RESUMO
Five cadinane sesquiterpenes derivatives were isolated by bioassay-guided fractionation from Phomopis cassiae, an endophytic fungus isolated from Cassia spectabilis. The structures of the two diastereoisomeric 3,9,12-trihydroxycalamenenes (1, 2); 3,12-dihydroxycalamenene (3); 3,12-dihydroxycadalene (4) and 3,11,12-trihydroxycadalene (5) were established on the basis of analyses of 1D and 2D NMR and HRTOFMS experiments. Antifungal activity of the isolates was evaluated against Cladosporium sphaerospermum and Cladosporium cladosporioides, revealing 5 as the most active compound.
Assuntos
Ascomicetos/química , Cassia/microbiologia , Sesquiterpenos/isolamento & purificação , Antifúngicos/química , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Ascomicetos/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Cladosporium/efeitos dos fármacos , Células HeLa , Humanos , Espectroscopia de Ressonância Magnética/métodos , Estrutura Molecular , Sesquiterpenos Policíclicos , Sesquiterpenos/química , Sesquiterpenos/farmacologia , Relação Estrutura-AtividadeRESUMO
Three seco-iridoids 7-methoxydiderroside, 6'-O-acetyldiderroside and 8-O-tigloyldiderroside, were isolated from the wood bark of Calycophyllum spruceanum together with the known iridoids loganetin, loganin and the seco-iridoids secoxyloganin, kingiside and diderroside. Their structures were elucidated by means of NMR and MS spectral data analysis. Using NOE correlations and coupling constants, the relative stereochemistry of the new derivatives was established. 7-Methoxydiderroside, 6'-O-acetyldiderroside and the known secoxyloganin and diderroside showed in vitro activity against trypomastigote forms of Trypanosoma cruzi, with IC(50) values of 59.0, 90.2, 74,2 and 84.9 microg/mL, respectively and were compared to the standard gentian violet (IC(50) 7.5 microg/ml).