the production of reactive oxygen species (ROS). These unstable agents when in excess, are able to react and promote damage to enzymes, lipid membrane and nucleic acids, thereby reducing the viability of cryopreserved sperm. Thus is required to introduce elements that perform antioxidant function in cooling and freezing extenders. The quercertina, a polyphenol of the flavonoids group, is considered a potent antioxidant by reducing the emergence of the main ROS, chelate metal ions producers of free radicals and stabilize the lipid peroxidation. Despite this, the efficiency of application of this antioxidant on the equine ejaculate during the process of cryopreservation is still controversial and poorly referenced, requiring further studies in order to determine if there is influence of their use in the ejaculate of stallions during cooling and freezing.
FAPESP: 2014/01681-4

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Silva, Luis Fernando Mercês Chaves. "Estudo sobre a redução do estresse oxidativo em sêmen equino a partir da adição de quercetina nos diluentes de refrigeração e congelação." Botucatu, 2016. http://hdl.handle.net/11449/138950.

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Orientador: Frederico Ozanam Papa
Resumo: O surgimento das biotecnologias aplicadas ao sêmen equino, como a refrigeração e congelação, representaram um grande avanço para equinocultura, principalmente por permitir um melhor aproveitamento do ejaculado, otimizando a utilização de animais considerados geneticamente superiores. Entretanto a aplicação dessas técnicas imprime estresse térmico às células espermáticas, resultando em injúrias físicas e químicas, dentre elas uma elevação significativa na produção de espécies reativas do oxigênio (EROs). Quando em excesso, estes agentes instáveis são capazes de reagir e promover lesão às enzimas, lipídeos de membrana e ácidos nucleicos, reduzindo a viabilidade dos espermatozoides criopreservados. Desta maneira surge a necessidade de se introduzir elementos que desempenhem função antioxidante nos meios de refrigeração e congelação. A quercertina, um polifenol do grupo dos flavonoides, é considerada um poderoso antioxidante por reduzir o surgimento das principais EROs, quelar íons metálicos formadores de radicais livres e estabilizar a peroxidação lipídica. Apesar disto, a eficiência da aplicação deste antioxidante sobre o ejaculado equino durante o processo de criopreservação ainda é controversa e pouco referenciada, sendo necessário mais estudos para que se determine a influência de sua utilização no ejaculado de garanhões durante a refrigeração e congelação.
Abstract: The emergence of biotechnologies applied to the equine semen as cooling and freezing process represented a major breakthrough for Equine, especially for allowing a better use of the ejaculate, optimizing the use of genetically superior animals. However the application of these techniques induces thermal stress on sperm cells, resulting in physical and chemical injuries, among them a significant rise in the production of reactive oxygen species (ROS). These unstable agents when in excess, are able to react and promote damage to enzymes, lipid membrane and nucleic acids, thereby reducing the viability of cryopreserved sperm. Thus is required to introduce elements that perform antioxidant function in cooling and freezing extenders. The quercertina, a polyphenol of the flavonoids group, is considered a potent antioxidant by reducing the emergence of the main ROS, chelate metal ions producers of free radicals and stabilize the lipid peroxidation. Despite this, the efficiency of application of this antioxidant on the equine ejaculate during the process of cryopreservation is still controversial and poorly referenced, requiring further studies in order to determine if there is influence of their use in the ejaculate of stallions during cooling and freezing.
Mestre

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Costa, Mariana de Campos da. "Compostos bioativos e atividade sequestrante de radicais livres de quatro cultivares do Coffea arabica L. em diferentes estádios de maturação dos frutos /." Araraquara, 2015. http://hdl.handle.net/11449/126534.

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Orientador: Célia Maria de Sylos
Banca: Gerson Silva Giomo
Banca: André Gonzaga dos Santos
Resumo: Entre as bebibas mais consumidas no Brasil destaca-se o café, um grão pertencente à família Rubiaceae, gênero Coffea. O Brasil produziu em 2014, 45,3milhões de sacas de café. As exportações brasileiras chegaram a aproximadamente 33,36 milhões de sacas, com o faturamento de US 5,98 bilhões. Vários fatores podem influenciar na qualidade da bebida, como a variedade, condições de cultivo, maturação dos frutos, fatores pré e pós-colheita, secagem, torração dos grãos entre outras, Além disso, o café apresenta na sua composição compostos bioativos como ácidos fenólicos, cafeína e trigonelina, que podem auxiliar na prevenção de algumas doenças. O objetivo deste estudo foi quantificar os teores de fenólicos e flavonóides totais, a atividade antioxidante, cafeína e composição de ácidos fenólicos de quatro cultivares de Coffea arabica (Acaiá, Obatã, Catuaí Amarelo, Catuaí Vermelho) durante os estádios de maturação dos frutos (verde, verde-cana, cereja e passa) e do cereja descascado. A atividade antioxidante foi medida pelo método de redução dos radicais DPPH e ABTS; os fenólicos totais pelo método de Folin-Ciocalteu; e os flavonóides totais pela reação colorimétrica com cloreto de alumínio. Os ácidos fenólicos (ácido clorogênico, ácido ferúlico e trigonelina) foram separados e quantificados por HPLC com detector por arranjo de diodos e em coluna de C18. Os cultivares Catuaí Amarelo e Catuaí Vermelho apresentaram os maiores teores de compostos fenólicos totais e flavonoides totais. Os cultivares Acaiá e Obatã apresentaram maior teor de cafeína. Em relação ao ácido clorogênico, maiores concentrações foram observadas nos cultivares Acaiá e Catuaí Vermelho e maior teor de ácifo ferrúlico no cultivar Catuaí Amarelo. Maior atividade antioxidante foi encontrada no cultivar Acaiá e menor, no Obatã. Com a maturação dos frutos há uma diminuição na concentração de cafeína. Maior...
Abstract: Among the most consumed bebibas in Brazil stands out for coffee, a grain belonging to the Rubiaceae family, genus Coffea. Brazil produced in 2014, 45,3milhões bags of coffee. Brazilian exports reached approximately 33.36 million bags, with the US 5.98 billion revenue. Several factors may influence the quality of the beverage, as the variety, growing conditions, ripening of fruits, factors pre and post-harvest, drying, roasting of the beans among others, also the coffee has in its bioactive composition as phenolic acids, caffeine and trigonelline, which may help prevent some diseases. The objective of this study was to quantify the phenolic content and total flavonoids, antioxidant activity, caffeine and phenolic acids composition of four cultivars of Coffea arabica (Acaiá, Obatã, Catuaí Yellow Catuaí Red) during fruit maturation stages (green, green-cane, cherry and passes) and pulped. Antioxidant activity was measured by the reduction method of DPPH and ABTS radicals; total phenolics by the Folin-Ciocalteu method; and the total flavonoids by colorimetric reaction with aluminum chloride. Phenolic acids (chlorogenic acid, trigonelline and ferulic acid) were separated and quantified by HPLC with diode array detector and a C18 column. The cultivars Catuaí Yellow and Catuaí Red showed the highest levels of total phenolic compounds and total flavonoids. The Acaiá and Obatã cultivars had higher caffeine content. Regarding the chlorogenic acid, higher concentrations were observed in Acaiá and Catuaí Red cultivars and most ácifo ferulic content in Catuaí Yellow. Higher antioxidant activity was found in Acaiá and lower in Obatã. With the ripening of fruits there is a decrease in caffeine concentration. Highest antioxidant activity of coffee fruit is due to the content of chlorogenic acid.
Mestre

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43

Holasová, Petra. "PSE extrakce rostlinného materiálu pro potravinářské účely." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2009. http://www.nusl.cz/ntk/nusl-216538.

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Flavonoids were identified and quantified in samples of dry leaves of plant Stevia rebaudiana Bertoni. Content of flavonols (kaempherol, quercetin, myricetin, rutin) and flavons (apigenin, luteolin) were compared in three samples (standard leaves of Stevia rebaudiana Bertoni, Stevia rebaudiana Bertoni origin from Ukraine and from Czech republic), that were extracted by three extraction methods (PSE, ultrasonic extraction, Soxhlet extraction) with two polar solvents, methanol and ethanol, in combination with non-polar hexane. Extracts were analyzed by HPLC with detection UV-VIS. Antioxidant activity and total content of flavonoids in extracts were measured by spectrometry. Stable free radical DPPH. was used for determination of scavenging effect in extracts. PSE was the most effective extraction method with this conditions – 120 °C, dynamic mode and with methanol like solvent.

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Chen, Xiao Jia. "Qualitative and quantitative analysis of flavonoids in Epimedium." Thesis, University of Macau, 2007. http://umaclib3.umac.mo/record=b1676776.

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Weigel, Benjamin [Verfasser]. "Biotransformations from and to methylated flavonoids / Benjamin Weigel." Halle, 2017. http://d-nb.info/1139253840/34.

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Zheng, Yuanyuan. "PROTECTION AGAINST ENDOTHELIAL INFLAMMATION BY GREEN TEA FLAVONOIDS." UKnowledge, 2010. http://uknowledge.uky.edu/gradschool_diss/64.

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Endothelial inflammation is a pivotal early event in the development of atherosclerosis. Long term exposure to cardiovascular risk factors will ultimately exhaust those protective anti-inflammatory factors such as the heme oxygenase (HO) system. The HO system plays a critical role in cellular and tissue self-defense against oxidative stress and inflammation. Caveolae are membrane domains and are particularly abundant in endothelial cells, where they are believed to play a major role in the regulation of endothelial vesicular trafficking as well as the uptake of lipids and related lipophilic compounds, possibly including bioactive food components such as flavonoids. Research in this dissertation addresses the role of HO-1 and caveolae on dietary flavonoid epigallocatechin gallate (EGCG) mediated protection against pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) and linoleic acid-induced activation of endothelial cells. The data support the hypothesis that EGCG protects against TNF-α-induced monocyte recruitment and adhesion partially through the induction of HO-1 and bilirubin. The observed anti-inflammatory effects of EGCG are mimicked by the HO-1 inducer cobalt protoporphyrin (CoPP) and abolished by HO-1 gene silencing. Nrf2 is the major transcription factor of phase II antioxidant enzymes including HO-1. Results clearly show that EGCG-induced HO-1 expression and subsequent bilirubin productions are dependent on functional Nrf2. EGCG also can down-regulate the base-line level of caveolin-1. Furthermore, silencing of the caveolin-1 gene can markedly down-regulate linoleic acid-induced COX-2 and MCP-1, indicating that caveolae may be a critical platform regulating inflammatory signaling pathways. Similar to EGCG treatment, silencing of caveolin-1 can also result in the activation of Nrf2, up-regulation of HO-1 and bilirubin. This may be one of the mechanisms to explain the protection effect of caveolin-1 gene silencing against endothelial inflammation. Moreover, EGCG rapidly accumulates in caveolae, which is associated with caveolin-1 displacement from the plasma membrane towards the cytosol. Caveolin-1 gene silencing can significantly reduce the uptake of EGCG in endothelial cells within 30 min. These data suggest that caveolae may play a role in the uptake and transport of EGCG in endothelial cells. These studies provide a novel target through which EGCG functions to protect against inflammatory diseases such as atherosclerosis.

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Porter, Elaine Ann. "Distribution of polyhydroxyalkaloids and flavonoids in the Myrtaceae." Thesis, Birkbeck (University of London), 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.411322.

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Cushnie, T. P. Tim. "Investigation of the antibacterial activity of selected flavonoids." Thesis, Robert Gordon University, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430050.

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Christidou, Maria. "The role of flavonoids on brain tumour invasion." Thesis, King's College London (University of London), 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414780.

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Cox, Carla. "Flavonoids as regulators of amyloid precursor protein processing." Thesis, University of Bath, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.616643.

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Alzheimer’s disease (AD) is a progressive neurodegenerative disorder. Amyloid precursor protein (APP) processing and the subsequent generation of amyloid β (Aβ) are central to the pathogenesis of AD, as soluble, oligomeric Aβ peptides are thought to be the toxic species driving disease progression. Flavonoids, a group of dietary polyphenols, have been shown to possess cognitive health benefits. Epidemiological evidence suggests they could play a role in risk reduction in dementia. In vitro and in vivo reports suggest flavonoids can modulate APP metabolism and Aβ production, although the most effective compounds and the underlying mechanism of action remain unclear. This study identified select flavonoids that were able to reduce amyloidogenic processing in primary cortical neurons at physiologically relevant concentrations. An APP-Gal4 gene reporter assay was characterised for identification of modulators of APP processing in primary neurons. It was tested under physiological conditions, in a pro-oxidant environment or against pathological levels of Aβ production through introduction of a known familial AD (FAD) causing mutation of APP (K595N/M596L). Using this system, five flavonoids were identified that inhibited amyloidogenic APP processing at 100 nM, these were: fisetin, pelargonidin, sinensetin, (-) epicatechin and epigallocatechin. Due to known bioavailability, the catechin family were investigated further and epigallocatechin and (-) epicatechin were confirmed as potent (low nanomolar) inhibitors of amyloidogenic processing. Investigation into the mechanism of action by (-) epicatechin suggested it was likely through indirect BACE1 activity inhibition, independent of BACE1 expression. In addition to activity at APP processing (-) epicatechin also induced extracellular signal-regulated kinase (ERK) activation and transcriptional activity. Investigation of other lead flavonoids also identified fisetin as an inhibitor of ERK-dependent transcriptional activity. This study supports the hypothesis that flavonoids are modulators of APP processing and that they could offer a potential therapy for the prophylaxis of AD.

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Dissertations / Theses on the topic 'Flavonoids'

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