FundaÃÃo de Amparo à Pesquisa do Estado do Amazonas / Aspidosperma ulei Markgr, popularmente conhecida como pitià ou piquiÃ, apresenta-se como uma Ãrvore com casca Ãspera e acinzentada. No presente trabalho foi realizado o estudo fitoquÃmico dos extratos etanÃlicos das folhas de Aspidosperma ulei, alÃm de uma reinvestigaÃÃo fitoquÃmica do caule e raiz de um espÃcime coletado na localidade Garapa, MunicÃpio de Acarape, no estado do CearÃ. Para os extratos etanÃlicos dos lenhos do caule e raiz e da casca da raiz foram realizados tratamentos por extraÃÃo Ãcido/base para obtenÃÃo das fraÃÃes alcaloÃdicas. Para as folhas e a casca do caule, alÃquotas dos extratos etanÃlicos de ambas foram submetidas a cromatografias convencionais sobre sÃlica gel e por CLAE, possibilitando o isolamento do triterpeno Ãcido ursÃlico, um derivado do inositol, o metil-chiro-inositol e dos alcaloides indÃlicos β-ioimbina, ioimbina, 3,4,5,6-tetra-desidro-β-ioimbina, 19,20-desidro-17α-ioimbina e 19(E)-hunteracina. Das fraÃÃes alcaloÃdicas dos lenhos do caule e da raiz foram obtidos por CLAE, 20(E)-17-nor-subincanadina E, relatado pela primeira vez como produto natural, alÃm do Ãcido 12-hidroxi-N-acetil-21(N)-desidro-plumerano-18-Ãico, um alcaloide indÃlico tambÃm inÃdito como produto natural. Da fraÃÃo alcaloÃdica da casca da raiz foram obtidos por CLAE a uleÃna, 20-epi-dasicarpidona, 20-epi-N-nordasicarpidona, N-desmetiluleÃna, olivacina e a δ-lactona booneÃna. O Ãcido ursÃlico e a 20(E)-17-nor-subincanadina E foram submetidos a testes de atividade citotÃxica e apresentaram resultados significativos frente a 4 linhagens de cÃlulas tumorais. A identificaÃÃo e caracterizaÃÃo dos compostos isolados foram realizadas por tÃcnicas espectroscÃpicas como IV, EM e RMN uni e bidimensional, inclusive tÃcnicas como HSQC, NOESY, COSY e HMBC, alÃm de comparaÃÃo com dados da literatura. / Aspidosperma ulei Markgr. popularly known as pitià or piquiÃ, is a tree of a rough and gray trunk bark. This work reports the phytochemical analysis of the leaves, and the re-investigation of the trunk and roots of an A. ulei specimen collected at the locality of Garapa- Acarape Country â Cearà State. The ethanol extracts of all parts were obtained. Acid/base extraction was performed with the extracts from the trunk and root heartwoods and root bark, in order to obtain the alkaloids fraction. For the leaves and trunk bark small portions of the ethanol extract were submitted to conventional chromatography over silica gel followed by semipreparative HPLC to afford the triterpene ursolic acid, an inositol derivative the methyl-chiro-inositol, and the alkaloids β-yohimbine, yohimbine, 3,4,5,6-tetradehydro-β-yohimbine, 19,20-dehydro-α-yohimbine and 19(E)-hunteracine. From the alkaloidal fractions of the trunk and the root heartwood, were obtained, by semi preparative HPLC, the alkaloids 20(E)-17-nor-subincanadine E, reported for the first time for the species and also an natural product, and the 12-hydroxy-N-acetyl-21(N)-dehydro-plumeran-18-oic acid, on unknown indole alkaloid. From the alkaloidal fraction of the root bark, after semipreparative HPLC, were obtained the indole alkaloids uleine, 20-epi-dasycarpidone, 20-epi-N-nordasycarpidone, N-noruleine, olivacine and the booneine lactone. Ursolic acid and 20(E)-17-nor-subincanadine E were assayed as citotoxic and showed significative results against four tumour cell lines. The identification and characterization of all compounds were realized by means of spectroscopic techniques such as IR, MS and uni and bidimensional NMR, including pulse sequences such as HSQC, NOESY, COSY and HMBC, after comparison to the literature data.

The focus of this thesis was to study the chemotaxonomic relationship of selected southern Australian marine brown algae of the genera Cystophora and Sargassum. Consequently, this resulted in the isolation and structure elucidation of six new terpenoids from two southern Australian marine brown algae Cystophora moniliformis and Sargassum fallax together with 10 previously reported natural products. As a result of the re-isolation of these known secondary metabolites, updated and complete structural characterisation data could be provided for the first time for 7 of these compounds. Chemotaxonomic studies of Cystophora moniliformis resulted in the isolation of two new cyclic epimeric terpene diols moniliforminol A (3.25) and moniliforminol B (3.26), a new linear farnesyl acetone derivative (3.27) and the previously described terpenoids (3.19)-(3.24). This study also resulted in the first complete 2D NMR characterisation for compounds (3.21) to (3.24) as well as the first report of (3.24) occurring as a natural product. All structures were elucidated by detailed spectroscopic analysis with the relative configurations of (3.25) and (3.26) being established by selective 1D nOe NMR experiments. The proposed biosynthetic pathway for the above compounds has also been described. Chemical investigation of the Southern Australian marine brown alga Sargassum fallax resulted in the isolation of three new meroditerpenoids fallahydroquinone (4.8), fallaquinone (4.9) and fallachromenoic acid (4.10), together with the previously reported compounds sargaquinone (4.1) (isolated and identified in a mixture with sargaquinoic acid), sargahydroquinoic acid (4.2), sargaquinoic acid (4.3) and sargachromenol (4.11). As a result of this study the complete 2D NMR characterisation for sargahydroquinoic acid (4.2) and sargaquinoic acid (4.3) could also be reported for the first time. All structures were elucidated by detailed spectroscopic analysis. Sargahydroquinoic acid (4.2) and sargaquinoic acid (4.3) displayed moderate antitumour activity.

A química de produtos naturais sempre foi uma fonte importante de novas substâncias e de substâncias bioativas. No mundo moderno, o homem utiliza os produtos naturais para diversos fins: corantes, edulcorantes, essências, defensivos agrícolas e principalmente medicamentos. Com o desenvolvimento das técnicas de isolamento de substâncias, cresceu a necessidade de organizar as informações obtidas e também a criação de meios para a identificação mais rápida das substâncias isoladas. Esta foi uma das necessidades que fez surgir a Quimioinformática. Quimioinformática é uma disciplina que utiliza os métodos da informática para organizar dados químicos, analisar estes dados e gerar novas informações a partir destes dados. Esta ferramenta tem sido utilizada com sucesso em procura por novas drogas (QSAR/QSPR), elucidação estrutural automatizada de substâncias orgânicas e em cálculos e previsão de propriedades físico-químicas de diversas moléculas. Os objetivos do presente trabalho foram o estudo fitoquímico de espécies dos gêneros Dimerostemma e Ichthyothere com o intuito de isolar novas substâncias e o desenvolvimento de técnicas envolvendo quimioinformática com o intuito de auxiliar a elucidação estrutural de produtos naturais. Realizou-se a técnica de microamstragem de tricomas glandulares de diversas espécies pertencentes a gêneros da tribo Heliantheae (Viguiera, Tithonia, Dimerostemma). Através da microamostragem foi possível identificar diversas substâncias presentes nos tricomas glandulares das espécies analisadas. Das duas espécies de Dimerostemma investigadas (D. brasilianum e D. rotundifolium) foi possível identificar dois germacrolidos e dois eudesmanolidos, enquanto que de Ichthyothere terminalis foi possível a identificação de dois melampolidos, todos eles lactonas sesquiterpênicas. Foram treinadas redes neurais artificiais para a realização da identificação dos esqueletos carbônicos de determinadas substâncias a partir dos dados obtidos através dos espectros de RMN 13C, sendo que os resultados obtidos podem ser considerados satisfatórios. Foi desenvolvido um software para efetuar a identificação automática de substâncias através da comparação com uma biblioteca de padrões que possui dados cromatográficos de 51 lactonas sesquiterpênicas. Esse software, chamado de NAPROSYS, também é capaz de fazer comparação de dados de RMN de amostra com dados de RMN presentes em uma biblioteca de dados, tornando possível a identificação imediata de substâncias presentes na biblioteca e também auxiliar a elucidação estrutural de substâncias que não estão nela presentes. Para testar a eficiência do NAPROSYS, o programa foi utilizado com sucesso para identificar LSTs através da microamostragem de tricomas glandulares. A eficiência do NAPROSYS em identificar dados de RMN de substâncias presentes na biblioteca foi testada com substâncias isoladas do gênero Tithonia e Viguiera que possuem substâncias bem descritas na literatura e já isoladas no nosso laboratório, sendo que os resultados apresentados foram excelentes. Criou-se também dois modelos de redes neurais para prever tempos de retenção de lactonas sesquiterpênicas em cromatografia líquida (QSRR) com o objetivo de melhorar o desempenho do NAPROSYS em análises de dados cromatográficos. Os resultados para este caso, embora coerentes, precisam ser melhorados. Neste trabalho concluimos que o uso das técnicas clássicas juntamente com as novas técnicas de Quimoinformática pode se tornar uma ferramenta muito eficaz para a elucidação estrutural e busca de substâncias com determinadas propriedades químicas ou mesmo na bioprospecção de novas substâncias bioativas. / Natural products chemistry has always been an important source for new andbioactive compounds. In modern world, mankind uses natural products to do many tasks: colouring, as essences, as agricultural defensives and many as medicines. Within the development of compound isolation techniques, the need for information organisation has grown. The need for quickly identification of isolated compounds has also grown. This was one of the necessities that made Chemoinformatics emerge. Chemoinformatics is a discipline that uses informatics as a tool to organise, analise and to generate new knowledge from chemical data. This tool has been used with success in automate structure elucidation, drug development (QSAR/QSPR) and to predict chemical-physical data of many molecules. The aims of the present work were the phytochemical study of species of the genera Dimerostemma and Ichthyothere to isolate new compounds, and the development of chemoinformatics techniques to aid natural products structure elucidation. The glandular trichome microsampling was made for diverse species of genera from the tribe Heliantheae (Viguiera, Tithonia, Dimerostemma). Many compounds were identified through glandular trichome microsampling. Two germacrolides and two eudesmanolides were identified from Dimerostemma species (D. brasilianum and D. episcopale), while from Ichthyothere terminalis two melampolides were identified, all of them being sesquiterpene lactones. Artificial Neural Networks were trained to make skeleton identification from data obtained from 13C NMR and the obtained results can be considered satisfactory. A software was developed to make automatic compound identification through the comparation with a compound library that possesses data from 51 STLs. This software is called NAPROSYS is also able to compare the NMR data of the sample with the NMR data stored into a compound library, making the imediate identification of compounds present into library possible and also help the structure elucidation of unknown compounds. To test NAPROSYS\' efficience to identify NMR data of compunds sored into the library was made with compounds isolated from species of Tithonia and Viguiera genera, because these genera has well describe compounds in the literature and that has been isolated in our laboratory, and the obtained results are excellent. Two Artificial Neural Network models were created to predict the retention time of sesquiterpene lactones in liquid cromatography (QSRR) with the aim of improve NAPROSYS performance in cromatographic data analysis. The results for this case, although coherent, can be improved. The conclusion of this work is that the use of classical techniques with the new techniques of chemoinformatics can be a very efficient tool to make structure elucidation, search for compounds with certain chemical properties and even the search for new bioactive compounds.

Carbohydrates are ubiquitous components in nature involved in a range of tasks. They cover every cell and contribute both structural stability as well as identity. Lipopolysaccharides are the outermost exposed part of the bacterial cell wall and the primary target for host-pathogen recognition. Understanding the structure and biosynthesis of these polysaccharides is crucial to combat disease and develop new medicine. Structural determinations can be carried out using NMR spectroscopy, a powerful tool giving information on an atomistic scale. This thesis is focused on method development to study polysaccharide structures as well as application on bacterial lipopolysaccharides. The focus has been to incorporate a bioinformatics approach prior to analysis by NMR spectroscopy, and then computer assisted methods to aid in the subsequent analysis of the spectra. The third chapter deals with the recent developments of ECODAB, a tool that can help predict structural fragments in Escherichia coli O-antigens. It was migrated to a relational database and the aforementioned predictions can now be made automatically by ECODAB. The fourth chapter gives insight into the program CASPER, a computer program that helps with structure determination of oligo- and polysaccharides. An approach to determine substituent positions in polysaccharides was investigated. The underlying database was also expanded and the improved capabilities were demonstrated by determining O-antigenic structures that could not previously be solved. The fifth chapter is an application to O‑antigen structures of E. coli strains. This is done by a combination of NMR spectroscopy and bioinformatics to predict components as well as linkages prior to spectra analysis. In the first case, a full structure elucidation was performed on E. coli serogroup O63, and in the second case a demonstration of the bioinformatics approach is done to E. coli serogroup O93. In the sixth chapter, a new version of the CarbBuilder software is presented. This includes a more robust building algorithm that helps build sterically crowded polysaccharide structures, as well as a general expansion of possible components. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 5: Manuscript.</p>

5 Abstract The formerly reported hydroxyamide Ph2PfcC(O)NHCH2CH2OH 1 and its respective novel congeneric analogues Ph2PfcC(O)NHCH3−n(CH2OH)n (3: n = 2; 4: n = 3) were used to prepare a series of arene-ruthenium(II) complexes [(η6 -arene)RuCl2(L-κP)] 6-8 (arene = C6H6, p-cymene, C6Me6; L = 1, 3 or 4). These complexes were studied as pre-catalysts in redox isomerization of allylic alcohols to carbonyl compounds. Among the compounds prepared, complex 6b [(η6 -p-cymene)RuCl2(1-κP)] showed best results. The solid state structure of the product of photolytic decomposition of complex [(η6 - C6Me6)RuCl2(2-κP)] (2 = Ph2PfcC(O)N(CH2CH2OH)2), viz, [(µ-Cl)3{Ru(η6 -C6Me6)}2] [FeCl4] 9, was determined by single-crystal X-ray diffraction analysis. The bis-phosphane complexes [MII Cl2(1-κP)2] (M = trans-Pd (10), cis-Pt (11) and trans- Pt (12)) together with chalcogenide derivatives Ph2P(O)fcC(O)NH(CH2)2OH (13) and Ph2P(S)fcC(O)NH(CH2)2OH (14) derived from hydroxyamide 1 were tested in vitro for their cytotoxicity against human ovarian A2780 cancer cell line. Complexes tested showed moderate cytotoxicity. Triol-amide FcC(O)NHC(CH2OH)3 15 (Fc = ferrocenyl) reacted with decavanadate (Bu4N)2[H3V10O28] at elevated temperature and prolonged reaction time yielding the hybrid hexavanadate (Bu4N)2[{FcC(O)NHC(CH2O)3}2V6O13] 16...

Carbohydrates are abundant in nature and have functions ranging from energy storage to acting as structural components. Analysis of carbohydrate structures is important and can be used for, for instance, clinical diagnosis of diseases as well as in bacterial studies. The complexity of glycans makes it difficult to determine their structures. NMR spectroscopy is an advanced method that can be used to examine carbohydrates at the atomic level, but full assignments of the signals require much work. Reliable automation of this process would be of great help. Herein studies of Escherichia coli O-antigen polysaccharides are presented, both a structure determination by NMR and also research on glycosyltransferases which assemble the polysaccharides. The computer program CASPER has been improved to assist in carbohydrate studies and in the long run make it possible to automatically determine structures based only on NMR data. Detailed computer studies of glycans can shed light on their interactions with proteins and help find inhibitors to prevent unwanted binding. The WaaG glycosyltransferase is important for the formation of E. coli lipopolysaccharides. Molecular docking analyses of structures confirmed to bind this enzyme have provided information on how inhibitors could be composed. Noroviruses cause gastroenteritis, such as the winter vomiting disease, after binding human histo-blood group antigens. In one of the projects, fragment-based docking, followed by molecular dynamics simulations and binding free energy calculations, was used to find competitive binders to the P domain of the capsid of the norovirus VA387. These novel structures have high affinity and are a very good starting point for developing drugs against noroviruses. The protein targets in these two projects are carbohydrate binding, but the techniques are general and can be applied to other research projects. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Submitted. Paper 5: Manuscript. Paper 6. Manuscript.

No description available.

No description available.

No description available.

Ce mémoire traite du développement d'outils informatiques d'aide à l'analyse structurale des petites molécules organiques par Résonance Magnétique Nucléaire (RMN). Il comprend deux volets axés sur l'automatisation de tâches auxquelles les chimistes des laboratoires de synthèse organique ou d'isolement de substances naturelles sont confrontés au quotidien, à savoir l'élucidation et la vérification de structure. Le premier volet concerne des améliorations apportées au logiciel de génération de structure LSD (Logic for Structure Determination). Ce logiciel est basé sur l'interprétation des corrélations des spectres de RMN 2D pour la détermination de structures complètement ou partiellement inconnues. Les progrès récents ont pour but d'augmenter la diversité des molécules analysables et d'améliorer le traitement des corrélations ainsi que la présentation des résultats. L'intégration de LSD avec la base de données SISTEMAT permet de bénéficier de la source d'information supplémentaire que constitue la valeur des déplacements chimiques. Cet avantage se traduit par un filtrage des solutions en fonction d'éléments de sous-structure sélectionnés dans une collection de squelettes de produits naturels. Le second volet présente le développement du logiciel CASA (Computer-Aided Spectral Assignment) dont le rôle est de réaliser une vérification automatique de structure par l'attribution des résonances. Il s'appuie sur des contraintes issues des spectres de RMN 2D et sur un module de prédiction des déplacements chimiques 13C. / This thesis deals with the development of computational tools for structural analysis of small organic molecules by Nuclear Magnetic Resonance (NMR). It consists of two parts that focus on the automation of tasks that chemists working in the fields of organic synthesis or natural substance isolation daily face, namely structure elucidation and verification. The first part reports improvements of the structure generation software LSD (Logic for Structure Determination). This software is designed for the determination of completely or partially unknown structures from the interpretation of 2D NMR correlation spectra. The present work aims to increase the diversity of the molecules that can be analyzed and to improve the processing of correlation data as well as the presentation of results. The integration of LSD with the SISTEMAT database introduces chemical shifts values as an additional information source. It allows the chemist to sort the possible solutions of a problem according to the presence of known natural product skeletons. The second part presents the development of the CASA (Computer-Aided Spectral Assignment) software as a tool for automatic structure assignment. It jointly makes use of constraints from 2D NMR spectra and from the matching between experimental and predicted 13C chemical shifts.