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).

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 approfondie / Roses 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

<p>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 <em>Coprinus cinereus</em> 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. </p>

This study identified new compounds with pest control activities. The two sources of candidates that were followed here were the main heartwood extract of Alaska Yellow Cedar (AYC) constituents and several semi-synthetic counterparts. Five compounds were isolated and identified for the first time in AYC heartwood in this research: two monoterpenes, two sesquiterpenes, and one lignan. The two monoterpenes were (1S)-2-oxo-3-p-menthenol (41) and (4R)-4-hydroxy-4-isopropyl-cyclohex-1-enecarboxylic acid (63). The two sesquiterpenes were (5S,7R,10R,11R)-eudesm-4(14)-ene-11,12-diol (46) and (4R,5S,7R)-1(10)- eremohpilen-11,12-diol (59). The lignan was (1R,2S,5R,6S)-2,6-bis-(3,5- dimethoxy-4-hydroxyphenyl)-3,7-dioxabicyclo-[3.3.0]octane,(67). Structures for these compounds were confirmed on the basis of spectroscopic techniques such as 1- and 2-D NMR, high resolution MS and IR. The pest control activity studies of 15 compounds isolated or semi-synthesized from AYC heartwood were conducted at the Centers for Disease Control and Prevention (CDC). Two types of studies were conducted--short-term (24h) and residual (over 1-4 weeks) activity for application against three types of pests related to human health - nymphal I. scapularis ticks, adult X cheopis fleas and adult Ae. eagypti mosquitoes. The 24 h studies revealed that nootkatone, valencene-13-aldehyde and valencene-13-ol were the most active among the studied compounds against the three pests. They exhibited highly improved pest control activities compared to valencene. This suggests that oxidation on both positions C-2 and C-13 of the eremophilane ring structure has an important effect on the activity. For compounds where the conformation of the eremophilane bicyclic ring has been altered, the activity seemed to diminish greatly. The above mentioned three compounds can be good candidates as pest control lead compounds. The residual studies revealed that the most active compounds exhibited activity profiles that generally decreased with time. Although the long-term safety of these compounds has yet to be evaluated, the natural origin and the long history of use of these compounds suggest that they can be promising candidates. This study revealed that the three most promising compounds in the 24 h study exhibited reasonably promising behavior, which makes them even stronger as pest control candidates. / Graduation date: 2004

Among Nature’s creation, terpenoids are more versatile and exciting natural products. In a remarkable display of synthetic ingenuity and creativity, nature has endowed terpenes with a bewildering array of carbocyclic frameworks with unusual assemblage of rings and functionalities. This phenomenal structural diversity of terpenes make them ideal targets for developing and testing new synthetic strategies for efficient articulation of carbocyclic frameworks. The thesis entitled “Total synthesis of sesquiterpenes acorenols, chamigrenes, and laurokamurene B; and Enantiospecific synthesis of ABC-ring system of A-nor and abeo pentacyclic triterpenes” describes the studies directed towards the total synthesis of the sesquiterpenes mentioned in the title and exploratory studies towards triterpenoids. In each chapter of the thesis, the compounds are sequentially numbered (bold) and references are marked sequentially as superscripts and listed at the end of the chapter. All the spectra included in the thesis were obtained by xeroxing the original NMR spectra. The sesquiterpenes acorenols, containing an interesting spiro[4.5]decane carbon framework, was first isolated in 1970 by the research group of Tomita from the wood of Juniperus rigida. Recently, in 2003, Braun and coworkers reported the isolation of epi α- and epi β-acorenols along with α- and β-acorenols from the sandal wood oil Santalum spicatum. Total synthesis of all the four acorenols has been described in the first part of the first chapter of the thesis. Initially, a model study has been carried out for the spirocyclopentannulation of cyclohexanone employing a combination of Ireland ester Claisen rearrangement and ring closing metathesis reaction to furnish methyl 4-methylspiro[4.5]dec-3-en-1-carboxylate. The same methodology has been extended for the total synthesis of all the four acorenols starting from cyclohexane-1,4-dione via cis and trans isomers of methyl 4-methyl-8-methylene-spiro[4.5]dec-3-ene-1-carboxylate. Total synthesis of β-chamigrene, γ-chamigrene and laurencenone C, containing spiro[5.5]undecane carbon framework, has been described in the second part of the first chapter. As a model study, cyclohexanone has been transformed into 1,5,5-trimethylspiro-[5.5]undec-4-en-3-one employing a combination of Ireland ester Claisen rearrangement and intramolecular type-II carbonyl ene reactions. The methodology has been extended to chamigrenes starting from cyclohexane-1,4-dione via methyl 2-(1-isopropenyl-4-oxocyclo-hexyl)-2-methylpropanoate and 5,5-dimethyl-1,9-ismethylenespiro[5.5]undecan-3-ol. The marine sesquiterpenes laurokamurenes were first isolated in 2006 by Mao and Guo from Laurencia okamurai Yamada. First total synthesis of (±)-laurokamurene B has been described in the first part of the second chapter. To begin with Ireland ester Claisen rearrangement of but-2-enyl 2-methylpropionate furnished methyl 2,2,3-trimethylpent-4-enoate, which was then transformed into 4,5,5-trimethyl-3-(4-methylphenyl)hepta-1,6-dien-3-ol. RCM reaction followed by reductive deoxygeneation transformed 4,5,5-trimethyl-3-(4-methylphenyl)hepta-1,6-dien-3-ol into (±)-laurokamurene B. Subsequently, an enantioselective total synthesis of (+)-laurokamurene B has been accomplished. Stereoselective hydrogenation of methyl campholenoate furnished methyl 2-[(1S,3S)-2,2,3-trimethyl-cyclopent-1-yl]acetate, which was then transformed into (+)-laurokamurene B via degradation of the two carbon side chain and introduction of the aryl moiety, which established the absolute configuration of laurokamurenes. The third chapter deals with the enantiospecific generation of ABC-ring system of A-nor and abeo 4(3 → 2) tetra and pentacyclic triterpenes. To begin with (R)-carvone was identified as B-ring of ABC-ring system of A-nor and abeo tetra and pentacyclic triterpenes, as the absolute configuration at the C-5 position of the targets correlate to the stereo centre of carvone, and isopropenyl group can serve as the C-4 carbon of the targets along with the two gem-dimethyl groups. A lithium liquid ammonia mediated cyclisation of δ,ε-unsaturated esters was employed for the construction of the A ring and an RCM reaction was opted for the construction of the C ring. (R)-Carvone has been converted into 2-(1-ethoxyethoxy)-1,3,7,7-tetramethylbicyclo[4.3.0]non-3-en-8-ol via lithium liquid ammonia mediated cyclisation of methyl 2-(1-ethoxyethoxy)-6-isopropenyl-1,3-dimethylcyclohex-3-enyl]acetate, which was then transformed into 4-methoxymethoxy-2,5,5,9-tetramethyltricyclo[7.4.0.02,6]tridec-11-en-8-one via the RCM reaction of 3,4-bisallyl-8-methoxymethoxy-4,6,9,9-tetramethylbicyclo-[4.3.0]nonan-3-one. The strategy has been further extended to the synthesis of 4-methylene-2,5,5,9-tetramethyltricyclo[7.4.0.02,6]tridec-11-en-8-one, which contains the ABC ring system of abeo 4(3→2) tetra and pentacyclic triterpenes.

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.

Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-05-03T18:31:57Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) renata_couto_avila.pdf: 1413291 bytes, checksum: 669e7c9a25e57d1c58d553d00cbb588a (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-05-17T12:06:16Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) renata_couto_avila.pdf: 1413291 bytes, checksum: 669e7c9a25e57d1c58d553d00cbb588a (MD5) / Made available in DSpace on 2017-05-17T12:06:16Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) renata_couto_avila.pdf: 1413291 bytes, checksum: 669e7c9a25e57d1c58d553d00cbb588a (MD5) Previous issue date: 2016 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / 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.

Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2013-04-03T14:46:18Z No. of bitstreams: 2 tese-Isley Fehlberg v1.pdf: 2026726 bytes, checksum: 5d2210e3344984bf208412e2419faae9 (MD5) Tese Isley Fehlberg Anexos.pdf: 28821560 bytes, checksum: 48517fb7676ccbd2c9605fcf24ff900c (MD5) / Approved for entry into archive by Ana Hilda Fonseca(anahilda@ufba.br) on 2013-04-15T14:23:54Z (GMT) No. of bitstreams: 2 tese-Isley Fehlberg v1.pdf: 2026726 bytes, checksum: 5d2210e3344984bf208412e2419faae9 (MD5) Tese Isley Fehlberg Anexos.pdf: 28821560 bytes, checksum: 48517fb7676ccbd2c9605fcf24ff900c (MD5) / Made available in DSpace on 2013-04-15T14:23:54Z (GMT). No. of bitstreams: 2 tese-Isley Fehlberg v1.pdf: 2026726 bytes, checksum: 5d2210e3344984bf208412e2419faae9 (MD5) Tese Isley Fehlberg Anexos.pdf: 28821560 bytes, checksum: 48517fb7676ccbd2c9605fcf24ff900c (MD5) / 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

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.

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).