One area of natural product synthesis which has been heavily investigated in the last eight decades is the total synthesis of terpenoids. Among terpenoids, the presence of a great deal of stereochemical complexity in combination with a variety of functionalities makes sesquiterpenes challenging targets to the synthetic chemists. As a result synthetic activity in this area continues to flourish. The thesis entitled “Enantiospecific Synthesis of Guaianes and Tricyclic Ring Systems of Elisabethins and Dumsins’’ describes the studies directed towards the synthesis of the guaiane sesquiterpenes and exploratory studies towards elisabethins and dumsin diterpenoids. For convenience, the results are presented in two chapters; viz (1) Enantiospecific Total Synthesis of Guaiane Sesquiterpenes; and (2) Enantiospecific Synthesis of ABC Ring System of the Diterpenoids Elisabethins and Tetranortriterpenoids Dumsins. 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. Clavukerin A, the first member of the trisnorguaianes, was simultaneously isolated in 1983 by the research groups of Kitagawa from the Okinawan soft coral Clavularia koellikeri (stolonifer), and Bowden from the Australian soft coral Cespituloria sp. In 1992, Kakisawa and his research group reported the isolation of isoclavukerin A from the Okinawan soft coral Clavularia sp. In the present thesis, formal total syntheses of clavukerin A and isoclavukerin A have been described in the first part of the first chapter. To begin with, (R)-limonene has been transformed into 1-[5-isopropenyl-2-methylcyclopent-1-en-1-yl]pent-4-en-1-one via the 5-isopropenyl-2-methyl-cyclopent-1-en-1-carboxaldehyde. RCM reaction of the enone produced 6,10-dimethylbicyclo[5.3.0]deca-1(10),5-dien-2-one, which on epoxidation generated 1-[(1S,2S,5R) and (1R,2S,5S)-2-isopropenyl-5-methyl-6-oxabicyclo[3.1.0]hex-1yl]pent-4-en-1-ones. These epoxy ketones were then transformed into (6S,7S) and (6R,7S)6,10-dimethylbicyclo[5.3.0]dec-1(10)-en-2-ones, thus completing the formal total synthesis of clavukerin A and isoclavukerin A. In the subsequent parts of the first chapter, enantiospecific total syntheses of the guaiane sesquiterpenes, aciphyllenes A and B, isocalamusenone and 6-epiisocalamusenones, and (6S)- and (6R)-11-hydroxyguaiadienes have been described. Aciphyllene A was isolated in 1983 by Kubota and co-workers from the essential oil of the roots of Lindera glauca. Aciphyllene B was isolated by Konig et al. in 1998 from the liverwort D. hirusta. In 1979, Rohr and co-workers reported the isolation of isocalamusenone from the plant Acorus calamus L, In 2000, Nkunya and colleagues isolated (6R)-11-hydroxyguaiadiene from the root bark of Lettowianthus stellatus, whereas (6S)-11-hydroxyguaiadiene was isolated in 1977 by Bohlmann et al. from the roots of Parthenium hysterophorus. The 5isopropenyl-2-methyl-cyclopent-1-en-1-carboxaldehyde derived from (R)-limonene has been converted into the (3R,4S,6S,7S)- and (3R,4S,6R,7S)-3-acetyl-6,10 dimethylbicyclo[5.3.0]dec1(10)-en-4-ols employing a type II carbonyl ene reaction and Wilkinson’s hydrogenation as the key steps, which have been further converted into aciphyllenes A and B along with their C-6 epimers, (+)-isocalamusenone, 6-epi-isocalamusenone, and (6S)- and (6R)-11-hydroxyguaiadienes. In the second chapter of the thesis, enantiospecific synthesis of the ABC-ring systems of elisabethin group of diterpenoids and tetranortriterpenoids dumsins have been described, starting from the readily available monoterpene (R)-carvone. To begin with, (R)-carvone has been transformed into 1,6,6-triallylcarveol, which on two simultaneous RCM reactions generated the ABC-ring system of the elisabethin group of diterpenoids. An alternative synthetic strategy was also developed for the same compound. Thus, first (R)-carvone has been transformed into 6-allyl-10-isopropenyl-7-methylspiro[4.5]deca-2,7-dien-6-ol, which on ROM-RCM reaction generated the requisite tricyclic alcohol, which on oxidation generated 4,8-dimethyltricyclo[7.4.0.01,5]trideca-3,8,11-trien-7-one, which represents the ABC ring system of elisabethins. Introduction of the second allyl group at the C-7 position of 6-allyl-10isopropenyl-7-methylspiro[4.5]deca-2,6-dien-8-one followed by RCM reaction resulted in the formation of the tricyclic ketones (1S,4S,6R) and (1R,4S,6R)-4-isopropenyl-1-methylbicyclo[4.4.0]decanespiro[5,1']-cyclopenta-3',8-diene-2-ones, which represents the ABC ring system of tetranortriterpenoids dumsins.

No description available.

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.

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.

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.

Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2017-05-29T18:25:32Z No. of bitstreams: 2 Dissertação - Henrique Pascoa - 2012.pdf: 942408 bytes, checksum: b56d72ecf335473b883c3690ab686dd8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-30T10:33:28Z (GMT) No. of bitstreams: 2 Dissertação - Henrique Pascoa - 2012.pdf: 942408 bytes, checksum: b56d72ecf335473b883c3690ab686dd8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-05-30T10:33:28Z (GMT). No. of bitstreams: 2 Dissertação - Henrique Pascoa - 2012.pdf: 942408 bytes, checksum: b56d72ecf335473b883c3690ab686dd8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2012-02-27 / 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.

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.

Accurate measurements of ammonia, nitric acid and formic acid are important for achieving a complete understanding of their atmospheric role. Models and measurements of formic acid in the atmosphere continue to show disagreements. Also, the contributions of NMHCs and reactive nitrogen (HNO3 and NH3) to organic and inorganic aerosol formation are important to quantify as gaps in the knowledge of atmospheric aerosols are a source of uncertainty in climate science. In this thesis, concentrations of ammonia were measured in the atmosphere and the production of formic acid from the ozonolysis of isoprene was measured in the EXTRA (EXTreme RAnge) chamber. Both gases were studied using chemical ionisation mass spectrometry (CIMS). The kinetics of the reactions of sesquiterpenes and terminal alkenes with ozone were studied in theEXTRA chamber using the relative rates technique and GC-FID. The ozonolysis rate coefficients of a homologous series of terminal alkenes were measured at elevated temperatures and found to be invariant with the carbon number. This led to the conclusion that previous measurements of these rate coefficients were subject to experimental artefacts. The elevated temperature protocol was employed to study the ozonolysis of sesquiterpenes, leading to revisions in ko3 for β-caryophyllene and α-humulene of 3 orders of magnitude. It was thus concluded that ozonolysis only accounts for 9-15% of sesquiterpeneoxidation in the atmosphere. A field intercomparison of CIMS for measuring ammonia was conducted wherein CIMS was found to perform well alongside instruments of comparable time response and limits of detection. This thesis also characterised inlet materials used in atmospheric measurements in the first systematic study on the uptake onto inlet walls in a flow tube system coupled to CIMS. It was found that PFA is the preferable material for atmospheric measurements, both for its kinetic qualities and its ready availability and ease of use. Finally, CIMS was used to measure the yield of formic acid from isoprene ozonolysis as a function of relative humidity. Formic acid yield was found to increase between 0-40% RH to a maximum of 0.18. Using the measured formic acid yields in a global chemistry model leads to an estimate that formic acid production from isoprene ozonolysis is ~9.5 Tg yr-1.

Flüchtige organische Verbindungen (volatile organic compounds, VOCs) haben vielseitige Funktionen in der Biosphäre und Atmosphäre. VOCs sind an ober- und unterirdischen Interaktionen beteiligt. Zum Beispiel können von Mikroorganismen emittierte VOCs das Pflanzenwachstum beeinflussen und von Pflanzen emittierte VOCs sich auf das Verhalten von Pathogenen und Herbivoren auswirken. Nur wenig ist über die Rolle von VOCs in der Kommunikation von Ektomykorrhizapilzen (EMF) mit ihren Wirtspflanzen bekannt. EMF gehen Symbiosen mit Baumarten wie Pappeln (Populus spp.) ein. Pappeln sind als Biomasseproduzenten von großer ökonomischer Bedeutung, emittieren jedoch eine hohe Konzentration des klima-relevanten VOCs Isopren in die Atmosphäre. Die Rolle von Isopren in biotischen Interaktionen von Pappeln mit Herbivoren ist unklar. Zudem ist es wichtig zu verstehen wie EMF-Inokulation den Metabolismus von Pappeln und dadurch deren oberirdische Interaktion beeinflussen. Hauptziel dieser Arbeit war es, die Kommunikation durch VOCs zwischen Pflanzen und Pilzen zu untersuchen. Zu diesem Zweck wurden die Modellarten Laccaria bicolor und Populus × canescens verwendet. Um die Spezifität von VOC-Mustern sowie Pflanzen-Reaktionen zu untersuchen, wurden einige andere EMF und nicht-Mykorrhiza bildende Pilze getestet sowie die Nicht-Wirtspflanze Arabidopsis verwendet. Um die Bedeutung von Isopren oder EMF auf oberirdische Herbivorie zu untersuchen, wurde die Präferenz des Pappelblattkäfers (Chrysomela populi) und des Weidenblattkäfers (Phrotara vitellinae) für nicht-Isopren emittierende Pappeln überprüft. Insbesondere wurden folgende Fragestellungen untersucht: i) Können EMF und Pilze anderer Lebensweisen aufgrund ihrer VOC-Emissions-Muster voneinander unterschieden werden? ii) Sind pilzliche VOCs an der Erkennung von EMF durch Pappel und Arabidopsis beteiligt und wenn dies zutrifft, welche Verbindungen der Volatilen-Mischung sind an der Reaktion beteiligt? iii) Ist die Isopren-Emission von Pappeln für die Orientierung von Pappelblattkäfern von Bedeutung? iv) Beeinflusst eine Inokulation von Pappeln mit EMF die Abwehr gegen den Pappelblattkäfer C. populi und wenn, welche Transkriptionsveränderungen in den Blättern von EMF-inokulierten im Vergleich zu nicht-inokulierten Pflanzen sind an dieser Reaktion beteiligt? Untersuchungen über Mykorrhiza-Interaktion mit Pappeln erfordern kontrollierte Kultivierungs-Systeme. Daher werden detaillierte Protokolle für die Anzucht von Pappelarten mit und ohne EMF unter axenischen und Freiland-Bedingungen angegeben. Zur Untersuchung der Interaktion zwischen Pappeln und EMF werden zwei-geteilte Wachstumssysteme für die Kultivierung der Pflanzen ohne direkten Kontakt zu EMF beschrieben. i) Um die Spezifität und Gemeinsamkeiten von VOCs von EMF und anderen, nicht-Mykorrhiza bildenden Pilzen zu untersuchen, wurden VOC-Muster von Pilzen verschiedener Lebenssweisen verglichen. In der vorliegenden Arbeit wurden die VOC-Emissionen der drei EMF Cenococcum geophilum, L. bicolor und Paxillus involutus (Stämme MAJ und NAU), der drei Pathogene Armillaria mellea, Pholiota squarrosa und Verticillium longisporum sowie der zwei Saprophyten Stropharia rugosoannulata und Trichoderma viride im Gasraum der Kulturen gesammelt. Die Pilze wurden in Petrischalen auf einem synthetischen Medium, welches eine geringe eigene VOC-Emission aufwies, angezogen. Alle VOCs, welche in Kontrollschalen ohne Pilz gemessen wurden, wurden aus dem Datensatz entfernt. Nach Entfernung dieser 40 Hintergrund-VOCs der Kontrollplatten verblieben 54 Pilz-VOCs. Die untersuchten Pilze unterschieden sich stark in ihrem VOC-Emissions-Profil. Nur 15 VOCs wurden bei allen Lebensweisen identifiziert; darunter die typische Pilz-VOC 1-octen-3-ol. Fünfzehn VOCs wurden zuvor noch nicht bei Pilzen gemessen und einige VOCs wurden nur bei einem Pilz oder einer Lebensweise gefunden. Insbesondere die Emission der Sesquiterpene (SQTs) unterschied sich stark zwischen den Pilzen. Multivariate Analysen der VOC-Profile gruppierte die Pilzarten nach ihren Lebensweisen. ii) Zur Ermittlung, ob Pilz-VOCs wichtige Signalstoffe für Pflanzen sind, unabhängig von ihrer Fähigkeit eine Mykorrhiza bilden zu können, wurden die Wirtspflanze P. × canescens und die Nicht-Wirtspflanze A. thaliana VOCs der EMF L. bicolor und C. geophilum ausgesetzt. Pflanzen und Pilze wurden in einem geschlossenen System mit zwei separaten Kompartimenten und gemeinsamem Gasraum kultiviert. Sammeln der Pilz-VOC-Emissionen in den Kontrollplatten mit den Pflanzen zeigte, dass Arabidopsis nur wenige VOCs emittierte, wohingegen sowohl in den Kulturen von L. bicolor als auch in der gemeinsamen Kultur von L. bicolor mit Pflanzen vor allem SQTs detektiert wurden. Die Seitenwurzelbildung von Arabidopsis und Pappel wurde durch L. bicolor-VOCs angeregt. C. geophilum, welcher nicht fähig ist SQTs zu bilden, hatte keine Wirkung auf die Wurzelstruktur. Unterdrückung der SQT-Synthese in L. bicolor durch Inhibierung des Mevalonat-Biosyntheseweges mit Lovastatin verminderte die Stimulierung der Seitenwurzelbildung signifikant. Diese Ergebnisse deuten darauf hin, dass pilzliche SQTs Seitenwurzelbildung auslösen. Das schwach emittierte Thujopsen stimulierte die Seitenwurzelbildung sowohl in Abwesenheit des Pilzes als auch bei einer Unterdrückung der SQT-Biosynthese des Pilzes durch Lovastatin. Das SQT β-Caryophyllene hatte keinen Einfluss auf die Wurzelstruktur. Diese Arbeit zeigt, dass pilzliche SQTs, darunter das spezifische Thujopsen, wichtige Signalstoffe in der Interaktion zwischen EMF und Wirts- sowie Nicht-Wirtspflanzen darstellen. iii) Die Käfer C. populi und P. vitellinae sind typisch vorkommende Schädlinge in Pappelplantagen und können signifikante ökonomische Verluste verursachen. Zur Ermittlung, ob von Pappelblättern emittiertes Isopren von C. populi und P. vitellinae Käfern wahrgenommen wird und eine Rolle bei der Orientierung dieser Käfer spielt, wurden verschiedene Fraßversuche mit den Käfern und Isopren-emittierenden und transgenen nicht-Isopren-emittierenden Pappeln durchgeführt. Sowohl in Gewächshaus- als auch in Laborversuchen zeigten weder die Larven noch die Käfer eine Präferenz für Isopren-emittierende oder nicht-emittierende Linien. Unerwarteter Weise wurden eine verstärkte Eiablage und ein höherer Fraßschaden auf Isopren-emittierenden gegenüber nicht-emittierenden Linien unter Freilandbedingungen festgestellt. Metabolomanalysen wiesen auf Veränderungen in den Blättern, welche von der Pappellinie abhängig waren, und auf Effekte auf Terpen-Muster hin. Die Käfer waren in der Lage verschiedene Terpene wahrzunehmen, waren aber nicht in der Lage Isopren wahrzunehmen. Daher könnten kleine Veränderungen der VOC-Emission in den transgenen nicht-Isopren emittierenden Pappellinien durch Unterdrückung der Isopren-Produktion und/oder ausgelöste Veränderungen im Metabolom-Profil die Käfer-Präferenz verändert haben. Obwohl das Hauptziel der Untersuchung - Isopren - keinen Einfluss auf das Käferverhalten hatte, wurde das Käferverhalten auf den Pappeln durch Konsequenzen der Modifikation beeinflusst. Das Ausmaß dieses Effektes war jedoch marginal. iv) Unter natürlichen Bedingungen interagieren Pappeln zeitgleich mit unterirdischen und oberirdischen Organismen. Zur Untersuchung, ob eine Inokulation von Pappeln mit EMF in den Blättern molekulare Veränderungen hervorruft und ob diese Veränderungen das Verhalten von Pappelblattkäfern beeinflussen, hatten C. populi-Käfer die Wahl zwischen Pappeln, welche mit L. bicolor inokuliert waren, und solchen, die nicht inokuliert waren. C. populi präferierten die Nicht-inokulierten sowohl als Nahrung als auch zur Eiablage. RNA-Sequenzierung des Blatttranskriptoms deutete an, dass der Käferbefall eine starke Abwehrreaktion in den Pflanzen auslöste. Auch die EMF-Inokulation beeinflusste das Blatt-Transkriptom, jedoch nur von wenigen Genen. Im Vergleich zu den nicht-inokulierten Pappeln wiesen die inokulierten Pappeln verringerte Transkript-Abundanzen von Genen des Abscisinsäure-Signalweges und der Flavonoid-Biosynthese sowie erhöhte Transkript-Abundanzen der Biosynthesegene von Aldoximen auf, welche kürzlich als Abwehrstoffe identifiziert wurden. Diese Ergebnisse lassen vermuten, dass EMF die Abwehr gegen Herbivore aktivieren und dadurch den natürlichen Schutz von Pappeln verbessern. In jungen Pappeln verursachen EMF jedoch auch ein signifikant geringeres Wachstum. Zusammenfassend zeigen die Ergebnisse dieser Dissertation, dass EMF-VOC-Profile sich von jenen anderer Pilze oder anderer Lebensweisen unterscheiden und dass eine bestimmte chemische Gruppe, die SQTs, als Signalmoleküle in frühen Interaktionen mit Pflanzen fungieren. Zum ersten Mal konnte eine Pilz-VOC, Thujopsen, identifiziert werden, welche für die Stimulierung der Seitenwurzelbildung in Pflanzen verantwortlich ist. Es wurde gezeigt, dass die Haupt-Pappel-VOC Isopren nur eine geringe Rolle in oberirdischen Interaktionen mit dem Herbivoren C. populi spielt. EMF führten zu Transkriptveränderungen in Pappelblättern und einer reduzierten Attraktivität für C. populi Käfer. Die Ergebnisse dieser Dissertation können für biotechnologische Verbesserungen von Pappeln und verstärktem Schutz von Pappeln in Biomasseplantagen verwendet werden.

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.