Conselho Nacional de Desenvolvimento Científico e Tecnológico / O ambiente marinho é um dos ecossistemas mais diversos e complexos em termos de biodiversidade. As condições químicas, físicas e biológicas desse ambiente favorecem a produção de uma variedade de substâncias pela biota, transformando os produtos naturais marinhos em um dos recursos promissores na pesquisa por novos compostos bioativos. O gênero Tubastraea (Scleractinia, Dendrophylliidae) inclui corais ahermatípicos que produzem compostos secundários bioativos em situações de competição. No estado do Rio de Janeiro são encontradas duas espécies invasoras desse gênero, Tubastraea coccinea e Tubastraea tagusensis. A primeira é amplamente distribuída nas águas tropicais do Atlântico e do Pacífico, e a segunda é nativa do leste do pacífico, ambas invasoras no Atlântico Sul. Este trabalho objetiva avaliar as atividades anti-inflamatória, antioxidante e toxicológica de extratos metanólicos de T. coccinea e T. tagusensis. As colônias de Tubastraea foram coletadas na Baía de Ilha Grande, Rio de Janeiro - Brasil e extraídas com metanol. A caracterização química foi realizada através da espectroscopia ultravioleta, visível e de infravermelho. Ação anti-inflamatória foi avaliada pelo modelo in vivo de edema em pata de camundongo induzido por carragenina. Atividade sequestrante de radicais livres foi avaliada pelo método do DPPH. Na avaliação toxicológica utilizamos o ensaio Salmonella/microssoma, na presença e ausência de ativação metabólica exógena, o teste in vitro de micronúcleo com células de macrófagos de rato e o teste de mortalidade com o microcrustáceo Artemia salina. Foi possível a distinção dos grupos químicos presentes nos extratos, com os resultados encontrados sendo corroborados com os presentes na literatura. Os extratos de ambas as espécies apresentaram inibição significativa no edema da pata nas doses testadas, em relação ao veículo. Ambos os extratos demonstraram capacidade pela captura do radical DPPH. Atividades citotóxica e mutagênica na ausência de metabolização exógena não foram observadas para as linhagens TA97, TA98 e TA102 nas duas espécies; para a TA100 o extrato de T. coccinea induziu citotoxidade na concentração de 50 g/placa. Os dois extratos induziram citotoxicidade na presença de metabolização exógena para a cepa TA98, tendo sido detectada também indução de mutagenicidade nesta linhagem para T. coccinea. Os extratos não foram capazes de induzir a formação de micronúcleos e não foram tóxicos para o microcrustáceo A. salina. A resposta inibitória do edema após 2 h da indução indica que os compostos presentes nos extratos atuam na segunda fase da inflamação, possivelmente pela inibição da produção de prostaglandinas. Os resultados sugerem que os extratos das espécies T. coccinea e T. tagusensis apresentam substâncias com potencial uso farmacológico, como agente anti-inflamatório e antioxidante. / The marine environment is one of the most diverse and complex ecosystems in terms of biodiversity. The conditions of chemical, physical and biological environment enables the production of a variety of substances by the biota, transforming the marine natural products resources on a promising research for new bioactive compounds. The genus Tubastraea (Scleractinia, Dendrophylliidae) includes ahermatypic corals that produce bioactive secondary compounds in competitive situations. In the state of Rio de Janeiro are found two invasive species of this genus, Tubastraea coccinea and Tubastraea tagusensis. The first is widely distributed in the tropical waters of the Atlantic and Pacific, and the second is native to the eastern Pacific, both are invasive in the South Atlantic. This study is focused on the anti-inflammatory, antioxidant and toxicological evaluation of methanol extracts of T. coccinea and T. tagusensis. Tubastraea colonies were collected in the Ilha Grande Bay, Rio de Janeiro - Brazil and extracted with methanol. Chemical characterization was performed by spectroscopies ultraviolet, visible and infrared. Anti-inflammatory properties were assessed by in vivo carrageenan-induced mouse paw oedema. Radical scavenging was evaluated by DPPH method. In toxicological evaluation Salmonella/microsome mutagenicity assay, in the presence and absence of exogenous metabolic activation, the in vitro mammalian cell micronucleus test and mortality test to brine shrimp Artemia salina were performed. Distinct chemical groups in extracts were found, with the results being corroborated with the literature. The extracts from both species showed significant inhibition of paw oedema at the doses tested, in relation to the vehicle. Both extracts showed DPPH radicals scavenger capacity. Cytotoxic and mutagenic activities in the absence of exogenous metabolism were not observed for TA97, TA98 and TA102 strains by both species. T. coccinea extract induced cytotoxicity in TA100 at 50 μg/placa. Both extracts induced cytotoxicity in the presence of exogenous metabolism for TA98 strain, and was also detected induction of mutagenicity by T. coccinea extract. The extracts were unable to induce micronucleus formation and were not toxic to the brine shrimp assay. The inhibitory response of carrageenan-induced mouse paw oedema after two hours indicates that the compounds present in the extracts act on the second stage of inflammation, possibly by inhibiting prostaglandin production. The results suggest that the extracts of the species T. coccinea and T. tagusensis contain pharmacological substances with potential use as anti-inflammatory and antioxidant.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / O ambiente marinho é um dos ecossistemas mais diversos e complexos em termos de biodiversidade. As condições químicas, físicas e biológicas desse ambiente favorecem a produção de uma variedade de substâncias pela biota, transformando os produtos naturais marinhos em um dos recursos promissores na pesquisa por novos compostos bioativos. O gênero Tubastraea (Scleractinia, Dendrophylliidae) inclui corais ahermatípicos que produzem compostos secundários bioativos em situações de competição. No estado do Rio de Janeiro são encontradas duas espécies invasoras desse gênero, Tubastraea coccinea e Tubastraea tagusensis. A primeira é amplamente distribuída nas águas tropicais do Atlântico e do Pacífico, e a segunda é nativa do leste do pacífico, ambas invasoras no Atlântico Sul. Este trabalho objetiva avaliar as atividades anti-inflamatória, antioxidante e toxicológica de extratos metanólicos de T. coccinea e T. tagusensis. As colônias de Tubastraea foram coletadas na Baía de Ilha Grande, Rio de Janeiro - Brasil e extraídas com metanol. A caracterização química foi realizada através da espectroscopia ultravioleta, visível e de infravermelho. Ação anti-inflamatória foi avaliada pelo modelo in vivo de edema em pata de camundongo induzido por carragenina. Atividade sequestrante de radicais livres foi avaliada pelo método do DPPH. Na avaliação toxicológica utilizamos o ensaio Salmonella/microssoma, na presença e ausência de ativação metabólica exógena, o teste in vitro de micronúcleo com células de macrófagos de rato e o teste de mortalidade com o microcrustáceo Artemia salina. Foi possível a distinção dos grupos químicos presentes nos extratos, com os resultados encontrados sendo corroborados com os presentes na literatura. Os extratos de ambas as espécies apresentaram inibição significativa no edema da pata nas doses testadas, em relação ao veículo. Ambos os extratos demonstraram capacidade pela captura do radical DPPH. Atividades citotóxica e mutagênica na ausência de metabolização exógena não foram observadas para as linhagens TA97, TA98 e TA102 nas duas espécies; para a TA100 o extrato de T. coccinea induziu citotoxidade na concentração de 50 g/placa. Os dois extratos induziram citotoxicidade na presença de metabolização exógena para a cepa TA98, tendo sido detectada também indução de mutagenicidade nesta linhagem para T. coccinea. Os extratos não foram capazes de induzir a formação de micronúcleos e não foram tóxicos para o microcrustáceo A. salina. A resposta inibitória do edema após 2 h da indução indica que os compostos presentes nos extratos atuam na segunda fase da inflamação, possivelmente pela inibição da produção de prostaglandinas. Os resultados sugerem que os extratos das espécies T. coccinea e T. tagusensis apresentam substâncias com potencial uso farmacológico, como agente anti-inflamatório e antioxidante. / The marine environment is one of the most diverse and complex ecosystems in terms of biodiversity. The conditions of chemical, physical and biological environment enables the production of a variety of substances by the biota, transforming the marine natural products resources on a promising research for new bioactive compounds. The genus Tubastraea (Scleractinia, Dendrophylliidae) includes ahermatypic corals that produce bioactive secondary compounds in competitive situations. In the state of Rio de Janeiro are found two invasive species of this genus, Tubastraea coccinea and Tubastraea tagusensis. The first is widely distributed in the tropical waters of the Atlantic and Pacific, and the second is native to the eastern Pacific, both are invasive in the South Atlantic. This study is focused on the anti-inflammatory, antioxidant and toxicological evaluation of methanol extracts of T. coccinea and T. tagusensis. Tubastraea colonies were collected in the Ilha Grande Bay, Rio de Janeiro - Brazil and extracted with methanol. Chemical characterization was performed by spectroscopies ultraviolet, visible and infrared. Anti-inflammatory properties were assessed by in vivo carrageenan-induced mouse paw oedema. Radical scavenging was evaluated by DPPH method. In toxicological evaluation Salmonella/microsome mutagenicity assay, in the presence and absence of exogenous metabolic activation, the in vitro mammalian cell micronucleus test and mortality test to brine shrimp Artemia salina were performed. Distinct chemical groups in extracts were found, with the results being corroborated with the literature. The extracts from both species showed significant inhibition of paw oedema at the doses tested, in relation to the vehicle. Both extracts showed DPPH radicals scavenger capacity. Cytotoxic and mutagenic activities in the absence of exogenous metabolism were not observed for TA97, TA98 and TA102 strains by both species. T. coccinea extract induced cytotoxicity in TA100 at 50 μg/placa. Both extracts induced cytotoxicity in the presence of exogenous metabolism for TA98 strain, and was also detected induction of mutagenicity by T. coccinea extract. The extracts were unable to induce micronucleus formation and were not toxic to the brine shrimp assay. The inhibitory response of carrageenan-induced mouse paw oedema after two hours indicates that the compounds present in the extracts act on the second stage of inflammation, possibly by inhibiting prostaglandin production. The results suggest that the extracts of the species T. coccinea and T. tagusensis contain pharmacological substances with potential use as anti-inflammatory and antioxidant.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Este trabalho avaliou, inicialmente, a citotoxicidade dos extratos hidroalcoÃlicos das 10 espÃcies de ascÃdias mais abundantes do litoral cearense atravÃs dos seguintes mÃtodos: toxicidade aguda em larvas de artemias, inibiÃÃo do desenvolvimento dos ovos de ouriÃo-do-mar, potencial hemolÃtico e inibiÃÃo da proliferaÃÃo celular de linhagens tumorais. A espÃcie Eudistoma vannamei mostrou-se a mais ativa em 3 dos 4 ensaios performados, sendo, portanto, selecionada para prosseguir com a caracterizaÃÃo quÃmica e farmacolÃgica de seus princÃpios ativos. O extrato foi particionado em diversos solventes e fracionados por cromatografia em sÃlica gel 60 e sephadex LH-20. A atividade das amostras foi monitorada pelo mÃtodo do MTT. Das 60 amostras coletadas, 15 foram ativas. A CI50 dessas 15 amostras foi verificada, novamente pelo mÃtodo do MTT, em 5 linhagens celulares tumorais: CEM, HL-60, MCF-7, HCT-8 e B-16. As fraÃÃes DCM-14 a DCM-18, derivadas da fase diclorometÃnica e quimicamente muito semelhantes entre si, como evidenciado por CCDC, foram as mais ativas, apresentando CI50 de atà 1,0 ug/mL na maioria das linhagens. A dicetopiperazina 6-etilamino-1-metil-piperazina-2,5-diona foi isolada da fase CHCl2 e detectada como o componente majoritÃrio, no entanto, foi inativa sobre a proliferaÃÃo celular. O espectro de H1RNM das fraÃÃes DCM-14 a 18 indicou, como componentes minoritÃrios, uma sÃrie de derivados desta dicetopiperazina, que nÃo foram identificados. O estudo dos efeitos das fraÃÃes sobre a viabilidade (exclusÃo por azul de tripan), proliferaÃÃo (incorporaÃÃo de BrdU e curva de crescimento) e induÃÃo de morte (morfologia celular â coloraÃÃo por H/E â anexina e coloraÃÃo por BE/AO) nas cÃlulas HL-60 demonstrou que DCM-16 e 17 sÃo as mais fortes redutoras da proliferaÃÃo celular. DCM-16 apresentou um pronunciado efeito inibitÃrio sobre a incorporaÃÃo de BrdU, o que pode indicar uma interferÃncia na duplicaÃÃo de DNA. DCM-17 inibiu satisfatoriamente a incorporaÃÃo de BrdU, mas a induÃÃo de apoptose Ã, aparentemente, seu mecanismo predominante. DCM-14 e 15 tambÃm apresentam perfis de indutoras de apoptose celular, sendo que a Ãltima demonstra alguns indÃcios de atividade necrÃtica. Os efeitos de DCM-18 foram pouco pronunciados. As atividades apresentadas por essas fraÃÃes sÃo concentraÃÃo-dependente e o aumento do tempo de contato intensifica o efeito citotÃxico. / The study, initially, evaluated the citotoxity of the hydro-alcoholic extracts of the 10 most abundant ascidian species from the coast of Cearà (Brazil), through the utilization of the following methods: brine shrimps lethality assay; development inhibition of sea urchin eggs; hemolytic potential, and inhibition of in vitro tumor cell growth. In three of the four assays performed, the Eudistoma vannamei species proved to be the most active one, and it was, therefore, selected for chemical and pharmacological characterization of its active principles. The extract was particionated by various solvents and fractionated by chromatography in silica gel 60 and sephadex LH-20 columns. The samplesâ activities were monitored through the MTT method. Of the 60 collected samples, 15 were active. The IC50 of the 15 samples was evaluated through the MTT method, in 5 tumor cell lines: CEM, HL-60, MCF-7, HCT-8 e B-16. The fractions DCM-14 to DCM-18, derived from the CHCl2 phase and chemically very similar to each other, as indicated by CCDC, were the most active ones, presenting IC50 under 1,0 ug/mL in the majority of lines. The diketopiperazine 6-ethylamino-1-methyl-piperazine-2,5-dione was isolated from CHCl2 phase and identified as the major component, however, it was inactive upon cell proliferation. The H1RNM spectra of DCM 14 to DCM 18 fractions showed a number of compounds derived from that major diketopiperazine, which were not identified, as minor components. The study about the fractions effect upon HL-60âs viability (exclusion by trypan blue), proliferation (BrdU incorporation and growth curve) and cell death induction (cell morphology - H/E staining â annexin and BE/AO) revealed DCM-16 and 17 as the most potent cell proliferation reducers. DCM-16 displayed a pronounced BrdU uptake inhibitory effect, which may indicate interference in the DNA duplication process. DCM-17 showed a satisfactorily inhibition upon BrdU uptake, however, the apoptosis induction seems to be its main mode of action. DCM-14 and 15 also displayed a cell apoptosis inductor profile, while the latter indicated some signs of necrotic activity. The activities presented by these fractions are concentration and time dependent as longer periods with cell contact intensifies its citotoxic effect.

Pancreatic cancer is the fourth most lethal cancer and ranks as the eighth most commonly diagnosed cancer worldwide. This is due to its rapid proliferation, strong metastatic potential and its delayed detection. One major risk factor for developing pancreatic cancer is the aggressive inflammatory disease chronic pancreatitis. Chronic inflammation frequently precedes the development of certain pancreatic cancers. Inflammation is a protective and necessary process by which the body can alert the immune system of the existence of a wound or infection and mount an immune response to remove the harmful stimuli and start wound healing. The cross-talking of cells of the immune system and infected cells happens through cytokines, soluble proteins that activate and recruit other immune cells to increase the system’s response to the pathogen. Failure to resolve the injury can result in persistent cytokine production that in turn allows a cell that is damaged or altered to survive when in normal conditions it would be killed. Inflammation is thought to create a microenvironment that facilitates the initiation and/or growth of pancreatic cancer cells. Cytokines use two important kinases for their signaling: Janus Kinases (JAKs) and Signal Transducers and Activators of Transcription (STATs). The JAKs are activated upon the binding of cytokines to their corresponding receptors. When activated, the JAKs activate STATs through tyrosine phosphorylation. The STATs transduce signals to the nucleus of the cells to induce expression of critical genes essential in normal physiological cellular events such as differentiation, proliferation, cell survival, apoptosis and angiogenesis. STAT3 (a member of the STAT family) is constitutively activated in some pancreatic cancers, promoting cell cycle progression, cellular transformations and preventing apoptosis. Therefore, STAT3 is a promising target for cancer treatment. Novel therapies that inhibit STAT3 activity in cancers are urgently needed. Natural products are a very good resource for the discovery of new drugs against pancreatic cancer. Covering more than 70% of the Earths surface, The Ocean is an excellent source of bioactive natural products. Harbor Branch Oceanographic Institute’s Center for Marine Biomedical and Biotechnology Research (HBOI-CMBBR) situated in Florida, aims to find new marine natural products useful in disease prevention and drug therapy. Their current focus is to look for novel treatments for preventing both the formation of new pancreatic tumors and the metastasis of existing tumors. The hypothesis of this degree project was that novel inhibitors of STAT3 useful in the treatment of pancreatitis and/or pancreatic cancer could be found from marine-natural products. The first specific aim of this degree project was to set up an assay to identify bioactive marine natural products as inhibitors of inflammation. Furthermore the assay was validated using a commercially available inhibitor of inflammation (Cucurbitacin I). The last aim was to further validate the assay by screening pure compounds and peak library material from the HBOI marine specimen collection. At the end of the experimentation time, the assay still was not set-up as there were difficulties in proper cell culture techniques and the cell line did not respond as advertised. While the results were not as expected, the work performed resulted in familiarization with research laboratory practices and increased laboratory skills. Moreover, the results from the assays point to future directions to accomplish this project. / Development of a screening assay for inhibitors of inflammation useful against pancreatic cancer

This thesis is an investigation of the natural products deriving from marine algae and cyanobacteria and has resulted in the discovery of eleven new secondary metabolites. The structure elucidations of these new molecules were performed using a variety of spectroscopic techniques. Four new macrolides were isolated and characterized from the Madagascar marine cyanobacterium Geitlerinema sp. These ankaraholides are structurally similar to the potently cytotoxic swinholides and were found to have cytotoxicities ranging from 178 nM to 354 nM against human lung cancer (NCI-H460) and mouse neuro-2a cell lines. Since swinholide-type compounds were previously localized to the heterotrophic bacteria of sponges, these findings raise intriguing questions about their true metabolic source. Geitlerinema sp. was found to be particularly rich in chemistry, and also produced the new linear lipopeptide mitsoamide with unusual structural features including an aminal moiety, a homolysine residue and a polyketide unit (3,7- dimethoxy-5-methyl- nonanedioic acid) (DMNA). A collection of the red marine alga Portieria hornemannii from the south of Madagascar (Tolagniaro, Fort Dauphin), led to the isolation of the previously reported halogenated monoterpene, halomon, and the discovery of three new related metabolites. These molecules were found to inhibit DNA methyltransferase 1 (DNMT-1). As a result of efforts to identify bioactive agents from the marine cyanobacterium Lyngbya majuscula, tanikolide dimer, a novel SIRT2 inhibitor (IC50 = 176 nM), and tanikolide seco-acid were isolated. The depside molecular structure of tanikolide dimer, which is likely a meso compound, was established by NMR, MS and chiral HPLC analyses. The structure of tanikolide dimer raises a number of intriguing configurational and biosynthetic questions for further study. The bioassay guided fractionation of a collection of the brown marine alga Dictyota sp. from Netherland Antilles Playa Fort, led to the identification of a novel HDAC inhibitor with a dolastane carbon skeleton. The novel molecule was also found to possess antimalarial activity. Other known HDAC inhibitors with interesting antimalarial activity have been reported previously, and based on this efficacy against malaria, HDAC appears to be a viable target for the development of antiparasitic agents. / Graduation date: 2006

A diversidade de organismos oriundos do ambiente marinho constitui uma fonte significativa de substâncias estruturalmente inéditas e biologicamente ativas, dentre as quais, diversas inspiraram o desenvolvimento de novas classes de agentes terapêuticos. Neste contexto, macroalgas vermelhas do gênero Bostrychia (Rhodomelaceae) foram coletadas em praias do litoral norte do estado de São Paulo e têm sido objeto de estudos químicos e biológicos, no Laboratório de Química Orgânica do Ambiente Marinho (LQOAM - NPPNS) da FCFRPUSP, sob a supervisão da Profa. Dra. Hosana M. Debonsi. As algas da espécie Bostrychia radicans demonstraram potencial quando avaliadas as atividade citotóxica, tripanocida, leishmanicida e antimicrobiana; além de um perfil químico interessante, evidenciado pelo isolamento de substâncias inéditas na literatura. Neste contexto, o presente trabalho descreve a continuidade do estudo químico da espécie B. radicans, coletada no Manguezal do Rio Escuro, em Ubatuba-SP; bem como o potencial biológico desta espécie, além da avaliação da atividade de enzimas fenolsulfatases na espécie. Ainda, no sentido de explorar novas fontes promissoras para o isolamento de substâncias bioativas, este trabalho descreve o isolamento de micro-organismos endofíticos associados à espécie B. radicans. Foram isoladas 45 linhagens de micro-organismos; dentre as quais foram selecionadas nove linhagens para obtenção de extratos e realização de triagens química e biológica. A partir desta triagem inicial, foi realizado o estudo químico dos fungos Xylaria sp., Penicillium brevicompactum e Phomopsis longicolla. A partir da Xylaria sp. foram isoladas as seguintes substâncias: ácido 2,5-diidroxibenzóico, 8-diidroxinaftol 1-O-a-glucopiranosídeo, 8-metóxi-3-metil-1- isocromanona e ácido pilifórmico. O estudo químico de Penicillium brevicompactum resultou no isolamento das substâncias: ácido micofenólico, asperfenamato, brevianamida A, brevianamida C e brevianamida oxindol, substância inédita como produto natural. A partir de Phomopsis longicolla foi isolado o dicerandrol C. Este trabalho descreve ainda o potencial biológico de algumas destas substâncias isoladas. O estudo químico e biológico de microorganismos realizado no LQOAM estimulou a consolidação de uma colaboração com o Prof. Dr. Isidro C. Gonzalez, através da realização de um estágio de 12 meses no Laboratório Botrytis (Departamento de Química Orgânica, Universidade de Cádiz). Durante este período foi realizado o estudo químico do fitopatógeno Botrytis cinerea, visando o isolamento de novos metabólitos ou toxinas; além do estudo da biogênese destas substâncias, através de ensaios utilizando precursores isotopicamente marcados. / The diversity of organisms from the marine environment is a significant source of structurally novel and biologically active substances, several of which have inspired the development of new classes of therapeutic agents. In this context, red macroalgae belonging to Bostrychia genus (Rhodomelaceae) were collected on beaches of the north coast of São Paulo State and have been studied chemically and biologically in the Laboratory of Organic Chemistry of the Marine Environment - (LQOAM - NPPNS) at FCFRP-USP, under Prof. Hosana M. Debonsi supervision. Algae Bostrychia radicans species showed cytotoxic, trypanocidal, antileishmanial and antimicrobial potential, besides a interesting chemical profile, evidenced by the isolation of new compounds in the literature. In this context, this work describes the sequential chemical study of B. radicans species, collected at the Rio Escuro Mangrove, Ubatuba-SP, as well as the biological potential of this species. Also, the phenolsulphatases enzyme activity was evaluated in this species. Still, in order to explore new promising sources for the isolation of bioactive substances, this study describes the isolation of endophytic microorganisms associated to B. radicans. In this way, 45 strains of microorganisms were isolated and nine strains were selected for extracts preparation; and subsequently chemical and biological screenings. Based on the biological screening and chemical profile analyses, the large-scale fermentation of the endophytic fungi Xylaria sp., Penicillium brevicompactum and Phomopsis longicolla was carried out. The chromatographic purification of the bioactive acethyl acetate extract from Xylaria sp. allowed the isolation of 2,5-dihydroxybenzoic acid, 8- dihydroxynaphtol 1-O-a-glucopyranoside, 8-methoxy-3-methyl-1-isochromanone and piliformic acid. Chemical studies of Penicillium brevicompactum resulted in the isolation of: mycophenolic acid, asperphenamate, brevianamide A, brevianamide C and brevianamide oxindole, isolated for the first time as a natural product. From Phomopsis longicolla was isolated dicerandrol C. This thesis also describes the potential biological of some of these isolated compounds. The chemical and biological studies of microorganisms achieved in LQOAM encouraged the consolidation of a collaboration work with Prof. Dr. Isidro C. Gonzalez, through the completion of a 12-month internship at the Laboratory Botrytis (Department of Organic Chemistry, University of Cádiz). During this period, was conducted the chemical study of plant pathogen Botrytis cinerea, aiming the isolation of new metabolites or toxins, in addition to studying the biogenesis of these substances, through experiments using isotopically labeled precursors.

Metagenomics has revealed that the marine microbial biosphere is immensely more diverse than originally considered, and is an almost untapped reservoir for the potential discovery of microbial natural products. Despite numerous advances in culturing, biosynthetic engineering and genomic-based screening efforts to uncover much of this diversity in relatively accessible environments, a high rediscovery rate has resulted in the investigation of unique, relatively unexplored ecosystems harboring phylogenetically diverse communities of marine organisms. The focus of this research was to establish a culture repository of microorganisms collected from the Red Sea and from deep-sea hydrothermal vents, and to assess their biosynthetic potential for the production of new chemical scaffolds. Cultivation of marine cyanobacteria from the Red Sea has led to the identification of five new cyclic depsipeptides, apratoxin H, grassypeptolides D and E, Ibu-epidemethoxylyngbyastin 3 and leptochelin, the latter possessing a unique chemical scaffold capable of binding metals. A collection of deep-sea hydrothermal vent sediment and microbial mat samples led to the isolation of 64 unique bacterial strains, with eight assigned as members of the order Actinomycetales. Importantly, these isolates, along with a collection of deep-vent invertebrates and microbes, have led to the development of methods for the collection, culturing and biological screening of organisms from this extreme environment for future natural products research. / Graduation date: 2013

The principle theme of this thesis was the synthesis of bioactive compounds. To this end, this work was focus on two main projects. The first one, which was carried out in the Department of Chemistry of the University of Girona under the supervision of Dr Montserrat Heras, concerned the synthesis of new unnatural amino acids bearing a pyrimidine ring within their side chain for incorporation into the antimicrobial peptide BP100 following a rational design in order to improve its biological profile. On the other hand, the second chapter of this thesis was developed in collaboration with the Laboratoire de Chimie Organique (ESPCI-ParisTech, Paris, France) under the guidance of Pr Janine Cossy and Dr Arseniyadis. This chapter was centered on the total synthesis of three marine natural products with complex structures and interesting biological activities: acremolide B, (–) bitungolide F and lyngbouilloside. / Aquesta tesi s'ha centrat en la preparació de nous compostos bioactius seguint dues estratègies diferents. El primer projecte es va portar a terme sota la supervisió de la Dra. Montserrat Heras del grup LIPPSO del Departament de Química i ha permés el desenvolupament de noves metodologies per la síntesi de nous aminoàcids no naturals. i el seu ús en la preparació d'anàlegs del pèptid antimicrobià BP100 amb l'objectiu de millorar-ne les propietats biològiques. El segon projecte és fruit de la col•laboració amb la Prof. Janine Cossy i el Dr. Stellios Arseniyadis del "Laboratoire de Chimie Organique" de l'Ecole Superieur de Physique et Chimie Industrielles (ESPCI-ParisTech, Paris, França). I ha permés posar a punt tres estratègies sintètiques convergents i versàtils per l’obtenció de tres productes naturals de gran complexitat estructural i interessants activitats biològiques – l'acremolide B, la bitungolide F i la lyngbouilloside – aïllats recentment del fons marí de diferents punts del món.

A diversidade de organismos oriundos do ambiente marinho constitui uma fonte significativa de substâncias estruturalmente inéditas e biologicamente ativas, dentre as quais, diversas inspiraram o desenvolvimento de novas classes de agentes terapêuticos. Neste contexto, macroalgas vermelhas do gênero Bostrychia (Rhodomelaceae) foram coletadas em praias do litoral norte do estado de São Paulo e têm sido objeto de estudos químicos e biológicos, no Laboratório de Química Orgânica do Ambiente Marinho (LQOAM - NPPNS) da FCFRPUSP, sob a supervisão da Profa. Dra. Hosana M. Debonsi. As algas da espécie Bostrychia radicans demonstraram potencial quando avaliadas as atividade citotóxica, tripanocida, leishmanicida e antimicrobiana; além de um perfil químico interessante, evidenciado pelo isolamento de substâncias inéditas na literatura. Neste contexto, o presente trabalho descreve a continuidade do estudo químico da espécie B. radicans, coletada no Manguezal do Rio Escuro, em Ubatuba-SP; bem como o potencial biológico desta espécie, além da avaliação da atividade de enzimas fenolsulfatases na espécie. Ainda, no sentido de explorar novas fontes promissoras para o isolamento de substâncias bioativas, este trabalho descreve o isolamento de micro-organismos endofíticos associados à espécie B. radicans. Foram isoladas 45 linhagens de micro-organismos; dentre as quais foram selecionadas nove linhagens para obtenção de extratos e realização de triagens química e biológica. A partir desta triagem inicial, foi realizado o estudo químico dos fungos Xylaria sp., Penicillium brevicompactum e Phomopsis longicolla. A partir da Xylaria sp. foram isoladas as seguintes substâncias: ácido 2,5-diidroxibenzóico, 8-diidroxinaftol 1-O-a-glucopiranosídeo, 8-metóxi-3-metil-1- isocromanona e ácido pilifórmico. O estudo químico de Penicillium brevicompactum resultou no isolamento das substâncias: ácido micofenólico, asperfenamato, brevianamida A, brevianamida C e brevianamida oxindol, substância inédita como produto natural. A partir de Phomopsis longicolla foi isolado o dicerandrol C. Este trabalho descreve ainda o potencial biológico de algumas destas substâncias isoladas. O estudo químico e biológico de microorganismos realizado no LQOAM estimulou a consolidação de uma colaboração com o Prof. Dr. Isidro C. Gonzalez, através da realização de um estágio de 12 meses no Laboratório Botrytis (Departamento de Química Orgânica, Universidade de Cádiz). Durante este período foi realizado o estudo químico do fitopatógeno Botrytis cinerea, visando o isolamento de novos metabólitos ou toxinas; além do estudo da biogênese destas substâncias, através de ensaios utilizando precursores isotopicamente marcados. / The diversity of organisms from the marine environment is a significant source of structurally novel and biologically active substances, several of which have inspired the development of new classes of therapeutic agents. In this context, red macroalgae belonging to Bostrychia genus (Rhodomelaceae) were collected on beaches of the north coast of São Paulo State and have been studied chemically and biologically in the Laboratory of Organic Chemistry of the Marine Environment - (LQOAM - NPPNS) at FCFRP-USP, under Prof. Hosana M. Debonsi supervision. Algae Bostrychia radicans species showed cytotoxic, trypanocidal, antileishmanial and antimicrobial potential, besides a interesting chemical profile, evidenced by the isolation of new compounds in the literature. In this context, this work describes the sequential chemical study of B. radicans species, collected at the Rio Escuro Mangrove, Ubatuba-SP, as well as the biological potential of this species. Also, the phenolsulphatases enzyme activity was evaluated in this species. Still, in order to explore new promising sources for the isolation of bioactive substances, this study describes the isolation of endophytic microorganisms associated to B. radicans. In this way, 45 strains of microorganisms were isolated and nine strains were selected for extracts preparation; and subsequently chemical and biological screenings. Based on the biological screening and chemical profile analyses, the large-scale fermentation of the endophytic fungi Xylaria sp., Penicillium brevicompactum and Phomopsis longicolla was carried out. The chromatographic purification of the bioactive acethyl acetate extract from Xylaria sp. allowed the isolation of 2,5-dihydroxybenzoic acid, 8- dihydroxynaphtol 1-O-a-glucopyranoside, 8-methoxy-3-methyl-1-isochromanone and piliformic acid. Chemical studies of Penicillium brevicompactum resulted in the isolation of: mycophenolic acid, asperphenamate, brevianamide A, brevianamide C and brevianamide oxindole, isolated for the first time as a natural product. From Phomopsis longicolla was isolated dicerandrol C. This thesis also describes the potential biological of some of these isolated compounds. The chemical and biological studies of microorganisms achieved in LQOAM encouraged the consolidation of a collaboration work with Prof. Dr. Isidro C. Gonzalez, through the completion of a 12-month internship at the Laboratory Botrytis (Department of Organic Chemistry, University of Cádiz). During this period, was conducted the chemical study of plant pathogen Botrytis cinerea, aiming the isolation of new metabolites or toxins, in addition to studying the biogenesis of these substances, through experiments using isotopically labeled precursors.

O presente projeto de pesquisa teve por objetivo a descoberta de metabólitos secundários potencialmente bioativos contra atividade parasitária e como agentes anti-virais e antibióticos, usando desreplicação como metodologia essencial na seleção e priorização de extratos brutos oriundos de invertebrados, para a descoberta de produtos naturais estruturalmente inéditos.<br /><br />Foram preparados diversos extratos de invertebrados marinhos a partir de um fracionamento inicial. O desenvolvimento e a aplicação de uma metodologia de desreplicação permitiu a seleção de três organismos de estudo, Iotrochota birotulata, Amathia verticillata, e Tedania brasiliensis. Os extratos destes organismos foram submetidos a diferentes metodologias de fracionamento, isolamento e purificação de substâncias, dependendo dos resultados de desreplicação para cada organismo.<br /><br />Como resultado do isolamento e identificação de substancias destes organismos, obteve-se dois compostos já conhecidos na literatura e dezesseis compostos inéditos, dos quais dois são derivados sintéticos. De todos os compostos isolados, a pseudoceratidina, as desbromopseudoceratidinas e as tedamidas A e B apresentaram um índice de seletividade de 243.1, 217.1 e 89.3 respectivamente para Leishmania (L.) infantum, e o composto N12-acetilpseudoceratidina de 23.2 para Trypanosoma cruzi, sendo estes resultados muito promissores para a utilização das estruturas destas moléculas como potenciais modelos para o desenvolvimento de fármacos. / This research project aimed at the discovery of potentially bioactive secondary metabolites against parasitic activity and as antiviral agents and antibiotics, using dereplication as an essential methodology in the selection and prioritization of crude extracts derived from invertebrates, to the discovery of natural products structurally unpublished.<br /><br />Various extracts of marine invertebrates from an initial fractionation were prepared. The development and application of a dereplication methodology allowed the selection of three study organisms, Iotrochota birotulata, Amathia verticillata, and Tedania brasiliensis. The extracts of these organisms were subjected to different methods of fractionation, isolation and purification of substances, depending on the results of dereplication for each organism.<br /><br /> As a result of the isolation and identification of substances of these organisms, it obtained two compounds already known in the literature and unpublished sixteen compounds, two of which are synthetic derivatives. In all isolated compounds, pseudoceratidina, the desbromopseudoceratidinas and tedamidas A and B showed an index of selectivity 243.1, 217.1 and 89.3 respectively for Leishmania (L.) infantum, and the compound N12-acetilpseudoceratidina 23.2 for Trypanosoma cruzi, which are very promising results for the use of these molecules as structures potential models for drug development.