Dissertations / Theses on the topic 'Sesquiterpenes'
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1
Henry, S. G. "Studies towards tricyclic sesquiterpenes." Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603969.
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There has been considerable interest in the synthesis and biological properties of sesquiterpene lactones as a result of their cytotoxic activity. This manuscript describes a concise synthesis of the elemanolide model compound 3.1 and studies towards the synthesis of 8-deoxyvernolepin 1.6. The first chapter will deal with sesquiterpene motifs, culminating in the introduction of elemanolides and eudesmanolides. Isolation and biological activity of elemanolides (particularly vernolepin) will be presented, along with a possible biosynthesis and selected previous syntheses. Chapter two details the role of manganese triacetate in oxidative radical reactions, highlighting the main differences between manganese and tin. A brief outline of work done in our group on oxidative cyclisations with manganese(III) acetate is included, along with examples of tethered cyclisations. Chapter three discusses an enantioselective route to a model compound of 8-deoxyvernolepin 1.6 utilising an enantioselective Diels Alder reaction, followed by attempted 1,3-transpositons of stereochemical information. Chapter four describes a racemic synthetic pathway to both 8-deoxyvernolepin 1.6, the model compound 3.1 and subsequent analogues, using a racemic Diels-Alder reaction, palladium-mediated π-allyl substitution and tin-mediated radical substitution.
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Vieira, Tiago de Oliveira. "Estudos visando à síntese de sesquiterpenos bacanos." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/46/46135/tde-06062016-155559/.
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Nesta tese, efetuamos estudos visando à síntese de sesquiterpenos bacanos, cuja etapa chave consistiu na construção do sistema cis-hidrindânico, através de reação de contração de anel de cis-octalinas e 2-octalonas mediada por trinitrato de tálio (TTN). Apenas as cis-octalinas como, por exemplo, o cis-4a-metil-l,2,3,4,4a,5,8,8a-octahidronaftaleno e o cis-4a, 7-dimetil-l,2,3,4,4a,5,8,8a-octa-hidronaftaleno, foram passíveis de reação de contração de anel em rendimentos satisfatórios; já a cis-5,10-dimetil-l(9)-octal-2-ona levou ao produto de contração em baixo rendimento. Tentamos utilizar a reação de cis-4a-metil-l,2,3,4,4a,5,8,8a-octa-hidronaftaleno com TTN na síntese da nor-baquenolida-A, porém não conseguimos completar a síntese desta, pois não foi possível efetuar a última etapa sintética, nas várias abordagens testadas. Grandes esforços também foram empregados na preparação diastereosseletiva da cis-5,10-dimetil-l(9)-octal-2-ona através de três abordagens diferentes que foram investigadas, sendo duas delas com êxito. Contudo, o baixo rendimento (38%) da etapa de contração de anel da cis-5,10-dimetil-l(9)-octal-2-ona não permitiu a continuação da rota sintética proposta para a baquenolida-A. Também realizamos a resolução cinética de três diferentes cis-octalóis que foram preparados através da reação de Diels-Alder seguida de redução diastereosseletiva - com a lipase Novozym 435, e os produtos resolvidos foram obtidos em excelentes rendimentos isolados (≥ 40% para cada enantiômero) e excelentes excessos enantioméricos (≥ 98%).In this thesis, we have developed studies towards the synthesis of sesquiterpenes bakkanes, which key step consisted on the construction of the cis-hydrindanic system through a thallium(III) mediated ring contraction reaction of cis-decalins and 2-octalones. Only the cis-octalins, such as the 1,2,3,4,4a,5,8,8a-octahydro-4a-methylnaphthalene and the 1,2,3,4,4a,5,8,8a-octahydro-4a,7-dimethylnaphthalene, were able to be ring contracted in satisfactory yields; the 4,4a,5,6,7,8-hexahydro-4a,5-dimethylnaphthalen-2(3H)-one, however, furnished the ring contraction product in low yield. We tried to use the reaction of 1,2,3,4,4a,5,8,8a-octahydro-4amethylnaphthalene with TTN in the synthesis of nor-bakkenolide-A, but we could not accomplish the synthesis because it was not possible to make the last step of the sequence, in all tested approaches. Great efforts were made in the diastereoselective preparation of the 4,4a,5,6, 7 ,8-hexahydro-4a,5-dimethylnaphthalen-2(3H)-one, through three different approaches that were investigated, being two of them with profit. However, the low yield (38%) of the ring contraction reaction of 4,4a,5,6, 7,8-hexahydro-4a,5-dimethylnaphthalen-2(3H)-one, precluded the continuation of the synthetic rout proposed to the bakkenolide-A. We have also performed the kinetic resolution of three different cis-octalols that were prepared through Diels-Alder reaction followed by diastereoselective reduction - with the Novozym 435 lipase, and the resolved products were isolated in excellent yields (≥ 40% for each enantiomer) and excellent ee\'s (≥ 98%).
3
伍冠先 and Koon-sin Ngo. "Synthesis isolation and autoxidation of sesquiterpenes." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31239134.
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Perea, Buceta Jesus E. "Synthetic studies on anislactone-type sesquiterpenes." Thesis, University of Edinburgh, 2007. http://hdl.handle.net/1842/15628.
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Extensive phytochemical studies carried out over the last two decades on plants of the genus Illicium, had led to the isolation and characterization of several anislactone-type sesquiterpenes. The neurotrophic activity of merrilactone A 17, coupled with the structural diversity which could be accessed by further derivatisation of other members, gives this family of secondary metabolites value in the process of discovering novel therapeutic agents to address the molecular causes underlying the progression of neurodegenerative diseases. Additionally, the anislactone-type sesquiterpenes family constitutes an ideal synthetic arena for the development of innovative methods dealing with the construction of highly-functionalised five-membered rings, and the creation of contiguous fully-substituted stereocentres. The thesis presented herein, describes the results obtained in the course of our investigations to lay the foundations of a synthetic program targeting the divergent total syntheses of several members of the anislactone-type sesquiterpenes family, including the novel implementation and limitations associated to a domino oxy-/carbopalladation reaction, which proved to be pivotal in the development of a short route towards the oxa[3.3.3]propellane carbocyclic core of merrilactone A, in addition to the development of a expeditive nine-steps route furnishing the tricyclic core of the anislactone-type sesquiterpenes 14, 15, 16 and 19, in a high overall yield.
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Ngo, Koon-sin. "Synthesis isolation and autoxidation of sesquiterpenes /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B2102103X.
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Sarkar, Purabi. "Studies in the synthesis of sesquiterpenes." Thesis, University of North Bengal, 1992. http://hdl.handle.net/123456789/852.
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Leung, Pou Ian. "Sesquiterpenes emission from common airborne fungal species /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?EVNG%202009%20LEUNG.
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Vaidya, S. P. "Studies in sesquiterpenes: newer perspectives of longifolene." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 1985. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/3238.
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Satyanarayana, N. "Studies in sesquiterpenes (newer aspects of longifolene)." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Poona, 1985. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/3230.
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Selvakumar, N. "Synthetic investigations on terpenoids." Thesis, Indian Institute of Science, 1994. https://etd.iisc.ac.in/handle/2005/110.
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The thesis entitled "Synthetic Investigations on Terpenoids" is divided into two sections. Section 1 deals with the total synthesis of sesquiterpenes belonging to the Zizsene group and Section 2 contains the synthetic investigations on the furanoid dlterpenes of labdane group.
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Selvakumar, N. "Synthetic investigations on terpenoids." Thesis, Indian Institute of Science, 1994. http://hdl.handle.net/2005/110.
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The thesis entitled "Synthetic Investigations on Terpenoids" is divided into two sections. Section 1 deals with the total synthesis of sesquiterpenes belonging to the Zizsene group and Section 2 contains the synthetic investigations on the furanoid dlterpenes of labdane group.
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Araújo, Ana Lucia Santos de Matos. "Estudos sobre a síntese de microbiotol." Universidade de São Paulo, 1999. http://www.teses.usp.br/teses/disponiveis/59/59132/tde-15102002-163623/.
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Neste trabalho descrevemos vários estudos sintéticos realizados com o objetivo de desenvolver um método para a preparação de Microbiotol (1). A estratégia planejada consistiu em preparar o anel ciclopentano que constitui a metade esquerda da fórmula de (1) acima por contração de anel de isoforona (58), e depois juntar uma cadeia aberta que seria posteriormente ciclizada para formar o segundo anel. A contração do anel da isoforona (58) foi realizada de acordo com as reações a seguir: Os compostos de fórmula geral (85) apresenta considerável congestionamento estérico e resistem fortemente à adição de nucleófilos. Neste trabalho desenvolvemos apenas estudos de adição de derivados de levulinato de metila, este mesmo apresentando problemas de reatividade devido a problemas estéricos, e mostramos que este não é o caminho adequado para adicionar um nucleófilo aos compostos (85).In this work we describe several synthetic studies realized with the purpose of developing a method for the preparation of Microbiotol (1). Our synthetic strategy consisted of preparing the ciclopentane ring which is the left moiety of structure (1) by a ring contraction , starting from isophorone (58), and then add an open chain which would be cyclized to for second ring. The ring contraction was realised according to the following steps. The compounds of general structure (58) have a considerable steric hindrance and are strongly resistant to the addition of a nucleophile. In this work we used only derivatives of methyl levulinate as nucleophiles ; these substrates are themselves sterically hindered, and we showed that this is not the appropriate method to add a nucleophile to compounds (85).
13
Ahuja, Jaimala R. "Synthesis of optically active sesquiterpenes and α-arylpropanoic acids." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 1991. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2990.
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Ahuja, J. R. "Synthesis of optically active sesquiterpenes and α-arylpropanoic acids." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 1991. https://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/5942.
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Janse, Van Rensburg Daniel Francois. "The biological properties of three trichothecene mycotoxins produces by fusaris." Master's thesis, University of Cape Town, 1986. http://hdl.handle.net/11427/27209.
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The highly toxic fungal metabolite, neosolaniol monoacetate, was isolated and purified from cultures of Fusarium sambucinum. Since little is known about its toxic properties, the biological effects of this trichothecene were compared to those caused by diacetoxy-scirpenol in male Wistar rats. The lesions caused by the two toxins were very similar. Chronic exposure to either toxin led to a significant decrease (P<0.05) in red blood cell counts and a significant increase (P<0.05) in platelet size. The major pathological lesions observed were atrophy of the actively dividing cells of the bone marrow, thymus, spleen and lymph nodes. The reported species difference in T-2 toxin toxicity was investigated by determining the deacylation rate of T-2 toxin to HT-2 toxin, one of the first steps in the detoxification of this trichothecene. The high deacylation rate catalysed by rat microsomes correlated with the low sensitivity of this species to T-2 toxin, whereas the low deacylation rates with cat and monkey microsomes agreed with their high sensitivity. In contrast to this, the apparently high toxicity of T-2 toxin to humans does not correlate with the high deacylation rate observed in human hepatic microsomes. Involvement of the UDP-glucuronyltransferases in the detoxification of T-2 toxin was studied with rat and pig hepatic microsomes. T-2 toxin and two of its metabolites, HT-2 toxin and T-2 tetraol, did not appear to act as substrates for these enzymes under the in vitro conditions used.
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Greenhagen, Bryan T. "Origins of isoprenoid diversity a study of structure-function relationships in sesquiterpene systems /." Lexington, Ky. : [University of Kentucky Libraries], 2003. http://lib.uky.edu/ETD/ukyplph2003d00093/Greenhagen.pdf.
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Thesis (Ph. D.)--University of Kentucky, 2003.Title from document title page (viewed onJune 1, 2004). Document formatted into pages; contains x, 145 p. : ill. Includes abstract and vita. Includes bibliographical references (p. 126-143).
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Fehlberg, Isley. "Terpenos e fenilpropanoides de Myrcia guianesis (Myrtaceae)." reponame:Repositório Institucional da UFBA, 2013. http://www.repositorio.ufba.br/ri/handle/ri/9749.
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CAPES
Os extratos etanólicos obtidos a partir das folhas e do caule de Myrcia guianensis foram particionados sequencialmente com hexano, diclorometano ou clorofórmio e acetato de etila. As fases em diclorometano e acetato de etila das folhas, bem como, as fases clorofórmica e hexânica do caule foram submetidas a vários procedimentos cromatográficos em coluna e em camada delgada preparativa. A partir da fase diclorometânica das folhas foram obtidos os sesquiterpenos 5-(6-metilheptan-2-ona)-biciclo-[3.1.0]-hexan-3-ona, 6-metil-5-(2-hidroxi-3-cloro-5-metilfenil)heptan-2-ona, 6-metil-5-(2-hidroxi-5-metilfenil)heptan-2-ona (sesquichamaenol) e oplopanona, sendo os dois primeiros inéditos. O estudo da fase acetato de etila resultou no isolamento do ácido gálico e dos flavonóides quercetina, quercitrina e guaijaverina. Da fase hexânica do caule foram isolados um sesquiterpeno aromático inédito do tipo cadinano, 7-hidroxi-5-isopropil-3,8-dimetil-2-metóxi-1,4-naftoquinona, e os esteróides β–sitosterol e seu derivado glicosilado, o daucosterol. A partir da fase clorofórmica foi isolada a lignana (-)-(8R,8’R)-9,9’-di-O-(E)-feruloil-secoisolariciresinol e sete triterpenos, sendo eles, ácido maslínico, ácido estáclico A e seu novo derivado p-cumárico, ácido 3β-trans-p-oxicumaroil-2α,23,29-triidroxi-olean-12-en-28-oico, ácido arjunólico e os derivados, ácido 3β-trans-p-oxicumaroil-2α,23-diidroxi-olean-12-en-28-oico, ácido 23-trans-p-oxicumaroil-2α,3β-diidroxi-olean-12-en-28-oico e o novo ácido 3β-trans-feruloil-2α,23-diidroxi-olean-12-en-28-oico. As estruturas destas substâncias foram determinadas e/ou identificadas por análises de Espectrometria no Infravermelho, Espectrometria de massas, RMN de 1H e 13C, DEPT 135º, HMBC, HMQC, COSY e NOESY.
Salvador
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Silva, Waldeyr Mendes Cordeiro da. "In silico reconstruction of sesquiterpenes metabolic network of Copaifera multijuga Hayne." reponame:Repositório Institucional da UnB, 2018. http://repositorio.unb.br/handle/10482/34208.
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Tese (doutorado)—Universidade de Brasília, Departamento de Biologia Celular, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Biologia Molecular, 2018.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) e Fundação de Apoio à Pesquisa do Distrito Federal (FAPDF).
Comumente chamada de “copaíba”, a Copaifera multijuga Hayne (CmH) é uma planta do gênero Copaifera (Leguminosae-Caesalpinoideae) que ocorre na Amazônia brasileira. Extraído do tronco das árvores, o óleo-resina de Copaifera spp. é amplamente utilizado por povos indígenas da região amazônica na medicina popular e tem alto potencial associado a aplicações biotecnológicas como agente antimicrobiano, anti-inflamatório, antitumoral, antinociceptivo, antileishmanial e cicatrizante. O óleo-resina de Copaifera spp. é composto por ácidos resinosos e compostos voláteis, principalmente sesquiterpenos e diterpenos Neste trabalho, sesquiterpenos do óleo-resina da CmH, cenários biológicos para sua biossíntese e seus mecanismos químicos foram coletados de vários estudos. Com base nessa coleta de dados, em dados de um transcritoma da CmH e em métodos e ferramentas computacionais, foi reconstruída in silico uma rede metabólica de sesquiterpenos de Copaifera multijuga Hayne (CmH). Esta rede metabólica é uma compilação de reações enzimáticas cobrindo mecanismos de ciclização, compostos preditos e cenários biológicos para a biossíntese. Os resultados foram convenientemente armazenados em um banco de dados em grafos projetado especificamente para esta finalidade, tornando-se localizáveis, acessíveis, interoperáveis e reutilizáveis. O workflow utilizado para a reconstrução in silico funciona para múltiplos organismos, bem como pode ser adaptado para diferentes tipos de mecanismos químicos alterando o conjunto de regras de gramática de grafos.
Ordinarily named “copaiba”, the Copaifera multijuga Hayne (CmH) is a plant of Copaifera genus (Leguminosae-Caesalpinoideae) occurring in the Brazilian Amazon. Exuded from the trunk of trees, the oil-resin of Copaifera spp. is widely used by indigenous people from the Amazon region for healing and in folk medicine, and it has high associated potential biotechnological applications, such as antimicrobial, anti-inflammatory, antitumor, antinociceptive, antileishmanial and healing. The oil-resin of Copaifera spp. is composed of resinous acids and volatile compounds, mainly sesquiterpenes and diterpenes In this study, a range of CmH oil-resin sesquiterpenes, biological scenarios for their biosynthesis, and its chemical mechanisms were collected from several studies. Based on this data collection, on CmH transcriptome data, and on computational methods and tools, an in silico sesquiterpene metabolic network of Copaifera multijuga Hayne (CmH) was reconstructed. The resulting sesquiterpene metabolic network of CmH is a compilation of reactions covering cyclization mechanisms, predicted compounds, and biological scenarios for the biosynthesis. These results were suitably stored in a graph database designed for it, and they became findable, accessible, interoperable, and reusable. The workflow for the in silico reconstruction can be used for multiple organisms as well as graph grammar rules can be added or removed to achieve different types of chemical mechanisms.
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Pitaval, Anthony. "Gold catalysis for the synthesis of protoilludane sesquiterpenes and other cyclic systems." Doctoral thesis, Universitat Rovira i Virgili, 2014. http://hdl.handle.net/10803/145765.
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Homogeneous gold catalysis emerged as a powerful tool in organic chemistry, offering new perspectives for the synthesis of natural products. In this Doctoral Thesis, I present the application of the cycloisomerization of substituted alkynes with vinylcyclopropanes towards the synthesis of Repraesentin F. As an extension of this methodology, I studied the cycloisomerization of allenes with vinylcyclopropanes aim at constructing the carbon skeleton of several sesquiterpinoids belonging to the protoilludane family. In addition to these projects, I revisited the cycloisomerization of 1,6-enynes that does not proceed by 1,5-migration of alkoxy group at the propargylic position. The mechanism of this reaction was studied by deuteration of the alkyne terminus y appeared to be an endo-type single cleavage rearrangement.La catálisis homogénea con oro ha emergido como una poderosa herramienta en síntesis orgánica, dando a lugar muchosnuevosmétodospara la síntesis de productos naturales. En esta Tesis Doctoral, presentolaaplicación de la cicloisomerización de alquinos sustituidos con vinilciclopropanospara la síntesis de la repraesentina F. Como extensión de estas investigaciones, estudié la cicloisomerización de alenos con vinilciclopropanos con el objetivo de construir el esqueleto de varios sesquiterpenoides de la familia de los protoilludanos. Además de estos proyectos, he re-visitado la cicloisomerización de 1,6-eninos en la que no ocurre una 1,5-migración de grupos OR en posición propargílica. El mecanismo de la reacción se estudió por deuteración del alquino terminal, resultando ser un reordenamiento de tipo endopor ruptura simple.
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Natchus, Michael George. "[4+1] cyclopentene annulation in the total synthesis of pentalenene type sesquiterpenes." Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/50070.
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The generality of the [4+1] cyclopentene annulation was demonstrated by the total synthesis of (±)-pentalenene and its C-9 epimer which were prepared in a stereocontrolled manner in analogy with the synthesis of (±)-isocomene, (±)-hirsutene and (±)-pentalenic acid. The key features of this synthesis involved preparation of acid 161, its conversion to diazoketone 148, intramolecular cyclopropanation of this substance to vinylcyclopropane 163 and the vinylcyclopropane-cyclo pentene rearrangement of several derivatives of 195 to triquinanes 147, 146, 197, and 204. A detailed study of temperature, conformation, and electronic effects on the diradical scission of vinylcyclopropanes of type 195 was carried out under pyrolytic conditions. Conclusive results regarding conformational stability at C-9 were also attained and exploited in the context of stereocontrol at this center. As a result of this synthesis, several new methods of functional transformations emerged, such as the selective reduction of conjugated esters and a new method of preparation of enolethers from carboxylic acids.Master of Science
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Sy, Lai-king. "Structure elucidation and oxidation chemistry of natural products /." Hong Kong : University of Hong Kong, 1998. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19737300.
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Avila, Renata Couto. "Resist?ncia clonal ? Thaumastocoris peregrinus e caracteriza??o qu?mica por CG/EM de ?leo essencial de eucalipto." UFVJM, 2016. http://acervo.ufvjm.edu.br/jspui/handle/1/1344.
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Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG)
Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq)
Por causa da introdu??o de pragas ex?ticas, as planta??es de Eucalipto est?o sofrendo com consider?veis perdas na produ??o por todo o territ?rio brasileiro. Uma dessas pragas foi detectada em 2008 e ? conhecida como percevejo bronzeado (Thaumastocoris peregrinus). Essa praga de origem Australiana se espalhou rapidamente pelas planta??es de eucalipto no pa?s por causa da falta de seu inimigo natural. Ainda n?o foi encontrado um controle eficaz para o percevejo bronzeado. Para se conseguir a certifica??o florestal, n?o ? recomendado o uso de inseticidas qu?micos ou sint?ticos. Uma das alternativas para o controle desse inseto ? a detec??o e utiliza??o de gen?tipos resistentes nas planta??es e a utiliza??o de bioinseticidas a partir de ?leos essenciais. Para essa constata??o se faz necess?rio testes de resist?ncia nos gen?tipos a fim de encontrar as ideais para os plantios. No laborat?rio de Biotecnologia Florestal da UFVJM foi realizado teste de sobreviv?ncia e de n?o-preferencia alimentar em 27 clones comerciais da empresa Gerdau LTDA e de indiv?duos de Eucalyptus camaldulensis e Corymbia. citriodora, a fim de identificar o n?vel de resist?ncia e suscetibilidade entre os mesmos. Para as duas vari?veis foram considerados os gen?tipos C. citriodora e os clones C4, C11, C24, C25, C27 e C17 como sendo altamente suscept?veis em rela??o aos demais, e os clones C1, C15, C20, C21 e C13 como sendo os mais resistentes em rela??o aos demais. Ap?s a caracteriza??o dos clones foram extra?dos os ?leos essenciais de 3 clones resistentes, 3 suscept?veis e de indiv?duos de E. camaldulensis. Nos ?leos extra?dos foram encontrados compostos que s?o descritos para o controle de diversos insetos, como 1,8 cineol e linalool. Esses compostos comprovam o potencial inseticida dos ?leos essenciais de eucalipto.
Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016.
Because of the introduction of exotic pests, these plantations are suffering considerable losses in production throughout the Brazilian territory. One such pest was detected in 2008 and is known as Bronze bug. This Australian origin worm spread rapidly through the Eucalyptus plantations in the country because of the lack of their natural enemy. We have not yet found an effective control for Bronze bug. To achieve forest certification is not recommended the use of chemical insecticides. One of the alternatives to control this insect is the detection and use of resistant genotypes in plantations and the use of biopesticides from essential oils. For this finding is necessary stress tests in genotypes in order to find the ideal for plantations. In laboratory UFVJM Forest Biotechnology was held survival test and non-food preference in 27 commercial clones of Gerdau LTDA and E. camaldulensis individuals and C. citriodora in order to identify the level of resistance and susceptibility among thereof. For the two variables were considered the genotypes E. Citriodora, C4, C11, C24, C25, C27 and C17 as the most susceptible in relation to others and the clones C1, C15, C20, C21 e C13 as the toughest in relation to others After the characterization of the clones, have been derived the essential oils of three resistant clones, three susceptible clones and E. camaldulensis. In extracted oils, it have been found many compounds that are described to control various insects, as 1,8 cineol and linalool. These compounds show potential insecticide essential oils of Eucalyptus.
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Ferrer, Cabrera Sofia. "Gold Catalysis: From Fundamentals to the Synthesis of Bullvalenes and Naturally Occurring Sesquiterpenes." Doctoral thesis, Universitat Rovira i Virgili, 2018. http://hdl.handle.net/10803/664723.
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La tesi es basa en el desenvolupament de noves transformacions catalitzades per or(I) per construir estructures moleculars complexes i la seua aplicació en metodologia i síntesi total de productes naturals. També s’han realitzat investigacions organometàl•liques en sistemes d’or(I) i estudis mecanístics a través de càlculs DFT.
La primera síntesi total del producte natural repraesentin F, sesquiterpè aïllat del fong Lactarius repraesentaneous, que posseeix activitat biològica relacionada amb la regulació del creixement de plantes, ha sigut completada en 16 passes i 2% rendiment global. La preparació d’aquesta molècula va permetre la reassignació de la seua estructura. El pas clau de la síntesi constitueix una nova reacció en cascada catalitzada per or(I) que involucra una ciclació d’ení/expansió d’anell/reacció Prins del ciclopropilení adequat per construir l’atípic esquelet tricíclic amb fusió anti de la molècula en un pas, utilitzant baixes càrregues de catalitzador (0.5%). El mecanisme d’aquest pas va ser estudiat mitjançant càlculs DFT.
Una metodologia eficient per a la síntesi de barbaralones 1-sustituides a partir de substrats 7-etinil-1,3,5-cicloheptatrié mitjançant una ciclació oxidant catalitzada per or(I) ha sigut desenvolupada. Aquesta constitueix una de les síntesis mes curtes (2 passes), suau i eficient (rendiments bons-excel•lents) de barbaralones fins el moment. Esta metodologia va simplificar la preparació de molècules fluxionals relacionades, com les bullvalones o els bullvalens, i va permetre accés a estructures complexes tipus caixa.
Estudis organometàl•lics han sigut realitzats amb finalitat d’aclarir el paper dels acetilurs d’or(I) i complexes σ,π-dinuclears d’or(I) en reaccions d’enins. Les investigacions mostraren que ambdues especies derivades de 1,6-enins no donaven lloc a productes de ciclació inclús en condicions de temperatures extremes, a mes, els últims resultaren ser pobres catalitzadors en aquestes transformacions. Els resultats van confirmar que dites especies no son intermedis catalítics en reaccions d’enins. Les observacions experimentals van ser suportades per estudis computacionals.La tesis se basa en el desarrollo de nuevas transformaciones catalizadas por oro(I) para construir estructuras moleculares complejas y su aplicación en metodología y síntesis total de productos naturales. También se han realizado investigaciones organometálicas en sistemas de oro(I) y estudios mecanísticos a través de cálculos DFT. La primera síntesis total del producto natural repraesentin F, sesquiterpeno aislado del hongo Lactarius repraesentaneous, que posee actividad biológica relacionada con la regulación del crecimiento de plantas, ha sido completada en 16 pasos y 2% rendimiento global. La preparación de esta molécula permitió la reasignación de su estructura. El paso clave de la síntesis constituye una nueva reacción en cascada catalizada por oro(I) que involucra una ciclación de enino/expansión de anillo/reacción Prins del ciclopropilenino adecuado para construir el atípico esqueleto tricíclico con fusión anti de la molécula en un paso, usando bajas cargas de catalizador (0.5 mol%). El mecanismo del paso clave fue estudiado mediante cálculos DFT. Una metodología eficiente para la síntesis de barbaralonas 1-sustituidas a partir de sustratos 7-etinil-1,3,5-cicloheptatrieno a través de una ciclación oxidante catalizada por oro(I) ha sido desarrollada. Ésta constituye una de las síntesis más cortas (2 pasos), suave y eficiente (rendimientos buenos-excelentes) de barbaralonas hasta el momento. Esta metodología simplificó la preparación de moléculas fluxionales relacionadas, como las bullvalonas o bullvalenos, y permitió acceso a estructuras complejas tipo caja. Estudios organometálicos han sido realizados con finalidad de esclarecer el papel de acetiluros de oro(I) y complejos σ,π-dinucleares de oro(I) en reacciones de eninos. Las investigaciones mostraron que ambas especies derivadas de 1,6-eninos no daban lugar a productos de ciclación incluso en condiciones de temperaturas extremas, además los últimos resultaron ser pobres catalizadores en estas transformaciones. Los resultados confirmaron que dichas especies no son intermedios catalíticos en reacciones de eninos. Las observaciones experimentales fueron soportadas por estudios computacionales.
The present thesis relies on the development of novel gold(I)-catalyzed transformations for the construction of complex polycyclic frameworks and their application to methodology and total synthesis of natural products. Organometallic investigations in gold(I) systems and mechanistic studies through DFT calculations have been also performed. The first total synthesis of the natural product repraesentin F, a sesquiterpene isolated from the fungus Lactarius repraesentaneous which possesses biological activity related to the regulation of plant growth, has been accomplished in 16 steps and 2% overall yield. The synthetic preparation of this molecule allowed its structure reassignment. The key step of the synthesis features a novel cascade reaction involving a gold(I)-catalyzed tandem enyne cyclization/ring expansion/Prins reaction of the appropriate cyclopropylenyne substrate to build the atypical anti-ring fused tricyclic skeleton of the molecule in one step, using a remarkably low 0.5 mol% of catalyst loading. The mechanism of this key transformation was studied through DFT calculations. An efficient methodology for the synthesis of 1-substitued barbaralones from 7-ethynyl-1,3,5-cycloheptatriene substrates via a gold(I)-catalyzed oxidative cyclization has been developed. It constitutes one of the shortest (2 steps), mildest and most efficient synthesis (good to excellent yields) of barbaralones to date. This methodology simplified the synthesis of related fluxional molecules such as bullvalones and bullvalenes and allowed access to complex cage-type structures. Organometallic studies to shed light on the role of σ-monogold and σ,π-digold alkyne complexes in gold(I)-catalyzed reactions of enynes have been performed. The investigations showed that gold(I) acetylides and σ,π-digold(I) alkyne complexes derived from 1,6-enynes fail to cyclize under temperature demanding conditions, being the latest poor catalysts in these transformations. The results confirmed that the aforementioned species are not catalytic intermediates; rather, these complexes are “dead ends” in catalytic reactions of enynes. Computational studies fully supported the experimental observations.
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Sakulyanontvittaya, Tanarit. "Secondary organic aerosol from sesquiterpenes and other biogenic emissions in the United States." Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3303842.
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Rtimi, Aboaleid Ali M. "Chemistry of Bicyclic Sesquiterpenes Isolated from Dittrichia graveolens L. Greuter in Western Australia." Thesis, Curtin University, 2016. http://hdl.handle.net/20.500.11937/57105.
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The chemistry of natural products of Dittrichia graveolens growing in Western Australia (Balingup) was investigated. These compounds were extracted using a rapid extraction technique using ethanol and aqueous solutions. The bioactivity of the extracted bicyclic sesquiterpenes acid was investigated on alfalfa seed germination. The isolated compounds costic and ilicic acid were used as starting material in semisynthesis of new compounds including new natural products.
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Al-Lami, Naeemah. "Synthesis of nitrogen-containing bicyclic sesquiterpenes as potential transition state inhibitors of aristolochene synthase." Thesis, Cardiff University, 2013. http://orca.cf.ac.uk/53674/.
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Aristolochene synthase from Penicillium roqueforti(PR-AS) is sesquiterpene synthase that catalyses the Mg2+-dependent conversion of farnesyl diphosphate FDP to (+)-aristolochene. Through the use of site directed mutagenesis, fluorinated FDPs and an aza-analogue of the eudesmane cation, the reaction was previously shown to involve germacrene A and eudesmane cation as intermediates. The subsequent series of rearrangements that transform the eudesmane cation to (+)-aristolochene have not been investigated previously. To probe the carbocationic nature of these 1,2-hydride and methyl shifts, new aza-analogues were designed to mimic the geometric and electrostatic properties of postulated carbocation intermediates in the catalytic mechanism of PR-AS. Here is described the synthesis of both enantiomers of 10-aza-eremophilane in enantiomerically pure from the common precursor (4S)-limonene oxide and their analysis as inhibitors of PR-AS. The synthesis of (7R,4S,5S)-10-aza-eremophilane cation was accomplished in 8 steps, starting from a known keto ester that in turn was obtained by degradation of (-)-limonene oxide. An identical synthetic protocol was repeated from (4R)-limonene oxide to give the enantiomer of 10-aza-eremophilane cation. Inhibition studies with compound (7R,4S,5S)-10-aza-eremophilane indicated that this ammonium salt acted as a moderate competitive inhibitor of PR-AS (Ki = 38 μM), and showed that eremophilane cation is likely a true intermediate on the pathway from FDP to aristolochene during PR-AS catalysis. The inhibition potency of 10-aza-eremophilane was increased by the addition of diphosphate PPi (Ki = 2.9 μM). This synergetic kinetic effect suggests that the possible involvement of PPi as a stabilizing anion for the eremophilane carbocation in PR-AS biosynthesis. Inhibition studies of the enantiomer of (7R,4S,5S)-10-aza-eremophilane cation, (7S,4R,5R)-10-aza-eremophilane cation, which has incorrect stereocenteres, with PR-AS indicated that this ammonium salt was a poor inhibitor of PR-AS (Ki = 1.03 mM). The data obtained for this compound highlight the chiral environment of the active site of PR-AS, and more importantly supports the postulate that terpene synthases form a product-like contour at their active site that steers the carbocationic cascade catalyzed by PR-AS toward the production of a single enantiomer. iv In the second part of the present work, progress was made towards the stereoselective synthesis of 5-aza-eudesmane cation. This teriary amine is a structural mimic of the 5-eudesmane carbocation, another putative intermediate in the reaction cascade catalysed by PR-AS. However, this tertiary amine was not obtained with desired stereochemistry, nevertheless, two diastereoisomers of the desired compound were obtained.
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Tselanyane, Malefa Lydia. "The isolation, characterization and antiplasmodial activity of two novel dimeric sesquiterpenes from Dicoma anomala." Doctoral thesis, University of Cape Town, 2006. http://hdl.handle.net/11427/3302.
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Includes bibliographical references (leaves 180-208).The study investigates the antimalarial potential of a Southern African traditional medicinal plant, Dicoma anomala (Sond.). The plant is used to treat a variety of treatments including fevers. The extracts of the leaves and twigs have been reported to treat malaria and fever but the treatments with the roots are unrelated to malaria.
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Wei, Lai. "Asymmetric organocatalysis in the Michael reaction of cyclic α-alkyl ketones : enantioselective synthesis of suberosanes and succinimides." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS325.
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La découverte des activités cytotoxiques impressionnantes des subérosanes, des sesquiterpènes d’origine marine isolées dès 1996 de la gorgone Subergorgia suberosa, ainsi que leurs structures tricycliques complexes possédant jusqu’à cinq centre stéréogènes contigus dont un centre quaternaire central, ont fait de ces molécules des cibles de choix tant pour les acteurs de la chimie médicinale que pour ceux travaillant dans le domaine de la synthèse totale. Enfin, une molécule d’origine synthétique « simplifiée » de cette famille, la nor-subérosénone, a également montré des activités cytotoxiques remarquables. Les quantités disponibles de ces produits d’intérêt pharmacologique étant infimes dans le milieu marin, notre équipe s’est intéressée précédemment à la synthèse et à l’évaluation biologique de plusieurs représentants de cette famille de produits naturels et de leurs antipodes permettant de décrire leurs configurations absolues ainsi qu’aux nor-subérosénone et nor-subérosanone d’origine synthétique. L’étape clef de ces synthèses faisant appel à une réaction de Michael asymétrique utilisant un inducteur chiral stœchiométrique peu onéreux et disponible sous ses deux formes antipodales a permis d’obtenir pour la première fois, en version énantiosélective, plusieurs représentants de cette famille de façon concise. Nous décrivons dans ce manuscrit comment nous sommes passés d’une telle réaction de Michael « stœchiométrique » à un processus organocatalysé asymétrique impliquant un système catalytique qui après développement s’est montré efficace et peu coûteux permettant de réduire encore le nombre d’étapes de ces synthèses et d'accroitre l'économie d'atomes, vers une chimie plus respectueuse de l’environnement. Les améliorations apportées aux synthèses précédemment réalisées au sein de notre équipe, et notamment à une cyclisation originale catalysée au triflate d’argent, ont permis de réaliser les synthèses par la voie « stœchiométrique » de nor-subérosanes avec une grande efficacité. La (+)-nor-subérosénone a été obtenue en vingt étapes et 19.29% de rendement global (vs dix-neuf étapes et 4.65% de rendement global précédemment) et la (±)-nor-subérosanone en dix-neuf étapes et 25.06% de rendement global (vs dix-huit étapes et 8.85% de rendement global précédemment). Le succès de la voie organocatalysée a enfin permis de synthétiser la (+)-nor-subérosénone en dix-huit étapes et 19.76% de rendement global (vs dix-neuf étapes et 4.65% de rendement global). Nous avons enfin ouvert la voie à la synthèse potentielle d’épimères des subérosanes via une mise au point de l’addition organocatalysée de Michael de cétone cycliques alpha-méthylées sur les maleimides. Divers maléimides se sont avérés être des électrophiles appropriés dans ce processus, délivrant principalement les adduits attendus portant la stéréodiade centre quaternaire-centre tertiaire adjacents avec des rendements modérés à excellents (39 à 94%) et des énantiosélectivités bonnes à excellentes (75 à 99% ee) dans des conditions réactionnelles faisant intervenir l’activation par les micro-ondes. Des conditions réactionnelles ont été optimisées pour réduire au maximum les diastéréomères et les régioisomères correspondants ainsi que les produits secondaires d’aza-Michael. Ce travail s’inscrit dans le domaine plus vaste et très compétitif de la formation organocatalysée énantiosélective, en une seule étape, d’enchaînement de centre stéréogènes carbonés quaternaire et tertiaireThe discovery of the impressive cytotoxic activities of the subterranean, sesquiterpenes of marine origin isolated in 1996 from the gorgon Subergorgia suberosa, as well as their complex tricyclic structures with up to five contiguous stereogenic centers including a central quaternary center, made these molecules choice targets for both those involved in medicinal chemistry and those working in the field of total synthesis. Finally, a molecule of "simplified" synthetic origin of this family, nor-suzerenone, has also shown remarkable cytotoxic activities. As the quantities available for these products of pharmacological interest are minimal in the marine environment, our team was interested previously in the synthesis and the biological evaluation of several representatives of this family of natural products and their antipodes allowing to describe their absolute configurations as well as nor-suzerenone and nor-suerosanone of synthetic origin. The key step in these syntheses, using an asymmetric Michael reaction using a low-cost stoichiometric chiral inducer available in its two antipodal forms, made it possible to obtain for the first time, in enantioselective version, several representatives of this family in a way that concisely. We describe in this manuscript how we went from such a "stoichiometric" Michael reaction to an asymmetric organocatalytic process involving a catalytic system that after development proved effective and inexpensive enough to further reduce the number of stages of these syntheses and to increase the economy of atoms, towards a chemistry more respectful of the environment. The improvements made to syntheses previously carried out within our team, and in particular to an original cyclization catalyzed with silver triflate, made it possible to synthesize by the "stoichiometric" way of nor-subterraneans with a great efficiency. (+) - nor-suzerenone was obtained in twenty steps and 19.29% overall yield (vs nineteen stages and 4.65% overall yield previously) and the (±) -nor-suerosanone in nineteen stages and 25.06 % overall return (vs eighteen steps and 8.85% overall return previously). The success of the organocatalyzed route eventually allowed to synthesize (+)-nor-suberosenone in eighteen stages and 19.76% overall yield (vs nineteen stages and 4.65% overall yield). Finally, we have opened the way for the potential synthesis of epimers of suberosanes via a development of organocatalyzed Michael addition reaction of alpha-methylated cyclic ketones to maleimides. Various maleimides have been shown to be suitable electrophiles in this process, mainly delivering the expected adducts carrying the adjacent tertiary center-tertiary center stereodiade in moderate to excellent yields (39 to 94%) and good to excellent enantioselectivities (75 to 99% ee) under reaction conditions involving activation by microwaves. Reaction conditions were optimized to minimize corresponding diastereomers and regioisomers as well as aza-Michael by-products. This work is part of the larger and highly competitive field of one-step enantioselective organocatalyst formation of quaternary and tertiary carbon-based stereogenic centers
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Boyes, R. H. O. "The resolution of 3-Methyl-1-pentyn-4-ol and synthetic approaches to two sesquiterpenes." Thesis, University of Southampton, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356526.
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Ham, Won-hun. "Total synthesis of the marine sesquiterpenes (±) dactylol and (±)-africanol : a synthetic approach toward (±)-neolemnanyl acetate /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487266011222592.
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Hodges, Stephen Lee. "The Synthesis of Hindered Aliphatic Ketones for the Future Production of Spiro [4.5] Decane Sesquiterpenes." W&M ScholarWorks, 1986. https://scholarworks.wm.edu/etd/1539625343.
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Pascoa, Henrique. "Desenvolvimento e caracterização de microemulsão à base de óleo de sucupira (P. emarginatus Vog. Fabaceae) e avaliação da atividade antiinflamatória tópica." Universidade Federal de Goiás, 2012. http://repositorio.bc.ufg.br/tede/handle/tede/7384.
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Pterodon emarginatus, popularly known as Sucupira Branca is a native species found in the Brazilian Savannahs in states of Goiás, Minas Gerais, São Paulo, Mato Grosso do Sul. Several studies have confirmed their therapeutic activities as antiinflammatory, antinociceptive, analgesic, antimicrobial, among others. The aim of this study was to develop a microemulsion with topical anti-inflammatory activity from the fixed oil obtained by cold pressing of the fruits of sucupira and additionally evaluate the topical anti-inflammatory activity using the same model of ear edema induced by croton oil. Initially, we made the physical-chemical and chemical composition of vegetable raw material. Using gas chromatography coupled with mass detector was possible to identify the presence of sesquiterpenes such as -caryophyllene and - humulene, with known anti-inflammatory pharmacological activity. The calculation of HLB value required by the oil and tests for determining the surfactant system has enabled the formulation of a microemulsion system using the surfactant/cosurfactant Ultramona® R-540/propyleneglycol, oil sucupira and water proportions 15:10:75 respectively. Stability tests have shown that the formulation when stored in the refrigerator (5±2°C) or room temperature (25±2°C) w ere stable for 30 days with no significant alterations in their physical and chemical parameters. The antiinflammatory activity of oil and formulating show statistical significance when compared to the respective negative controls with p <0.001 for both. The microemulsion presented an effective dosage form for this activity showing great potential for increasing the permeability of the skin oil sucupira confirming the possibility of obtaining a topical herbal medicine with anti-inflammatory action.
Pterodon emarginatus Vogel, conhecida popularmente como sucupira branca, é uma espécie arbórea nativa do cerrado brasileiro encontrada nos estados de Goiás, Minas Gerais, São Paulo e Mato Grosso do Sul. Vários estudos comprovam suas atividades terapêuticas como antiinflamatório, antinociceptivo, analgésica, antimicrobiana, entre outros. O objetivo desse trabalho foi desenvolver uma microemulsão a partir do óleo fixo da sucupira obtido por prensagem à frio de seu frutos e adicionalmente avaliar a atividade antiinflamatória tópica da mesma utilizando o modelo de edema de orelha induzido por óleo de cróton. Inicialmente foi feita a caracterização físico-quimica e da composição química da matéria-prima vegetal. Através de cromatografia gasosa acoplada a detector de massas foi possível identificar a presença de sesquiterpenos como -cariofileno e -humuleno, com conhecida atividade farmacológica antiinflamatória. O cálculo do valor de EHL requerido pelo óleo e ensaios de determinação do sistema tensoativo possibilitou a formulação de uma microemulsão utilizando o sistema tensoativo/cotensoativo Ultramona® R-540/propilenoglicol, o óleo de sucupira e água nas proporções 15:10:75, respectivamente. Ensaios de estabilidade demonstraram que a formulação quando acondicionada em geladeira (5 ± 2°C) ou a temperatura ambiente (25 ± 2°C) mostraram-se estáveis por 30 dias não apresentando alterações significativas em seus parâmetros físico-químicos. A atividade antiinflamatória do óleo e da formulação apresentaram significância estatística quando comparadas aos respectivos controles negativos com p<0,001 para ambos. A microemulsão apresentou-se uma forma farmacêutica eficaz para essa atividade demonstrando grande potencial para o aumento da permeabilidade cutânea do óleo de sucupira confirmando a possibilidade da obtenção de um fitoterápico de uso tópico com ação antiinflamatória.
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Gomes, José [Verfasser]. "Synthesis of Majucin-Type Sesquiterpenes and Immobilization and Visualization of Quorum Sensing Signaling Molecules / José Gomes." München : Verlag Dr. Hut, 2014. http://d-nb.info/1053859953/34.
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施麗琼 and Lai-king Sy. "Structure elucidation and oxidation chemistry of natural products." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1998. http://hub.hku.hk/bib/B3123768X.
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Porter, Joshua D. "A Chemical Investigation of Australian Winteraceae." Thesis, Griffith University, 2022. http://hdl.handle.net/10072/419713.
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The Winteraceae are a small primitive family of angiosperms endemic to the cool rainforests and montane subtropics of South America, Melanesia, Australasia, and South-East Asia below the Wallace line.The medicinal value of Winteraceae plants branches from extensive use in traditional medicine regimens to use in modern clinical applications. Nonvolatile drimane sesquiterpenes do not occur broadly in nature. However, they are reported to be a chemotaxonomic characteristic of the Winteraceae. Many of those identified from the Winteraceae comprise structural features that are either unique to the family or
identified from a minimal number of natural sources.3 Biological investigations on the drimane structure class have identified several activities attractive for drug discovery and may be linked to their usefulness in traditional medicines.
Bubbia and Tasmannia are the only Winteraceae genera with species endemic to Australia. Except for Tasmannia lanceolata and studies on the essential oil content of both genera, the chemistry of the Australian Winteraceae is poorly studied and remains an unexploited source of potentially new biologically active natural products.The primary aim of this thesis was to investigate the chemistry of unexplored Australian Winteraceae species to identify new drimane sesquiterpene natural products and improve
the current knowledge of the chemistry of Australian Winteraceae. This was achieved by exploring the chemistry of two Australian Winteraceae species.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
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Simpson, Melissa Diane. "An Evaluation of Hibiscus moscheutos ssp. lasiocarpos and Ipomoea pandurata as host plants of the specialist bee, Ptilothrix bombiformis (Apoidea: Emphorini) and the role of floral scent chemistry in host-selection." OpenSIUC, 2009. https://opensiuc.lib.siu.edu/theses/107.
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Ptilothrix bombiformis (Hymenoptera: Apoidea) is a specialist bee belonging to the tribe Emphorini. The emphorine phylogeny suggests that Convolvulacea is the ancestral plant family and independent evolutionary host-switches to several unrelated plant families have occurred. The role of floral scent has been well-characterized in pollination systems involving moths, butterflies, bumblebees, and honeybees, but little is known about how specialist bees mediate host selection, or how host-choice evolved in specialist bees. This research investigates the role of floral scent in host selection by P. bombiformis. Ptilothrix bombiformis has traditionally been classified as a Hibiscus (Malvaceae) oligolege. My research shows that it can now be placed into a more detailed dietary classification as an eclectic oligolege because it also collects pure pollen loads from a distantly-related plant, Ipomoea pandurata (Convolvulaceae). Using dynamic headspace sampling and gas chromatography-mass spectrometry, I obtained floral chemical profiles for Hibiscus moscheutos ssp. lasiocarpos and Ipomoea pandurata. Both flowers contain aliphatics, aromatic compounds, monoterpenes, and sesquiterpenes. The host flowers have 14 shared compounds in their floral scent, which may be responsible for the bees' ability to recognize and utilize I. pandurata, a member or the emphorine ancestral host-plant family. Some of these shared compounds are also found in other emphorine host plants and may be responsible for their constraint in host-use.
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Schmiedel, Volker Martin [Verfasser]. "Strained Terpenes as Targets - Total Synthesis of the Dichrocephone Sesquiterpenes and Studies towards Xenicane Diterpenes / Volker Martin Schmiedel." Berlin : Freie Universität Berlin, 2018. http://d-nb.info/1160235716/34.
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Rio, Ricardo Gomide Woisky Do. "Atividade antiinflamatória, toxicidade e fitoquímica do óleo-resina de copaíba, proveniente de diferentes espécies, e de suas respectivas frações (OU) Atividade antiinflamatória, toxicidade e aspectos químicos do óleo-resina de Copaíba, proveniente de diferentes espécies, e de suas frações." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/9/9138/tde-23092011-164642/.
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Espécies do gênero Copaifera (Leguminosae) são nativas de regiões tropicais da América Latina e África. No Brasil, seu óleo-resina é amplamente utilizado em medicina popular como antiinflamatório, antisséptico e cicatrizante. No presente trabalho, avaliou-se, em uma primeira fase, a atividade antiinflamatória em modelo experimental agudo das seguintes amostras de óleo-resina: comercial, gentilmente cedida pela empresa Pronatus, Copaifera reticulata, C. multijuga e C. paupera. As amostras foram administradas pela via oral, sendo selecionada, das amostras identificadas botanicamente, a C. reticulata por apresentarem maior atividade. A amostra comercial também foi ensaiada no modelo experimental acima. Os óleo-resinas foram analisados por cromatografia gasosa acoplada à espectrometria de massas tendo revelado a presença de sesquiterpenos e diterpenos. Foram identificados vinte e dois compostos na amostra comercial e vinte seis na amostra de C. reticulata. Deste total, seis substâncias foram comuns a ambas as amostras. A seguir, os óleos-resinas foram destilados e separadas suas respectivas frações sesqui e diterpênicas. Tanto os óleos-resinas quanto suas frações foram avaliados farmacologicamente. As atividades farmacológicas testadas foram: atividade antiinflamatória aguda, subcrônica, crônica e ensaios de toxicidade aguda, subcrônica e citotoxicidade. A atividade antiinflamatória foi testada em cinco modelos: edema de pata induzido pela carragenina, nistatina e miconazol; indução de formação de tecido granulomatoso e dermatite induzida pelo óleo de cróton. Nos modelos utilizados as doses testadas foram de 2,47 ml/kg (DE50 no modelo da carragenina) para a amostra comercial e suas frações sesqui e diterpênicas e 2,02 ml/kg (Dose equipotente no modelo da carragenina) para a amostra de C. reticulata e suas frações sesqui e diterpênicas). Em todos os ensaios realizados com as amostras, evidenciaram-se intensa atividade antiflogística, com exceção da C. reticulata que apresentou elevada toxicidade no modelo de indução do tecido granulomatoso. Nos ensaios de toxicidade aguda, a amostra C. reticulata (DL50 = 4,48 ml/kg) apresentou toxicidade maior que a amostra comercial (DL50 > 12,35 ml/kg). Suas frações sesquiterpênicas foram bem menos tóxicas que seus correspondentes óleos-resinas com DL50 maiores que 9,14 e 20 ml/kg, respectivamente para C. reticulata e amostra comercial: Por outro lado, a fração resinosa (diterpênica) apresentou alta toxicidade com DL50 superiores a 2,85 e 1,29 ml/kg, respectivamente para a amostra comercial e C. reticulata. Nos ensaios de toxicidade subcrônica confirmou-se a toxicidade menor para a fração sesquiterpênica da amostra de C. reticulata. O óleo-resina de C. reticulata apresentou toxicidade renal e alterações hepáticas indicando que pode haver um comprometimento hepático.Species of the genus Copaifera (Leguminosae) are native of tropical regions in Latin America and Africa. In Brazil, its oil-resin is widely utilized in popular medicine as anti-inflammatory, antiseptic and cicatrizing medicine. In the present work, we initially evaluated the acute anti-inflammatory activity of the following samples: commercial, Copaifera reticulata, C. multijuga and C. paupera. All the samples were administered by oral route. This initial pharmacological evaluation revealed that the C. reticulata was clearly more effective. In the second part of this work, the C. reticulata and the commercial samples, kindly provided by Pronatus-Manaus, were investigated. The oil-resins of the selected samples were analyzed by gas chromatography connected with mass spectrometry, revealing the presence of sesquiterpens and diterpens. Twenty two compounds in the commercial sample and twenty six in the C. reticulata were identified. Then after, the oil-resins were distilled and separated in their respective sesqui and diterpens fractions. Both oil-resins and their fractions were pharmacologically evaluated. The pharmacological evaluations were: acute, sub-chronic and chronic anti-inflammatory activities and acute, sub-chronic toxicities and cito-toxicities assays. The anti-inflammatory activity was studied in five experimental models: carrageenan, nistatin and miconazole paw oedema; induction of granulomatous tissue formation and croton oil dermatitis. The administered doses by oral route were 2.47 ml/kg (EQ50 for carrageenan model) to commercial sample and its sesqui and diterpens fractions, and 2.02 ml/kg to C. reticulata sample and its sesqui and diterpens fractions. All the assays carried out with the selected samples showed intense anti-flogistic activity, except for C. reticulata that exhibited high toxicity in the granulomatous tissue model. In the acute toxicity studies, C. reticulata (LD50 = 4.48 ml/kg) revealed greater toxicity in comparison with the commercial sample (LD50 > 12.35 ml/kg). Its sesquiterpens fractions were less toxic that its correspondent oil-resins with LD50 higher than 9.14 and 20 m1/kg, for C. reticulata and commercial sample, respectively. On the other hand, resin fraction (diterpenic) presented high toxicity with LD50 higher than 2.85 and 1.29 ml/kg for commercial and C. reticulata samples, respectively. The sub-chronic assays, confirmed the less toxicity for the C. reticulta sesquiterpenic fraction. The C. reticulata oil-resin presented renal toxicity and hepatics alterations.
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Alfaro, Inocente Edna Ariel. "Insecticidal and antifeedant activities of Malagasy medicinal plant (Cinnamosma sp.) extracts and drimane-type sesquiterpenes against Aedes aegypti mosquitoes." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1586449408494604.
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Toledo, Adrieli Gorlin. "Composição química e atividades biológicas das folhas de Eugenia involucrata DC." Universidade Estadual do Oeste do Paraná, 2018. http://tede.unioeste.br/handle/tede/3882.
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Scientific researches with Brazilian native species have aroused a growing interest in the search for active compounds with biological potential. The fruit species Eugenia involucrata DC. (Myrtaceae), known as “cerejeira-do-mato”, is popularly used in the form of tea with antidiarrheal and digestive action. In the literature, although researches with the fruit because to its commercial value, studies with the leaves of the species are scarce, being few data related to the biological activities of this plant. Therefore, the objective of this work was to identify the chemical components of the essential oil by gas chromatography coupled to mass spectrometry (GC-MS) and to perform the phytochemical exploration of the plant extracts through colorimetric visualization and / or precipitate formation. In addition, the antimicrobial activity by the broth microdilution technique and the antioxidant activity by the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) method were evaluated. In the analysis of the essential oil by GC-MS 28 compounds were identified, all sesquiterpenes, corresponding to 89.41% of the essential oil. The antimicrobial activity of the oil was observed for all Gram-positive bacteria tested and for yeast C. albicans. The essential oil presented a reduction capacity of DPPH up to 66.81%, evidencing its antioxidant potential. The phytochemical prospection of the extracts detected the presence of saponins, steroids, flavonoids and tannins. The antimicrobial and antioxidant activities were observed in all extracts tested. The extracts that presented the best results were: methanolic with antimicrobial activity between 3.12 and 25 mg.mL-1 and antioxidant percentage of 95.85% in the concentration of 1.0 mg.mL-1; and the ethanolic with antimicrobial activity between 3.12 and 50 mg.mL-1 and antioxidant activity of 92.84% in the concentration of 1.0 mg.mL-1. It is suggested that the biological activities found for the essential oil are related to its major compounds: elixene (26.53%), β-caryophyllene (13.16%), α-copaene (8.41%) and germacrene D (7.17%). Regarding the extracts, due to the proven presence of flavonoids and tannins, it is suggested that these phenolic compounds are related to the activities found.
As pesquisas científicas com espécies nativas brasileiras têm despertado um crescente interesse na busca por compostos ativos com potencial biológico. A espécie frutífera Eugenia involucrata DC. (Myrtaceae), conhecida por cerejeira-do-mato, é popularmente usada na forma de chá com ação antidiarreica e digestiva. Na literatura, apesar de pesquisas com o fruto devido ao seu valor comercial, estudos com as folhas da espécie são escassos, sendo encontrados poucos dados relacionados as atividades biológicas dessa planta. Diante disso, este trabalho objetivou identificar os componentes químicos do óleo essencial por cromatografia gasosa acoplada à espectrometria de massas (CG-EM) e realizar a prospecção fitoquímica dos extratos vegetais por meio da visualização colorimétrica e/ou na formação de precipitado. Além disso, foi avaliada a atividade antimicrobiana pela técnica de microdiluição em caldo e a atividade antioxidante pelo método do 2,2-difenil-1-picril-hidrazila (DPPH). Na análise do óleo essencial por CG-EM identificou-se 28 compostos, todos sesquiterpenos, correspondendo a 89,41% do óleo essencial. A atividade antimicrobiana do óleo foi observada para todas as bactérias Gram-positivas testadas e para a levedura C. albicans. O óleo essencial apresentou capacidade redutora de radicais DPPH de até 66,81%, evidenciando seu potencial antioxidante. A prospecção fitoquímica dos extratos detectou a presença de saponinas, esteroides, flavonoides e taninos. As atividades antimicrobiana e antioxidante foram observadas em todos os extratos testados. Os extratos que apresentaram os melhores resultados foram: metanólico com atividade antimicrobiana entre 3,12 e 25 mg.mL-1 e percentual antioxidante de 95,85% na concentração de 1,0 mg.mL-1; e o etanólico com atividade antimicrobiana entre 3,12 e 50 mg.mL-1 e atividade antioxidante de 92,84% na concentração de 1,0 mg.mL-1. Sugere-se que as atividades biológicas encontradas para o óleo essencial estejam relacionadas aos seus compostos majoritários: elixeno (26,53%), β-cariofileno (13,16%), α-copaeno (8,41%) e germacreno D (7,17%). Referente aos extratos, devido a comprovada presença de flavonoides e taninos, sugere-se que estes compostos fenólicos estejam relacionados as atividades encontradas.
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Beatriz, Adilson. "Estudos sobre a síntese de heliangolidos pela reação de Diels-Alder." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/59/59138/tde-25102001-125134/.
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O objetivo deste trabalho foi desenvolver métodos para sintetizar o esqueleto carbônico básico de furanoeliangolidos. Goiazensolido é um típico exemplo destes produtos naturais, cujo núcleo estrutural podemos considerar como sendo de um biciclo[6.2.1]undecano. Imaginamos que este tipo de estrutura poderia ser preparado através da reação de Diels-Alder seguida da ruptura de uma ligação interna de um sistema policíclico. Na nossa primeira tentativa, fomos capazes de preparar o dimesilato 75, mas a clivagem da ligação C2-C7 não pôde ser efetivada, nem sob condições solvolíticas, nem por tratamento com base, somente misturas complexas foram obtidas em todas as tentativas. Nossa próxima abordagem foi baseada no possível rearranjo térmico de um sistema contendo dois anéis de ciclobutanos fundidos entre si (um sistema tetraciclo[6.2.1.02,7.03,6]undecano). Entretanto, embora tenhamos conseguido preparar os compostos 87 e 101 com bons rendimentos, o produto de fotocicloadição [2 + 2] não pôde ser obtido. Finalmente, em nossa terceira abordagem, baseada em uma reação de retro-aldol, conseguimos obter o sistema biciclo[6.2.1]undecano 117, pelo tratamento de 116 com NaH em tolueno aquecido até refluxo. O composto foi preparado por dois caminhos diferentes, ambos envolvendo reações de Diels-Alder.The aim of this work was to develop methods to synthesize the main carbon skeleton of the furanoheliangolides. Goyazensolide is a typical example of these natural products, whose core structure is a bicyclo[6.2.1]undecane. We envisioned that this framework could be prepared through the Diels-Alder reaction followed by a cleavage of an internal bond of the polycyclic ring system. In our first attempt, we were able to prepare the dimesilate 75, but the desired cleavage of the C2-C7 bond could not be effected, neither under solvolytic conditions, nor by base treatment, complex mixtures being the result in all attempts. Our next approach was based in the possible thermal rearrangement of the system consisting of two fused cyclobutane rings (a tetracyclo[6.2.1.02,7.03,6]undecane ring system). However, although compounds 87 and 101 could be prepared in good yields, no photochemical [2 + 2] cycloaddition product could be obtained from them. Finally, in our third approach, based in a retro aldol reaction, we succeeded in preparing the desired bicyclo[6.2.1]undecane system 117 by treatment of 116 with NaH in refluxing toluene. Compound 116 was prepared by two different ways, both involving Diels-Alder reactions.
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Viegas, Junior Claudio. "Estratégias sintéticas para a preparação enantiosseletiva do (+)-pendulol." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 1998. http://hdl.handle.net/10183/24992.
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Duas abordagens foram estudadas para a síntese enantiosseletiva do (+)-4a-H-eudesman-5a-ol ou (+)-pendulol (128) (esquema 1) . Numa primeira rota sintética (Rota 1), construiu-se enantiosseletivamente a octalona 92 , por urna reação de anelação de Robinson assimétrica via imina quiral. A redução da octalona 92, produziu o f3-álcool 114, que por desoxigenação do carbono C-3, forneceu a octalina 120. Contando com a possibilidade da metila angular induzir estereosseletividade na epoxidação da ligação dupla endocíc1ica na octalina 120, tentou-se a obtenção do a-epóxido 124. Entretanto, este foi obtido em urna mistura equimolecular com seu diastereoisômero, o f3-epóxido 124a. Numa segunda alternativa sintética (Rota 2), foi estudada a redução da octalona 92 L-selectride® de modo a obter-se o a-álcool 115. A complexação da a-hidroxila do substrato com o agente epoxidante, com posterior desoxigenação do carbono C-3, poderia permitir a preparação estereosseletiva do epóxido 124. O resultado desta etapa de redução não forneceu o produto esperado em rendimento apreciável, o que conduziu à utilização da metodologia de inversão da configuração da hidroxila em 114, desenvolvida por Mitsunobu. O a-álcool 115 foi obtido e epoxidado fornecendo o epoxi-álcool135. As tentativas de desoxigenação do carbono C-3via xantato não forneceram o a-epóxido 124. Desta forma optou-se pela abertura do anel oxirano em 135, sendo obtido o dio1137. Este foi submetido à mesilaçãoda hidroxila em C-3 com posterior redução por LiAIH4, o que forneceu urna mistura de prováveis produtos de eliminação, não permitindo a obtenção do (+)-pendulol (128). esquema 1: rotas sintéticas para a sintese enatiosseletiva do (+)-pendulol.Two approaches were studied to the enantioselective synthesis of (+)-4a-H-eudesman-Sa-ol or (+)-pendulol (128) (scheme 1). On a first synthetic route (route 1), the octalone 92 was prepared by a Robinson annulation reaction via chiral imine. The reduction of compound 92 and deoxigenation on the C-3 carbon of the correspondent p-alcohol 114, led to the octalin 120. We expect that the angular methyl grou p could exerce sterical hindrance on the p-face of the biciclic sistem and thus directec de epoxidation to the opposite side to afford the epoxide 124 estereosselectively. However, the desired epoxide 124 was obtained in an equimolecular mixture with the diastereoisomer 124a. On a second alternative synthetic route (route 2), was studied reduction of octalone 92 L-selectride® to afford the a-alcohol 115. The expected complexation of the a-hidroxyl group to the epoxidizing agent could permit the stereoselective preparation of epoxide 124. the result of this step doens't led to the expected product in good yield. 80 one alternative was the invertion of the hidroxyl configuration on carbon C-3 in compound 114, via Mitsunobu methodology. The a-alcohol 115 was obtained and epoxidized to afford the epoxi-alcohol 135. All affords to deoxigenate the C-3 carbon via xantate do not permit the preparation of the epoxide 124. 80, the oppenning of the oxirane ring in compound 135 was done first, ledding to the diol 137. This compound was submitted to mesylation folowed by reduction, ledding to a mixture of probable elimination products, but de (+)-pendulol (128) was not detected. scheme 1: synthetic routes to the enantioselective synthesis of (+)-pendulol.
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Manwill, Preston Kim. "Discovery and Development of Natural Products from Plant and Microbial Sources: Drimane Sesquiterpenes and Abyssomicins as Mosquito Control and Antimicrobial Agents." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1591285556969447.
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Andersson, Marie. "Elucidation of the product synthesis of the sesquiterpene synthase Cop6 isolated from Coprinus cinereus." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-17252.
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Mushrooms are believed to have a great potential for production of bioactive metabolites e. g. terpenes, a group of interesting compounds with diverse chemical properties such as antitumour and antibacterial activity. Cop6 is a terpene cyclase isolated from the mushroom Coprinus cinereus that catalyzes the cyclization of farnesyl diphosphate (FPP) to mainly α-cuprenene. In this study gas chromatography combined with mass spectroscopy (GC-MS) is used to analyze the product profile of Cop6 mutants created by PCR based site directed mutagenesis. The goal is to produce trichodiene, the parent hydrocarbon in the biosynthesis of trichothecene antibiotics and mycotoxins. Valine instead of tyrosine in amino acid position 195 resulted in cyclisation of (E)-β-Farnesene and (3Z,6E)-α-Farnesene besides the products of the wild type enzyme. Another mutant with aspartic acid instead of asparagine in position 224 resulted in the synthesis of β-Bisabolene except for α-cuprenene and methionine in position 74 instead of isoleucine killed the activity of the cyclase. Furthermore, an attempt to saturation of position 98 was made, resulting in four mutants. Two of them essentially killed the activity of the cyclase whereas two had minor effect of the product profile compared to the wild type.
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Sun, Pulu. "Molecular and biochemical studies of fragrance biosynthesis in rose." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSES005/document.
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La rose est l'une des plantes ornementales les plus populaires, dont les composés volatils sont non seulement impliqués dans les interactions des fleurs avec l’environnement au sens large, mais aussi largement utilisés dans l’industrie des arômes et parfums. Le chapitre 1 décrit l'histoire de la culture de la rose, les usages de son parfum, les connaissances actuelles sur la biosynthèse des composés de ce parfum, ainsi que les voies de biosynthèse des composés volatils qui ont été récemment élucidées chez différentes plantes. Les chapitres expérimentaux 2 et 3 analysent les fonctions de deux gènes exprimés dans les pétales de rose. Ils codent pour des protéines Nudix hydrolase 1 (NUDX1). Le gène NUDX1-1 (nommé RhNUDX1 dans la publication) a été découvert en comparant les transcriptomes de deux cultivars de rose, Rosa x hybrida cv. 'Papa Meilland' (PM) très parfumé et R. x hybrida cv. 'Rouge Meilland' (RM), dépourvu de parfum. Le gène RhNUDX1-1 n'est exprimé que chez PM et son expression est corrélée avec la production de monoterpènes dans les pétales, en particulier de géraniol. Lors de l'étude d'une descendance issue du croisement de R. chinensis cv. ‘Old Blush’ (OB) et de R. x wichurana (Rw), le gène orthologue RcNUDX1-1a, présentant la même fonction, a été caractérisé chez OB. Un gène paralogue, RwNUDX1-2, a été découvert chez Rw et il a été démontré que son expression présentait une corrélation avec la production sesquiterpènes, en particulier de E,E-farnesol. Une série d'analyses in vitro et in vivo ainsi qu'une analyse de corrélation ont permis de vérifier la fonction de RhNUDX1-1, qui hydrolyse le géranyl diphosphate (GPP) en géranyl monophosphate (GP). Une phosphatase non identifiée pourrait catalyser la transformation du GP en géraniol. Des expériences de fusion avec la Green Fluorescent Protein (GFP), suivies de transformation transitoire de feuilles de tabac, ont révélé que RhNUDX1-1 était localisée dans le cytoplasme. Les mêmes approches (analyses QTL, essais enzymatiques et expression transitoire) ont également été appliquées à RwNUDX1-2, démontrant sa fonction dans la production de E,E-farnesol. La cartographie de RwNUDX1-2 et la localisation subcellulaire de la protéine sont encore à l'étude. De plus, la cristallographie des protéines et la modélisation ont été employées pour étudier le mécanisme de l'interaction NUDX1-substrat et les acides aminés potentiellement importants pour la reconnaissance du substrat. Collectivement, ces données révèlent une voie alternative pour la biosynthèse des terpènes, en particulier le géraniol et E,E-farnesol, via l'hydrolyse des prényl diphosphates par les enzymes NUDX1. Nos résultats montrent que la production de composés volatils dans les pétales est fortement corrélée avec l’expression des gènes des voies de biosynthèse. Par conséquent, la régulation transcriptionnelle de RcNUDX1-1a et RwNUDX1-2 joue probablement un rôle important dans la production de parfum. Les promoteurs de RcNUDX1-1a, RcNUDX1-1b, et RwNUDX1-2 et deux facteurs de transcription (FT), RcbHLH79 (OB TF) et RwbHLH79 (Rw TF) ont ainsi été isolés et testés (Chapitre 4). Les FT candidats ont été choisis lors d’une analyse RNA-Seq (Chapitre 5). En utilisant des tests d'expression transitoire avec le gène rapporteur GUS (β-glucuronidase) dans les pétales de rose, il a été montré que les trois promoteurs pouvaient entraîner l'expression de GUS. Les deux FT ont ensuite été introduits dans des feuilles de tabac avec les promoteurs testés, pour voir s'ils étaient capables d'activer ces promoteurs. Aucune transactivation significative n'a été détectée, même si Rw TF semblait pouvoir activer une construction témoin (promoteur du gène de la tomate TPS5. Les transcriptomes de quatre cultivars de rose, dont deux produisent du géraniol mais pas de E,E-farnesol et deux autres produisent du E,E-farnesol mais pas de géraniol, ont été analysés (Chapitre 5) et ont abouti à une liste de FT putatifs pour une étude plus approfondieRoses are one of the most popular ornamental plants, whose volatiles are not only involved in environmental interactions but also widely used for industries. Chapter 1 describes the cultivation history of roses, usages of rose fragrance, knowledge on the biosynthesis of rose scent compounds, as well as non-canonical biosynthesis pathways of other plant volatiles. Experimental chapters (Chapter 2 and 3) analyse the functions of two genes expressed in rose petals, both encoding Nudix hydrolase 1 (NUDX1) protein. NUDX1-1 gene (named RhNUDX1) was first discovered by comparing the transcriptomes of two rose cultivars, the scented Rosa x hybrida cv. ‘Papa Meilland’ (PM) and the unscented R. x hybrida cv. ‘Rouge Meilland’ (RM). RhNUDX1-1 was only expressed in scented PM and its expression exhibited a positive correlation with the monoterpenoid production in petals, especially geraniol. When studying a rose progeny of R. chinensis cv. ‘Old Blush’ (OB) and R. x wichurana (Rw), an orthologous gene RcNUDX1-1a was found in OB, whose expression also had positive correlation with geraniol emission. A paralogous gene in Rw, RwNUDX1-2, was discovered and it was shown that its expression displayed a correlation with the sesquiterpenoid production, especially E,E-farnesol. A series of in vitro and in vivo assays as well as correlation analyses verified the function of RhNUDX1-1, which hydrolysed geranyl diphosphate (GPP) to geranyl monophosphate (GP). The transformation of GP into geraniol is supposed to be processed by an, as yet, unidentified phosphatase. The prediction of the localisation together with green fluorescent protein (GFP) fusion experiments revealed that RhNUDX1-1 was located in the cytosol. A series of approaches (QTL analyses, enzymatic assays and transient expression studies) were also applied to RwNUDX1-2, demonstrating its function in the production of E,E-farnesol. Mapping of RwNUDX1-2 and subcellular localization of the protein are still under investigation. Furthermore, protein crystallography and protein modelling illustrated the NUDX1-substrate interaction and proposed several residues that may be important for substrate recognition, although further experimental and computational data are required to gain more insight into the enzymatic mechanism. Collectively, these data revealed an alternative pathway for the biosynthesis of terpenoids, especially geraniol and E,E-farnesol, in rose, via the hydrolysis of prenyl diphosphates by NUDX1 enzymes. Transcriptional regulation of RcNUDX1-1a or RwNUDX1-2 probably plays an important role in the scent production by rose petals. Therefore, three promoters, pOB1a (promoter of RcNUDX1-1a), pOB1b (promoter of RcNUDX1-1b, not expressed in rose petals), pRw (promoter of RwNUDX1-2) were cloned and tested (Chapter 4). In addition, two transcription factors (TFs), RcbHLH79 (OB TF) and RwbHLH79 (Rw TF) candidates were chosen via RNA-Seq analysis as their expression correlated with expression of RcNUDX1-1a or RwNUDX1-2, respectively (Chapter 5). Using transient expression assays with a reporter gene, β-glucuronidase (GUS) in rose petals, it was shown that all three promoters could drive the expression of GUS, suggesting that all of them are active. However, quantification of promoter activities is still needed. OB TF and Rw TF were introduced into Nicotiana benthamiana leaves together with the promoters driving GUS , to determine if they were able to activate these promoters. However, no significant transactivation was detected in any promoter-TF combination. The expression of the TF in the progeny was also analysed but, due to the similarity of the sequences of family members, no conclusive data were obtained. Transcriptomes of the petals four roses, two of which produce geraniol but not E,E-farnesol and two that produce E,E-farnesol but not geraniol, were analysed (Chapter 5) and this resulted in a list of putative scent related genes and transcription factors for further study
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Anese, Simoni. "Fracionamento de extratos bioativos de Drimys brasiliensis Miers e identificação de compostos com atividade fitotóxica e inseticida." Universidade Federal de São Carlos, 2014. https://repositorio.ufscar.br/handle/ufscar/1811.
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Previous issue date: 2014-02-21Along its evolutionary history, plants have developed biosynthetic routes to synthesize and accumulate a wide variety of secondary metabolites, which respond to the environment characteristics where they occur. The studies about these compounds effects on nearby organisms constitute the field of allelopathy. Allelopathy is an important phenomenon in plant chemical ecology that involves bioactive compounds, from which one can produce natural pesticides that would be more specific, less harmful to the environment and applied to a model of sustainable agriculture. Drimys brasiliensis Miers is found in the Atlantic Forest and in the Cerrado domain. It s chemically characterized by the presence of monoterpenes, sesquiterpenes and flavonoids, with great use potential in the pharmaceutical industry. There are few studies about the allelopathic potential of D.brasiliensis and its secondary metabolites to act as natural pesticides, specialy as herbicide or insecticide. Thus, in the first chapter we studied the phytotoxic potential of aqueous extracts of D.brasiliensis according to the seasonality and different plant organs. The phytotoxic effect of D.brasiliensis isinfluenced by the period of collection, with more evident activity in leaves collected in the dry season. Aqueous extracts from leaves, roots and stems of D.brasiliensis showed activity on crop plants, and all organs are a promising source in the search of phytotoxic compounds. In the second chapter, we investigated the phytotoxic potential of crude extract fractions from D. brasiliensis roots and leaves on weeds. The inhibitory effects of the root hexane fraction on seedling growth was similar to the herbicide, indicating that D. brasiliensis is a possible alternative form of control for the weed species examined. In chapter three, was carried a bioassay-guided isolation of bioactive compounds present in D.brasiliensis roots. Four drimanes sesquiterpenes were isolated from bioactive fractions of roots, determined as polygodial, polygodial 12 α- acetal, dendocarbin L and (+) fuegin. The polygodial caused phytotoxic effects on wheat coleoptile and on crop and weed species. In the last chapter, the effect of the hexane fraction and polygodial obtained from D.brasiliensis roots was evaluated on Toxoptera citricidus Kirkaldy (black citrus aphid), and both caused toxicity, with high mortality on nymphs and adults stages of this aphid. The polygodial, isolated for the first time in the roots of D. brasiliensis, may be the primarily responsible for the biological activities detected in this study. The herein presented data allow the indication of this compound as a potential biopesticide.
Ao longo do seu processo evolutivo, as plantas desenvolveram rotas de biossíntese, através das quais sintetizam e acumulam uma ampla variedade de metabólitos secundários, que respondem às características do meio onde se encontram. Os estudos realizados sobre os efeitos desses compostos em organismos próximos constituem o campo da alelopatia. A alelopatia representa um importante fenômeno dentro da ecologia química de plantas e envolve a síntese de metabólitos secundários, a partir dos quais se pode produzir pesticidas naturais, mais específicos, menos prejudiciais ao ambiente e aplicáveis a um modelo de agricultura de base ecológica. A espécie Drimys brasiliensis Miers ocorre na Mata Atlântica e no domínio do bioma Cerrado. Fitoquimicamente é caracterizada pela presença de monoterpenos, sesquiterpenos e flavonóides com grande potencial de uso na indústria farmacológica. São poucos os trabalhos publicados que tratam de investigações do potencial de D. brasiliensis e de seus metabólitos secundários para atuarem como pesticidas naturais, principalmente no que concerne às ações herbicida e inseticida. Nesse sentido, no primeiro capítulo foram realizadas investigações sobre o potencial fitotóxico de extratos aquosos de D. brasiliensis em função da sazonalidade e de diferentes órgãos da planta. O efeito fitotóxico de D. brasiliensis foi influenciado pela época de coleta, com atividade mais evidente em folhas coletadas na estação seca. Extratos aquosos de folhas, raízes e cascas do caule de D. brasiliensis apresentaram atividade inibitória sobre plantas cultivadas, e todos os órgãos constituem uma fonte promissora para a busca de compostos fitotóxicos. No segundo capítulo, foi investigado o potencial fitotóxico de frações do extrato bruto de folhas e raízes de D. brasiliensis sobre as plantas infestantes Panicum maximum Jacq e Euphorbia heterophylla L. As inibições no crescimento inicial, decorrentes da aplicação da fração hexânica das raízes, foram similares ao efeito produzido pelo herbicida oxyfluorfen, indicando a eficiência de D. brasiliensis para o controle das espécies infestantes estudadas. No terceiro capítulo, foi realizado o isolamento biomonitorado de compostos presentes em raízes de D. brasiliensis. Foram isolados quatro drimanos sesquiterpenos das frações bioativas de raízes, determinados como poligodial, poligodial 12 α-acetal, dendocarbin L e (+) fuegin. O poligodial exerceu efeitos fitotóxicos sobre coleóptilos de trigo e sobre duas espécies infestantes e uma cultivada avaliadas. No último capítulo, o efeito da fração hexânica e do poligodial obtidos de raízes de D. brasiliensis foi avaliado sobre Toxoptera citricidus Kirkaldy (pulgão-preto dos citros), e ambos causaram toxicidade, provocando elevada mortalidade nas fases de ninfas e adultos deste afídeo. O poligodial, isolado pela primeira vez nas raízes de D. brasiliensis, pode ser o principal responsável pelas atividades biológicas registradas neste estudo. Os resultados obtidos permitem a indicação deste composto como um potencial biopesticida.
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Rocha, Bruno Alves. "Transformações microbianas da lactona sesquiterpênica tagitinina C." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/60/60138/tde-30072009-160522/.
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A busca por moléculas de origem natural que ocupem um espaço químico diferente daquelas já existentes tornou-se uma necessidade para atender às novas demandas das indústrias farmacêuticas. A pesquisa envolvendo transformações microbianas de metabólitos secundários de origem vegetal pode ser utilizada como uma nova ferramenta na biosíntese destas novas substâncias, favorecendo a criação de bibliotecas ricas em estruturas com o emprego em diversos alvos biológicos. A tagitinina C é uma lactona sesquiterpênica isolada da Tithonia diversifolia (Asteraceae). Essa substância possui diversas atividades biológicas descritas na literatura. Contudo, há certa ressalva no uso de lactonas sesquiterpênicas para fins terapêuticos devido à elevada toxicidade apresentada por essas substâncias. A biotransformação de substâncias naturais de elevado interesse farmacológico pode ser utilizada com o intuito de diminuir seus efeitos tóxicos ou ampliar sua capacidade terapêutica. Assim, esse trabalho teve como objetivo a utilização de fungos para a biotranformação da tagitinina C. Os resultados obtidos mostraram que os fungos de solo Aspergillus terreus e Mucor rouxii possuem a capacidade de biotransformar tagitinina C. O fungo Aspergillus terreus levou a formação de um produto biotransformado através de uma reação não usual de epoxidação entres os C4-C5 e ainda metoxilação do C1, formando então 1-metóxi-3-hidróxi-3,10-4,5-diepóxi-8-isobutiroilóxi-germacra-11(13)-en-6,12-olido. Os resultados obtidos nesse trabalho demostram que é possível a utilização de fungos na biotransformação da tagitinina C, levando a alterações na molécula que podem influenciar no seu potencial tóxico ou terapêutico.The search for molecules of natural origin that place a chemical space which is different from the already existing has become that a need in process of discovery new chemical entities with pharmacological interest that support the demand of the pharmaceutical industries. Research involving microbial transformations the secondary metabolites from plants can be used as an alternative for the biosynthesis of such new compounds, thus facilitating the creation of libraries which are rich in structures to be screened against diverse biological targets. Tagitin C is a sesquiterpene lactone isolated from Tithonia diversifolia (Asteraceae) that displays several biological activities already described in the literature. Howeever, due to several reports describing toxic effects of sesquiterpenes lactones, there is a concern in its oral use. Thus, the biotransformation of pharmacologically interesting substances can be carried out with the aim to decrease their toxic effects or amplify their therapeutic properties. Therefore, this work aimed at using of fungi to perform biotransformations of tagitin C. The results showed that the soil fungi Aspergillus terreus and Mucor rouxii have the ability to carry out biological transformations of tagitinin C. The fungus A. terreus led to the formation of a different product through an unusual reaction of epoxidation between C4-C5 and metoxilation of C1 of tagitinin C, the derivative 1-methoxy-3-hydroxy-3,10-4,5-diepoxy-8-isobutiroyloxygermacr- 11 (13)-en-6 ,12-olide. The results of this work show that it is possible to use soil fungi in the biotransformation of tagitinin C, leading to changes in the chemical structure that may influence its toxic or therapeutic potential.
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Fantaye, Chalie Assefa Verfasser], Jonathan [Akademischer Betreuer] [Gershenzon, Ralf [Akademischer Betreuer] Oelmüller, and Ted [Akademischer Betreuer] Turlings. "The roles of plant sesquiterpenes in defense against biotic and abiotic stresses / Chalie Assefa Fantaye. Gutachter: Jonathan Gershenzon ; Ralf Oelmüller ; Ted Turlings." Jena : Thüringer Universitäts- und Landesbibliothek Jena, 2014. http://d-nb.info/1062536177/34.
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Fantaye, Chalie Assefa [Verfasser], Jonathan [Akademischer Betreuer] Gershenzon, Ralf [Akademischer Betreuer] Oelmüller, and Ted [Akademischer Betreuer] Turlings. "The roles of plant sesquiterpenes in defense against biotic and abiotic stresses / Chalie Assefa Fantaye. Gutachter: Jonathan Gershenzon ; Ralf Oelmüller ; Ted Turlings." Jena : Thüringer Universitäts- und Landesbibliothek Jena, 2014. http://d-nb.info/1062536177/34.
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Magri, Fátima Maria Motter. "Determinação estrutural e simulação de espectros de RMN13C de sesquiterpenos lactonizados utilizando métodos computacionais." Universidade de São Paulo, 1999. http://www.teses.usp.br/teses/disponiveis/46/46135/tde-04082009-114225/.
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O presente trabalho mostra a utilização de métodos computacionais e os resultados obtidos na determinação estrutural de produtos naturais, neste caso sesquiterpenos lactonizados. Nosso grupo de pesquisa tem desenvolvido nos últimos anos o projeto denominado SISTEMAT para a determinação estrutural de produtos naturais. Este sistema é composto de programas utilizados para a construção de bancos de dados capazes de armazenar qualquer tipo de informação referente a substâncias orgânicas, e programas que permitem a recuperação e análise das informações contidas nos bancos de dados (programas aplicativos). Foi também construído um programa para a previsão de espectros de RMN 13C utilizando modelos tridimensionais para a representação das moléculas. O programa considera cada carbono e sua vizinhança química em três dimensões como uma subestrutura. Para encontrar o deslocamento químico equivalente a uma nova subestrutura, ele procura no banco de dados um carbono com uma vizinhança equivalente. O banco de dados criado para o SISTEMAT contém 1300 espectros de RMN 13C de sesquiterpenos lactonizados, enquanto que o utilizado para o programa simulador de espectros de RMN 13C possui 1600 substâncias codificadas.This work shows the use of computational methods and the results obtained in the structure determination of sesquiterpene lactones. Our research group have developed in the last years the expert system named SISTEMAT, to structure determination of natural products. This system have programs used to construct a database able to store any kind of information about the compounds and programs used to retrieve and analyse informations obtained in the database. It was also planned a program to make predictions of 13C NMR spectra of sesquiterpene lactones. It uses a codification working with tridimensional substructures. The program treats each carbon atom and its neighbouring as a substructure. It can scan all the database for other equal or similar chemical shift values that can be used to predict the 13C NMR spectrum for a new compound. The current database contains about 1300 13C NMR spectra of sesquiterpene lactones. The other database used in the program for 13C NMR prediction has 1600 compounds.