Antibacterial modified diketopiperazines from two ascidians of the genus Didemnum

The chemical investigation of the crude extract of an ascidian of the genus Didemnumled to the isolation of the modified diketopiperazine rodriguesines A (1) and (2) as a mixture of homologues, which could be identified by analysis of spectroscopic data including MS/MS experiments. The investigation of a second Didemnumsp. led to the isolation of N-acetyl-rodriguesine A (3) and N-acetyl-rodriguesine B (4). The absolute configuration of compounds 1and 2could be established by hydrolysis and Marfey's analysis and comparison with literature data reported for compound 3, previously obtained as a synthetic product. The mixture of 1and 2displayed moderate antibiotic activity against a clinical isolate of Streptococcus mutansand against S. mutansUA159 and Staphylococcus aureusATCC6538.A investigação química do extrato bruto de uma ascidia do gênero Didemnumlevou ao isolamento das dicetopiperazinas modificadas rodriguesinas A (1) e B (2) na forma de uma mistura de homólogos, os quais puderam ser identificados pela análise de seus dados espectroscópicos inclusive experimentos MS/MS. A investigação de uma segunda ascídia do gênero Didemnumforneceu a N-acetil-rodriguesina A (3) e a N-acetil-rodriguesina B (4). A configuração absoluta dos compostos 1e 2pode ser estabelecida por hidrólise e análise de Marfey e por comparação com dados da literatura do composto 3,previamente obtido como produto de síntese. A mistura de 1e 2apresentou atividade antibiótica moderada contra um isolado clínico de Streptococcus mutans, contra S. mutans UA159 e S. aureusATCC6538.American Society of PharmacognosyFAPESP - BIOprospecTACoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)FulbrightCNPqFAPES

Antibacterial modified diketopiperazines from two ascidians of the genus Didemnum

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The chemical investigation of the crude extract of an ascidian of the genus Didemnumled to the isolation of the modified diketopiperazine rodriguesines A (1) and (2) as a mixture of homologues, which could be identified by analysis of spectroscopic data including MS/MS experiments. The investigation of a second Didemnumsp. led to the isolation of N-acetyl-rodriguesine A (3) and N-acetyl-rodriguesine B (4). The absolute configuration of compounds 1and 2could be established by hydrolysis and Marfey's analysis and comparison with literature data reported for compound 3, previously obtained as a synthetic product. The mixture of 1and 2displayed moderate antibiotic activity against a clinical isolate of Streptococcus mutansand against S. mutansUA159 and Staphylococcus aureusATCC6538.A investigação química do extrato bruto de uma ascidia do gênero Didemnumlevou ao isolamento das dicetopiperazinas modificadas rodriguesinas A (1) e B (2) na forma de uma mistura de homólogos, os quais puderam ser identificados pela análise de seus dados espectroscópicos inclusive experimentos MS/MS. A investigação de uma segunda ascídia do gênero Didemnumforneceu a N-acetil-rodriguesina A (3) e a N-acetil-rodriguesina B (4). A configuração absoluta dos compostos 1e 2pode ser estabelecida por hidrólise e análise de Marfey e por comparação com dados da literatura do composto 3,previamente obtido como produto de síntese. A mistura de 1e 2apresentou atividade antibiótica moderada contra um isolado clínico de Streptococcus mutans, contra S. mutans UA159 e S. aureusATCC6538.204704711American Society of PharmacognosyFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FulbrightConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq_BrasilFAPESP_BrasilCAPES_Brasi

Evaluating methods for the isolation of marine-derived fungal strains and production of bioactive secondary metabolites

In the present investigation we evaluate methods for the isolation and growth of marine-derived fungal strains in artificial media for the production of secondary metabolites. Inoculation of marine macroorganisms fragments in Petri dishes proved to be the most convenient procedure for the isolation of the largest number of strains. Among the growth media used, 3% malt extract showed the best result for strains isolation and growth, and yielded the largest number of strains from marine macroorganisms. The percentage of strains isolated using each of the growth media which yielded cytotoxic and/or antibiotic extracts was in the range of 23-35%, regardless of the growth media used. Further investigation of extracts obtained from different marine-derived fungal strains yielded several bioactive secondary metabolites, among which (E)-4-methoxy-5-(3-methoxybut-1-enyl)-6-methyl-2H-pyran-2-one is a new metabolite isolated from the Penicillium paxilli strain Ma(G)K.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Isolamento e atividades biológicas de produtos naturais das esponjas monanchora arbuscula, aplysina sp. petromica ciocalyptoides e topsentia ophiraphidites, da ascídia didemnum ligulum e do octocoral carijoa riisei

The investigation of extracts from six species of marine invertebrates yielded one new and several known natural products. Isoptilocaulin from the sponge Monanchora aff. arbuscula displayed antimicrobial activity at 1.3 mg/mL against an oxacillin-resistant strain of Staphylococcus aureus. Five inactive known dibromotyrosine derivatives, 2 6, were isolated from a new species of marine sponge, Aplysina sp. The sponges Petromica ciocalyptoides and Topsentia ophiraphidites yielded the known halistanol sulfate A (7) as an inhibitor of the antileishmanial target adenosine phosphoribosyl transferase. The ascidian Didemnum ligulum yielded asterubin (10) and the new N,N-dimethyl-O-methylethanolamine (11). The octocoral Carijoa riisei yielded the known 18-acetoxypregna-1,4,20-trien-3-one (12), which displayed cytotoxic activity against the cancer cell lines SF295, MDA-MB435, HCT8 and HL60