RESUMO
A new lactone, 7-epi-griffonilide (1), and six known compounds, 2, 3a - 3c, 4a and 4b, were isolated from the leaves of Bauhinia pentandra (Fabaceae). The structures elucidation of 1 and 2 were based on detailed 2D NMR techniques and spectral comparison with related compounds, leading to complete assignment of the 1H and 13C NMR spectra.
Assuntos
Bauhinia/química , Lactonas/química , Lactonas/isolamento & purificação , Folhas de Planta/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13/métodos , Estrutura Molecular , Espectroscopia de Prótons por Ressonância Magnética/métodos , Valores de Referência , EstereoisomerismoRESUMO
The cytotoxic activities of extracts (50â µg/ml) from 48 fungal strains, recovered from sediments of Pecém's offshore port terminal (Northeast coast of Brazil), against HCT-116 colon cancer cell lines were investigated. The most promising extract was obtained from strain BRF082, identified as Dichotomomyces cejpii by phylogenetic analyses of partial RPB2 gene sequence. Thus, it was selected for bioassay-guided isolation of the cytotoxic compounds. Large-scale fermentation of BRF082 in potato dextrose broth, followed by chromatographic purification of the bioactive fractions from the liquid medium, yielded gliotoxin (4) and its derivatives acetylgliotoxin G (3), bis(dethio)bis(methylsulfanyl)gliotoxin (1), acetylgliotoxin (5), 6-acetylbis(dethio)bis(methylsulfanyl)gliotoxin (2), besides the quinazolinone alkaloid fiscalin B. All isolated compounds were tested for their cytotoxicities against the tumor cell lines HCT-116, revealing 4 and 3 as the most cytotoxic ones (IC50 0.41 and 1.06â µg/ml, resp.).
Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Fungos/química , Sedimentos Geológicos/microbiologia , Antineoplásicos/isolamento & purificação , Produtos Biológicos/isolamento & purificação , Brasil , Neoplasias do Colo/tratamento farmacológico , Fungos/genética , Gliotoxina/análogos & derivados , Gliotoxina/química , Gliotoxina/isolamento & purificação , Gliotoxina/farmacologia , Células HCT116 , Humanos , Indóis/química , Indóis/isolamento & purificação , Indóis/farmacologia , Filogenia , Quinazolinas/química , Quinazolinas/isolamento & purificação , Quinazolinas/farmacologiaRESUMO
Three new 3-hydroxy-N-methyl-2-oxindole (1 and 2) and 4-hydroxy-pyran-2-one (3) derivatives, along with the known 3-hydroxy-N-methyl-2-oxindole (4) and 6-methoxy-N-methylisatin (5) were isolated from a marine Salinispora arenicola strain from sediments of the St. Peter and St. Paul Archipelago, Brazil. The structures of the new compounds were elucidated by a combination of spectroscopic (1D and 2D NMR and HR-ESIMS) data, including single-crystal X-ray diffraction analysis for 2 and 3. Compounds 1 to 5 were assayed for their antimicrobial properties, but only 4 and 5 were active against Enterococcus faecalis with MIC value of 15.6⯵g/mL.
Assuntos
Antibacterianos/farmacologia , Sedimentos Geológicos/microbiologia , Micromonosporaceae/química , Oxindóis/farmacologia , Antibacterianos/isolamento & purificação , Brasil , Enterococcus faecalis/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Oxindóis/isolamento & purificação , Água do Mar/microbiologiaRESUMO
ABSTRACT A new lactone, 7-epi-griffonilide (1), and six known compounds, 2, 3a - 3c, 4a and 4b, were isolated from the leaves of Bauhinia pentandra (Fabaceae). The structures elucidation of 1 and 2 were based on detailed 2D NMR techniques and spectral comparison with related compounds, leading to complete assignment of the 1H and 13C NMR spectra.