An extract of the sponge <i>Rhabdastrella globostellifera</i> was active in an assay measuring stabilization of the binding of DNA with DNA polymerase β. From this extract, four isomalabaricane triterpenoids were isolated and characterized, three of which were active in the binding assay. All compounds were active in the A2780 ovarian cancer cell line assay. Bioassay-guided fractionation of an extract of a sponge of species <i>Dysidea</i> using the A2780 bioassay yielded the known scalarane sesterterpenoid heteronemin in good yield. Four derivatives of heteronemin were prepared semisynthetically from the natural product, tested for their bioactivity, and their structure-activity dependence was observed. Bioassay guided-fractionation of an extract of a <i>Tuemoya</i> sp. green alga, using an assay for inhibitors of the enzyme Tie2 kinase, afforded a two sulfated cycloartanol triterpenoids. Both the major and minor compounds were identified by spectroscopic methods. Bioassay-guided fractionation of an extract of <i>Petalonyx parryi</i> yielded three known oleanane triterpenoids which inhibited the lyase domain of DNA polymerase β. The structures were confirmed by NMR spectroscopic techniques. This is the first reported study of the chemical components of <i>Petalonyx parryi</i>. As part of our antitumor natural product drug discovery efforts, several extracts were selected for bioassay-guided fractionation based on their activity in initial in vitro screens. A new dereplication method using aminopropyl SPE cartridges was applied to six of these extracts, and four of the extracts were dropped due to the presence of long-chain fatty acids (LCFAs). We present results for the testing and application of this SPE-based method for LCFA dereplication. The cell cycle kinase Chk1 is an interesting target for the development of agents which might potentiate DNA damaging agents. Typical assays for Chk1 involve the use of expensive or radioactive reagents. To facilitate the development of new assays using shorter peptide substrates, small libraries of peptides have been synthesized and tested for their activity as Chk1 substrates. Several of the substrates synthesized displayed activity in the Chk1 assay. / Ph. D.

Antibiotics form the cornerstone of modern medicine, facilitating advancements in numerous healthcare fields and contributing to unprecedented increases in human life expectancy. However, the efficacy of these life-saving drugs is now jeopardized by the rise of antimicrobial resistance. This growing threat is exacerbated by the slow pace of new antibiotic discoveries. The drug discovery process is both time-consuming and costly, and efforts to identify novel antibiotics often result in the rediscovery of known antibiotics, further hindering progress. To combat antibiotic resistance and facilitate the discovery of novel drugs, several approaches can be employed. First, understanding the mechanisms of resistance found in environmental bacteria is crucial for preparing against the potential mobilization of these resistance mechanisms into pathogenic bacteria. Second, developing tools that make the drug discovery process less costly and time-consuming can accelerate the discovery rate and broaden participation in drug discovery efforts. Finally, understanding how bacteria synthesize natural product antibiotics provides invaluable information that can be leveraged in drug discovery efforts, including synthetic biology approaches. This thesis addresses efforts and challenges in the various aspects of drug discovery. To enhance our understanding of environmental resistance mechanisms, I conducted a screen for ciprofloxacin-inactivating enzymes and characterized the activity of a previously reported ciprofloxacin-inactivating enzyme, CrpP. These findings highlight the difficulties associated with discovering synthetic antibiotic-inactivating enzymes. To contribute to drug discovery, I expanded the Antibiotic Resistance Platform and developed a streamlined version to improve antibiotic dereplication efforts, thereby accelerating the natural product discovery process. Additionally, I investigated the mechanism of β-serine biosynthesis, a nonproteinogenic amino acid found in the antibiotic edeine. By elucidating how β-serine is synthesized, this information can be applied to synthetic biology approaches for drug discovery. / Thesis / Doctor of Philosophy (PhD) / Antibiotics used in medical treatments today often originate from natural sources like environmental bacteria and are known as natural product antibiotics. These natural product antibiotics are essential for treating bacterial infections and play a crucial role in modern medicine, including surgery and cancer treatment. However, the increasing problem of antimicrobial resistance and the lack of new drugs being discovered threatens the effectiveness of these life-saving medicines. To combat antibiotic resistance and protect the use of antibiotics, we need to understand how bacteria resist antibiotics, develop better methods for discovering new antibiotics, and gain insights into how bacteria produce natural product antibiotics. This thesis addresses these challenges by trying to find bacteria that can break down antibiotics, improving a tool for drug discovery, and understanding how bacteria make the antibiotic known as edeine. These efforts advance our understanding of antibiotic resistance and pave the way for developing new and effective antibiotics.

Resumo: Neste trabalho foi desenvolvida uma metodologia de desreplicação bioguiada para Qualea grandiflora e Q. cordata, duas espécies da família Vochysiaceae presentes no Cerrado Brasileiro com potencial etnofarmacológico, através dos bioensaios in vitro de inibição da polimerização da β-hematina bovina (compostos antimaláricos), redução do radical estável DPPH (antioxidante), bioautografia para avaliação da inibição da enzima acetilcolinesterase, avaliação citotóxica em linhagens celulares, avaliação de atividade antifúngica por microdiluição em placa e avaliação tripanocida frente à cepas Y de epimastigotas de Tripanosoma cruzi e, da detecção in silico dos constituintes moleculares majoritários a partir da técnica hifenada de HPLC-DAD-HRMS(ESI). As folhas e os ramos secos de Q.grandiflora e Q.cordata foram extraídos por maceração com etanol:água (8:2) e posteriormente fracionados em extração líquido-líquido com os solventes hexano, AcOEt e n-butanol. Entre os bioensaios realizados, a avaliação de inibição do radical DPPH apresentou valores significativos para as frações AcOEt dos ramos de Q.grandiflora e das folhas de Q. cordata. A partir disto, estas frações foram analisadas através da técnica hifenada HPLC-DAD-HRMS(ESI) e permitiram a detecção das flavanonas: 4',5,7-triidroxi-3'-metoxi-6,8-dimetilflavanona e 5,6,7-triidroxi-3',4'-dimetoxi-8-metilflavanona e dos diidroflavonóis: 4',7-diidroxi-5-metoxi-6-metildiidroflavonol e 3',4'-dimetoxi-5,7-diidroxi-6,8-dimetildiidroflavonol na fração AcOEt nas folhas de Q.cordata, e das flavanonas: 8-metilnaringenina e 4',5,7-triidroxi-3',6-dimetoxi-8-metilflavanona; benzofenona: Bis(2-hidroxi-4,6-dimetoxi-3-metilfenil)metanona e diidroflavonol: 3',4',5,6,7-pentaidroxi-8-metildiidroflavonol da fração AcOEt dos ramos de Q.grandiflora. Também realizou-se a análise in silico por RMN da fração... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In this work the bioguided phytochemical studies of Qualea grandiflora and Q. cordata, two species of Vochysiaceae greatly represented in the Brazilian Cerrado and with ethnopharmacology potential, were perfomed according to in vitro bioassays from antioxidant capacity and inhibition of ß-hematin polymerization (antimalarial compounds), scavenging activity of DPPH (antioxidant capacity), inhibition of acetyl cholinesterase (anti-Alzheimer), citotoxic activity against tumoral cell lines (anticancer), antifungal activity using a microdilution assay and tripanocidal activity performed with the Y-strain epimastigote forms of Tripanosoma cruzi, as well as in silico dereplication by means of HPLC-DAD-HRMS(ESI). The leaves and stem of Q.grandiflora and Q.cordata were extracted by maceration in etanol:water (8:2) and fractionated by liquid-liquid using hexane, AcOEt and n-butanol. The bioassays showed that AcOEt stem fraction of Q.grandiflora and AcOEt leaves fraction of Q. cordata are significantly activity in DPPH reduction. According to this results, the AcOEt fraction of the stem of Q.grandiflora and the leaves of Q.cordata were evaluated using HPLC-DAD-HRMS(ESI) and allowed the detection of two flavanones: 4',5,7-trihydroxy-3-methoxy-6,8-dimethylflavanone and 5,6,7-trihydroxy-3',4'-dimethoxy-8-methylflavanone, and the dihydroflavonols: 4',7-dihydroxy-5-methoxy-6-methyldihydroflavonol and 3',4'-dimethoxy-5,7-dihydroxy-6,8-dimethyldihydroflavonol from AcOEt leaves fraction of Q.cordata, and the flavanones: 8-methyl-naringenine and 4',5,7-trihydroxy-3',6-dimethoxy-8-methylflavanone, the benzophenone: bis (2-hydroxy-4,6-dimethoxy-3-methylphenyl) metanone, and the dihydroflavonol: 3',4',5,6,7-pentahydroxy-8-methyldihydroflavonol from AcOEt stem fraction of Q. grandiflora. The AcOEt stem fraction of Q. grandiflora was analyzed through in silico NMR, comparing virtual 1H NMR standards spectra... (Complete abstract click electronic access below) / Orientador: Ian Castro-Gamboa / Coorientador: Márcia Nasser Lopes / Banca: Leonardo Gobbo Neto / Banca: Maique Weber Biavatti / Mestre

Submitted by NATÁLIA CAROLINA VIEIRA null (vieira_naty@hotmail.com) on 2016-03-21T18:33:32Z No. of bitstreams: 1 Dissertação de Mestrado - Natália Carolina Vieira.pdf: 4489683 bytes, checksum: bb278e0db97defa0e9b2982e4b2a0703 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-03-22T18:08:55Z (GMT) No. of bitstreams: 1 vieira_nc_me_araiq.pdf: 4489683 bytes, checksum: bb278e0db97defa0e9b2982e4b2a0703 (MD5) / Made available in DSpace on 2016-03-22T18:08:55Z (GMT). No. of bitstreams: 1 vieira_nc_me_araiq.pdf: 4489683 bytes, checksum: bb278e0db97defa0e9b2982e4b2a0703 (MD5) Previous issue date: 2016-03-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A cada ano vem crescendo a busca por novas fontes de produtos naturais, na qual os micro-organismos recebem uma grande atenção, sendo eles de extrema importância na descoberta de compostos bioativos e promissores a novos fármacos. Esse trabalho teve como foco o estudo de fungos filamentosos da rizosfera de Senna spectabilis. Foram testadas suas viabilidades e após esse processo, dez fungos foram escolhidos para esse trabalho e submetidos aos testes biológicos como citotóxico, anticolinesterásico e antifúngico e também foram obtidos seus perfis cromatográficos e químicos por CLAE-DAD e RMN, além da identificação filogenética. Após esses resultados iniciais, dois fungos foram escolhidos para desenvolver o método de desreplicação, sendo eles Fusarium solani e F. oxysporum. Esses fungos apresentaram atividade antifúngica contra C. cladosporioides e C. sphaerospermun e também apresentaram atividade anticolinesterásica, além disso, F. oxysporum apresentou também atividade antitumoral contra câncer do colorretal. Através das técnicas CG-EM, CLAE-EM, CLAE-EM/EM e RMN foram propostas estruturas moleculares interessantes para substâncias produzidas por esses micro-organismos, sendo que para o extrato de Fusarium solani foram identificados 12 metabólitos: ácido fumárico, ácido málico, tirosol, ácido p-hidroxibenzóico, ácido azelaico, ácido fusárico, (-)-ácido jasmônico/ácido (+)-7-iso-jasmônico, 10-hidroxicaptotecina, C-16-esfinganina, xestoaminol C, armilarina/armilaripina e beauvericina e para o extrato do fungo Fusarium oxysporum foram observados 14 metabólitos: ácido succínico, ácido phidroxibenzóico, ácido hexadecanóico, ácido octadecanóico, ácido fusárico e três de seus derivados, integracídeo C, fusagerina C/D, C-16-esfinganina, xextoaminol C, armilarina/armilaripina e beauvericina. Além desses compostos, outros 5 metabólitos comuns às espécies solani e oxysporum foram observados, mas não puderam ser estruturalmente caracterizados por CLAE-EM/EM, no entanto, suas massas moleculares já foram relatadas para espécies de Fusarium. / The search for new sources of natural products has been increasing to the rational exploration of microorganisms as great sources for the discovery of bioactives and promising compounds as well as new drugs. This work focused on the study of filamentous fungi, isolated from Senna spectabilis’s rhizosphere from which were tested its viabilities. Thereon, ten fungi were chosen for this work and were submitted to biological tests, such as cytotoxic, anticholinesterase and antifungal. In addition, their chemical profiles were obtained for HPLC and NMR, besides phylogenetic identification. Finally, two fungi were chosen to develop dereplication method, being them Fusarium solani and F. oxysporum.These fungi howed anticholinesterase activity and antifungal activity against C. cladosporioides and C. sphaerospermun. Additionally, F. oxysporum showed antitumor activity against colorectal cancer. Through the GC-MS, HPLC-MS, HPLC-MS/MS and NMR, we were able to obtained interesting molecular chemotypes for these microorganisms; for F. solani we identified 12 metabolites, fumaric acid, malic acid, tyrosol, p-hydroxybenzoic acid, azelaic acid, fusaric acid, (+)-7-iso-jasmonic acid/(-)-jasmonic acid, 10- hydroxycamptotecin, C16-sphinganine, xestoaminol C, armillarin/armillaripin and beauvericin and for F. oxysporum was observed 14 metabolites, succinic acid, phydroxybenzoic acid, hexadecanoic acid, octadecanoic acid, fusaric acid and its three derivatives, integracide C, fusagerin C/D, C-16-sphinganine, xestoaminol C, armillarin/armillaripin and beauvericin. Besides these compounds, others 5 metabolites common to both species (solani and oxysporum) couldn’t be structurally characterized thorough LC-MS/MS, but they were accounted in several Fusarium species.

Made available in DSpace on 2014-06-11T19:29:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-20Bitstream added on 2014-06-13T20:59:17Z : No. of bitstreams: 1 carnevaleneto_f_me_araiq.pdf: 2909237 bytes, checksum: d5dbb04db98f4d6c5f87cfc6ae4bfcca (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho foi desenvolvida uma metodologia de desreplicação bioguiada para Qualea grandiflora e Q. cordata, duas espécies da família Vochysiaceae presentes no Cerrado Brasileiro com potencial etnofarmacológico, através dos bioensaios in vitro de inibição da polimerização da β-hematina bovina (compostos antimaláricos), redução do radical estável DPPH (antioxidante), bioautografia para avaliação da inibição da enzima acetilcolinesterase, avaliação citotóxica em linhagens celulares, avaliação de atividade antifúngica por microdiluição em placa e avaliação tripanocida frente à cepas Y de epimastigotas de Tripanosoma cruzi e, da detecção in silico dos constituintes moleculares majoritários a partir da técnica hifenada de HPLC-DAD-HRMS(ESI). As folhas e os ramos secos de Q.grandiflora e Q.cordata foram extraídos por maceração com etanol:água (8:2) e posteriormente fracionados em extração líquido-líquido com os solventes hexano, AcOEt e n-butanol. Entre os bioensaios realizados, a avaliação de inibição do radical DPPH apresentou valores significativos para as frações AcOEt dos ramos de Q.grandiflora e das folhas de Q. cordata. A partir disto, estas frações foram analisadas através da técnica hifenada HPLC-DAD-HRMS(ESI) e permitiram a detecção das flavanonas: 4',5,7-triidroxi-3'-metoxi-6,8-dimetilflavanona e 5,6,7-triidroxi-3',4'-dimetoxi-8-metilflavanona e dos diidroflavonóis: 4',7-diidroxi-5-metoxi-6-metildiidroflavonol e 3',4'-dimetoxi-5,7-diidroxi-6,8-dimetildiidroflavonol na fração AcOEt nas folhas de Q.cordata, e das flavanonas: 8-metilnaringenina e 4',5,7-triidroxi-3',6-dimetoxi-8-metilflavanona; benzofenona: Bis(2-hidroxi-4,6-dimetoxi-3-metilfenil)metanona e diidroflavonol: 3',4',5,6,7-pentaidroxi-8-metildiidroflavonol da fração AcOEt dos ramos de Q.grandiflora. Também realizou-se a análise in silico por RMN da fração... / In this work the bioguided phytochemical studies of Qualea grandiflora and Q. cordata, two species of Vochysiaceae greatly represented in the Brazilian Cerrado and with ethnopharmacology potential, were perfomed according to in vitro bioassays from antioxidant capacity and inhibition of ß-hematin polymerization (antimalarial compounds), scavenging activity of DPPH (antioxidant capacity), inhibition of acetyl cholinesterase (anti-Alzheimer), citotoxic activity against tumoral cell lines (anticancer), antifungal activity using a microdilution assay and tripanocidal activity performed with the Y-strain epimastigote forms of Tripanosoma cruzi, as well as in silico dereplication by means of HPLC-DAD-HRMS(ESI). The leaves and stem of Q.grandiflora and Q.cordata were extracted by maceration in etanol:water (8:2) and fractionated by liquid-liquid using hexane, AcOEt and n-butanol. The bioassays showed that AcOEt stem fraction of Q.grandiflora and AcOEt leaves fraction of Q. cordata are significantly activity in DPPH reduction. According to this results, the AcOEt fraction of the stem of Q.grandiflora and the leaves of Q.cordata were evaluated using HPLC-DAD-HRMS(ESI) and allowed the detection of two flavanones: 4',5,7-trihydroxy-3-methoxy-6,8-dimethylflavanone and 5,6,7-trihydroxy-3',4'-dimethoxy-8-methylflavanone, and the dihydroflavonols: 4',7-dihydroxy-5-methoxy-6-methyldihydroflavonol and 3',4'-dimethoxy-5,7-dihydroxy-6,8-dimethyldihydroflavonol from AcOEt leaves fraction of Q.cordata, and the flavanones: 8-methyl-naringenine and 4',5,7-trihydroxy-3',6-dimethoxy-8-methylflavanone, the benzophenone: bis (2-hydroxy-4,6-dimethoxy-3-methylphenyl) metanone, and the dihydroflavonol: 3',4',5,6,7-pentahydroxy-8-methyldihydroflavonol from AcOEt stem fraction of Q. grandiflora. The AcOEt stem fraction of Q. grandiflora was analyzed through in silico NMR, comparing virtual 1H NMR standards spectra... (Complete abstract click electronic access below)

Actinomycetes and fungi were successfully isolated from both New Zealand and Malaysian marine invertebrates and classified as facultatively marine based on their ability to grow on both sea water and non-sea water media. Most of the extracts obtained from selected isolates were cytotoxic. A clear preference of the actinomycetes for solid-state fermentation was observed, however, for fungi no significant preference was seen. Three isolates of Streptomyces spp., four Penicillium spp. and two Paecilomyces spp. whose extracts showed good cytotoxicity were selected for further investigation. A small-scale extract obtained from a solid culture of Streptomyces sp. (LA3L2) showed good cytotoxicity and a new cytotoxic metabolite was isolated from a large-scale extract of Streptomyces sp. (LA3L2). This metabolite was characterized as S-methyl 2,4-dihydroxy-6-isopropyl-3,5-dimethylbenzothioate (5.15) and is only the third compound reported to contain the S-methyl benzothioate group. Two known compounds, montagnetol (5.16) and erythrin (5.18), were isolated from a further large-scale cultivation of Streptomyces sp. (LA3L2) and is the first reported actinomycete to produce these lichen-related compounds. In addition, two known inactive metabolites (bohemamine (5.1) and bohemamine B (5.2)) were identified from the small-scale extract. Streptomyces sp. (LA3L2) was also investigated for the effect of temperature and salinity on growth and cytotoxicity and shown to produce bohemamine only at 20 - 28℃ and 4% sea salt concentration on solid media. This isolate gave a low yield of active metabolite under all conditions. Small-scale extracts of two other Streptomyces spp. yielded three known cytotoxic metabolites. These were thiazostatin B (7.14) from Streptomyces sp. (LA5L4) and chromomycin A2 (7.1), chromomycin A3 (7.2) and chromomycin 02-3D (7.3) from Streptomyces sp. (LA3L1). All four Penicillium spp. produced known metabolites. Penicillium sp. (LY1L5) yielded two known metabolites, cycloaspeptide A (7.4) and α-cyclopiazonic acid (7.5). α-Cyclopiazonic acid (7.5) and three other known metabolites (roquefortine A (7.6), cyclopeptin (7.7) and viridicatin (7.8)) were isolated from Penicillum sp. (KK3T23). Penicillium sp. (KK3T8) produced brefeldin A (7.10), while mycophenolic acid (7.12) and brevianamide A (7.11) were produced by Penicillium sp. (KK4T14b). The effect of salinity on growth and cytotoxicity was investigated for the two Penicillium isolates producing the cytotoxic metabolite, α-cyclopiazonic acid (7.5). Saline conditions were not required for growth but metabolite production differed between the two isolates with respect to salinity. Isolate LY1L5 required saline conditions for α-cyclopiazonic production whereas isolate KK3T23 produced the metabolite under non-saline conditions and in concentrations of sea salt up to 6%. Three known compounds, indole-3-carboxylic acid (7.15), indole-3-carboxylate (7.17) and 5-carboxymellein (7.16) were identified from Paecilomyces sp. (PR5L9). Investigation of a small-scale extract obtained from a solid culture of another Paecilomyces sp. (PR10T2) resulted in the isolation and characterization of a unique structure of a symmetrical cyclic depsipeptide, epi-angolide (NAM 6-1). NAM 6-1 was considered as a new compound based on four homoisomeric configurations (A1, A2, A3 and A4). The value of dereplication procedures with respect to the rapid identification of metabolites and enhancement of in-house metabolite libraries is discussed. Structural elucidation of nine known metabolites (7.1, 7.2, 7.3, 7.5, 7.6, 7.7, 7.8, 7.10 and 7.11) was greatly aided by the in-house dereplication techniques using LC-MS-UV and AntiMarin database. A significant advantage was gained by the use of the CapNMR which enabled NMR characterization of very small quantities of metabolites (<20 µg). Approximately <5 µg of materials were required to perform 1D proton NMR experiments for the dereplication of seven known compounds; bohemamine (5.1), bohemamine B (5.2), thiazostatin B (7.14), indole-3-carboxylate (7.17) and 5-carboxymellein (7.16). Approximately 20 µg of materials were needed to acquire 1D and 2D (HSQC, HMBC and NOE) NMR spectra for structural elucidation of the new metabolite, S-methyl 2,4-dihydroxy-6-isopropyl-3,5-dimethylbenzothioate (5.15). Some 8 µg of materials were sufficient to perform 1D and 2D (COSY, HSQC and HMBC) NMR experiments for complete structural characterization of two known metabolites, montagnetol (5.16) and erythrin (5.18). Approximately 10 µg of materials were needed to acquire 1D and 2D NMR (COSY, HSQC and HMBC) experiments for structural elucidation of the new compound, epi-angolide NAM 6-1 (A1, A2, A3 and A4). Rapid identification of known fungal metabolites enabled the in-house HPLC-UV/Rt library to be enhanced by eight metabolites (7.5, 7.6, 7.7, 7.8, 7.10, 7.11, 7.17 and 7.16). An HPLC-UV/Rt library for actinomycete metabolites was successfully established with the insertion of eight known metabolites (5.1, 5.2, 5.16, 5.18, 7.1, 7.2, 7.3 and 7.14).

Esponjas do gênero Aplysina (Ordem: VERONGIDA) são conhecidas por apresentarem em seu metabolismo secundário compostos derivados da dibromotirosina, os quais são um importante aliado para o processo de identificação dessas esponjas. Este trabalho descreve o estudo do perfil químico de 14 espécimens de esponjas do gênero Aplysina, coletadas na Bahia de Todos os Santos-BA, no ano de 2007. Também foi desenvolvida uma metodologia de desreplicação, utilizando-se da técnica hifenada HPLC-PDA-MS(ESI), busca na literatura (MarinLit) e comparação com padrões. Os resultados obtidos demonstram claramente que essas esponjas apresentam os derivados da dibromotirosina e que a metodologia de desreplicação permitiu confirmar e/ou prever possíveis estruturas desses compostos com eficiência e sem a necessidade do seu isolamento. Entretanto, não foi possível distinguir as espécies dos organismos estudados através do seu perfil químico, uma vez que eles apresentaram praticamente os mesmos metabólitos em todas as frações analisadas. Isto demonstra que a classificação taxonômica em nível de espécie requer, necessariamente, a análise do esqueleto (espículas) das esponjas e possivelmente análises genômicas. A análise das frações aquosas permitiu apenas confirmar a presença desses derivados através da análise das absorções típicas no espectro de UV. Também, este é o primeiro trabalho sobre o estudo do perfil químico dessas esponjas com a utilização de um sistema de desreplicação que inclui a técnica hifenada HPLC-PDA-MS(ESI). / Sponges of the genus Aplysina (Order: VERONGIDA) are commonly recognized by the presence of dibromotyrisine derivates at their secondary metabolites, compounds which are an important tool for their taxonomic identification. The present study describes the chemical profile of 14 sponges of Aplysina sp., collected in Bahia de Todos os Santos-BA. We developed a dereplication methodology using the hyphenated technique HPLC-PDA-MS(ESI), a database research (MarinLit) and comparison with chemical standards. The results showed that the 14 sponges analysed present dibromotyrisine derivates and that the dereplication methodology enabled the prediction and/or confirmation of such structures without their previous isolation. However, the taxonomic identification of the 14 individual sponges at the species level was impossible due to the fact that chemical profile was of the sponges too similar. This result demonstrates that the taxonomic identification Aplysina sponges at the species level also requires the skeleton analysis and possibly genomic studies. Analyses of aqueous fraction confirmed the presence of dibromotyrisine derivates. Furthermore, this is the first study of the chemical profile of Aplysina sponges that utilizes a dereplication methodology which includes the hyphenated technique HPLC-PDA-MS(ESI).

O objetivo deste trabalho é isolar e identificar os compostos que apresentem atividade fitotóxica presente nos extratos produzidos por actinobactérias isoladas da rizosfera do milho. Para isso foram realizados estudos de derreplicação, baseados nas informações estruturais obtidas por diversas técnicas analíticas. Em especial foi aplicada a espectrometria de massas acoplada a técnicas de purificação, como HPLC e UPLC, com a finalidade de acelerar as análises dos estudos de caracterização estrutural. Com os resultados obtidos foi possível concluir que os extratos oriundos de processos fermentativos apresentam potencial aplicação herbicida, uma vez que mais de 60% das amostras ensaiadas apresentaram atividade fitotóxica. Além disso, foi possível identificar nestes extratos vários compostos com atividades biológicas e estruturas diversas, já descritos na literatura. No extrato da actinobactéria 36 (50 PL) foram encontradas as leucinostatinas que apresentam diversas atividades biológicas como antiviral e antitumoral, além da atividade fitotóxica. Já no extrato da actinobactéria 17 (39 PL) foram encontradas as julicromas, descritas como pigmentos intensos e em geral amarelos, com atividade antibiótica, porém não apresentaram atividade fitotóxica. O composto ativo presente neste extrato pertence à classe das luminacinas, que inibem a formação de tubos capilares, interrompendo o ciclo celular, podendo ser utilizada no tratamento de angiogêneses. A luminacina C, composta por dois epímeros (C1 e C2), apresentou excelente atividade fitotóxica que foi verificada nos bioensaios de fitotoxicidade realizados com Lemna minnor. / Microorganisms, in particular actinomycetes are known to produce a vast number of bioactive secondary metabolites of interesting pharmaceuticals and agrochemical industry. Bioherbicides, especially the micoherbicides, which are highly effective on weed control and are environmentally friendly as well, are very attractive for research and application. This means that direct metabolite profiling techniques such as direct injection mass spectrometry or LC-MS/MS can easily be used for chemotyping/metabolomics of strains from culture collections. In this report we discuss metabolomics as part of intelligent screening for the discovery of phytotoxic compounds when used in combination with modern methods for dereplication. As result, two microorganisms were studied and 23 metabolite peaks were identified. The metabolite profiling was then conducted using the m/z value, and MS/MS fragmentation pattern analyses. Among the peaks, one unknown compound peak was identified and it was analogous to the Luminacins series. In order to render this approach in a more rapid and efficient way, the dereplication of crude microbial extracts with LC-hyphenated techniques (LC/UV-DAD and LC/MS) represented a strategic element to avoid finding known constituents and to target the isolation of new bioactive compounds. The development of simple and rapid phytotoxic bioassays which employed Lemna minor was also crucial to find the active principles efficiently.

Made available in DSpace on 2015-04-22T22:02:11Z (GMT). No. of bitstreams: 1 Felipe_M_A_Silva.pdf: 3616233 bytes, checksum: ce467adbd10803245e8d0c5fdf015ab2 (MD5) Previous issue date: 2011-12-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The neotropical genus Unonopsis, one among the 130 genera belonging to the Annonaceae family, has been a promising source of aporphine alkaloids and derivatives. The antiprotozoal activity of this class of substances, mainly anti-leishmania activity, has aroused the interest of several research groups around the world. In the present work were carried out the analysis from alkaloidal fractions of the leaves, twigs and barks of the trunk from Unonopsis duckei and Unonopsis guatterioides by mass spectrometry, doing an investigation in the alkaloid profile in order to obtain promising structures with activity against Leishmania. The analysis of MSn and LC/APCI/MS of the alkaloidal fractions of U. guatterioides confirmed the presence of some alkaloids previously reported in the literature such as anonaine, asimilobine, liriodenine and lysicamine. It was possible identify the nornuciferine alkaloid which was characterized for the first time in the Unonopsis genus, and suggest the presence of azafluorenone type alkaloid. The spectrometric investigation of U. duckei revealed the presence of aporphine and oxoaporphine alkaloids which were already reported in this genus, as well as guided the isolation of the proaporphine alkaloid glaziovine and the mixture of glaucine and norglaucine alkaloids. These compounds are inedit in the Unonopsis genus. The triterpene polycarpol was isolated from both species, observed U. duckei like the best yield. In the phytochemical investigation of the apolar extracts of U. guatterioides was possible to identify a mixture of sitosterol/stigmasterol steroids. The biological analyses of U. duckei and U. guatterioides alkaloidal fractions showed that four of them were considered highly active, one of them was moderatly active and only one was not showed active against Leishmania amazonensis. Among the substances evaluated, the alkaloid glaziovine showed the most effective activity against Leishmania amazonensis. / O gênero neotropical Unonopsis, um dos 130 gêneros pertencentes à família Annonaceae, tem se mostrado uma fonte promissora de alcalóides aporfínicos e derivados. A atividade antiprotozoário desta classe de substâncias, principalmente a atividade antileishmania, tem despertado o interesse de diversos grupos de pesquisa ao redor do mundo. No presente trabalho foram realizadas as análises das frações alcaloídicas das folhas, galhos e cascas do tronco de Unonopsis duckei e Unonopsis guatterioides por meio de espectrometria de massas, investigando seu perfil alcaloídico com vistas à obtenção de estruturas promissoras em atividade antileishmania. Através das análises de MSn e LC/APCI/MS das frações alcaloídicas de U. guatterioides foi possível confirmar a presença dos alcalóides anonaina, asimilobina, liriodenina e lisicamina, já reportados na literatura da espécie, identificar pela primeira vez no gênero o alcalóide nornuciferina, além de sugerir a presença de um alcalóide do tipo azafluorenona, previamente reportado na espécie U. lindimanii. A investigação espectrométrica de U. duckei revelou a existência de alcalóides aporfínicos e oxoaporfínicos já reportados no gênero, bem como conduziu ao isolamento do alcalóide aporfínico glaziovina e de uma mistura de glaucina e norglaucina, sendo todos esses alcalóides inéditos no gênero. Foi realizado o isolamento do triterpeno policarpol de ambas as espécies, sendo o melhor rendimento observado em U. duckei. A investigação dos constituintes menos polares de U. guatterioides levou ao isolamento de misturas de sitosterol/estigmasterol. Das frações alcaloídicas de U. duckei e U. guatterioides analisadas, quatro foram consideradas altamente ativas, uma ativa e apenas uma não se apresentou ativa frente a Leishmania amazonensis. Entre as substâncias avaliadas, o alcalóide glaziovina apresentou alta atividade frente a Leishmania amazonensis.

Actinomycetes and fungi were successfully isolated from both New Zealand and Malaysian marine invertebrates and classified as facultatively marine based on their ability to grow on both sea water and non-sea water media. Most of the extracts obtained from selected isolates were cytotoxic. A clear preference of the actinomycetes for solid-state fermentation was observed, however, for fungi no significant preference was seen. Three isolates of Streptomyces spp., four Penicillium spp. and two Paecilomyces spp. whose extracts showed good cytotoxicity were selected for further investigation. A small-scale extract obtained from a solid culture of Streptomyces sp. (LA3L2) showed good cytotoxicity and a new cytotoxic metabolite was isolated from a large-scale extract of Streptomyces sp. (LA3L2). This metabolite was characterized as S-methyl 2,4-dihydroxy-6-isopropyl-3,5-dimethylbenzothioate (5.15) and is only the third compound reported to contain the S-methyl benzothioate group. Two known compounds, montagnetol (5.16) and erythrin (5.18), were isolated from a further large-scale cultivation of Streptomyces sp. (LA3L2) and is the first reported actinomycete to produce these lichen-related compounds. In addition, two known inactive metabolites (bohemamine (5.1) and bohemamine B (5.2)) were identified from the small-scale extract. Streptomyces sp. (LA3L2) was also investigated for the effect of temperature and salinity on growth and cytotoxicity and shown to produce bohemamine only at 20 - 28℃ and 4% sea salt concentration on solid media. This isolate gave a low yield of active metabolite under all conditions. Small-scale extracts of two other Streptomyces spp. yielded three known cytotoxic metabolites. These were thiazostatin B (7.14) from Streptomyces sp. (LA5L4) and chromomycin A2 (7.1), chromomycin A3 (7.2) and chromomycin 02-3D (7.3) from Streptomyces sp. (LA3L1). All four Penicillium spp. produced known metabolites. Penicillium sp. (LY1L5) yielded two known metabolites, cycloaspeptide A (7.4) and α-cyclopiazonic acid (7.5). α-Cyclopiazonic acid (7.5) and three other known metabolites (roquefortine A (7.6), cyclopeptin (7.7) and viridicatin (7.8)) were isolated from Penicillum sp. (KK3T23). Penicillium sp. (KK3T8) produced brefeldin A (7.10), while mycophenolic acid (7.12) and brevianamide A (7.11) were produced by Penicillium sp. (KK4T14b). The effect of salinity on growth and cytotoxicity was investigated for the two Penicillium isolates producing the cytotoxic metabolite, α-cyclopiazonic acid (7.5). Saline conditions were not required for growth but metabolite production differed between the two isolates with respect to salinity. Isolate LY1L5 required saline conditions for α-cyclopiazonic production whereas isolate KK3T23 produced the metabolite under non-saline conditions and in concentrations of sea salt up to 6%. Three known compounds, indole-3-carboxylic acid (7.15), indole-3-carboxylate (7.17) and 5-carboxymellein (7.16) were identified from Paecilomyces sp. (PR5L9). Investigation of a small-scale extract obtained from a solid culture of another Paecilomyces sp. (PR10T2) resulted in the isolation and characterization of a unique structure of a symmetrical cyclic depsipeptide, epi-angolide (NAM 6-1). NAM 6-1 was considered as a new compound based on four homoisomeric configurations (A1, A2, A3 and A4). The value of dereplication procedures with respect to the rapid identification of metabolites and enhancement of in-house metabolite libraries is discussed. Structural elucidation of nine known metabolites (7.1, 7.2, 7.3, 7.5, 7.6, 7.7, 7.8, 7.10 and 7.11) was greatly aided by the in-house dereplication techniques using LC-MS-UV and AntiMarin database. A significant advantage was gained by the use of the CapNMR which enabled NMR characterization of very small quantities of metabolites (<20 µg). Approximately <5 µg of materials were required to perform 1D proton NMR experiments for the dereplication of seven known compounds; bohemamine (5.1), bohemamine B (5.2), thiazostatin B (7.14), indole-3-carboxylate (7.17) and 5-carboxymellein (7.16). Approximately 20 µg of materials were needed to acquire 1D and 2D (HSQC, HMBC and NOE) NMR spectra for structural elucidation of the new metabolite, S-methyl 2,4-dihydroxy-6-isopropyl-3,5-dimethylbenzothioate (5.15). Some 8 µg of materials were sufficient to perform 1D and 2D (COSY, HSQC and HMBC) NMR experiments for complete structural characterization of two known metabolites, montagnetol (5.16) and erythrin (5.18). Approximately 10 µg of materials were needed to acquire 1D and 2D NMR (COSY, HSQC and HMBC) experiments for structural elucidation of the new compound, epi-angolide NAM 6-1 (A1, A2, A3 and A4). Rapid identification of known fungal metabolites enabled the in-house HPLC-UV/Rt library to be enhanced by eight metabolites (7.5, 7.6, 7.7, 7.8, 7.10, 7.11, 7.17 and 7.16). An HPLC-UV/Rt library for actinomycete metabolites was successfully established with the insertion of eight known metabolites (5.1, 5.2, 5.16, 5.18, 7.1, 7.2, 7.3 and 7.14).