RESUMO
A new pregnane, 3α-hydroxy-7-ene-6,20-dione (1), and five known steroids (2-6), along with one known steroidal glycoside (7) were obtained from the fungus Cladosporium sp. WZ-2008-0042 cultured from a gorgonian Dichotella gemmacea collected from the South China Sea. The structure and absolute configuration of the new compound (1) were elucidated by comprehensive spectroscopic data and X-ray diffraction data. The compound has a rare configuration of 3α-OH that is different from most of pregnanes. All of the isolated compounds were evaluated for their antiviral activities against respiratory syncytial virus (RSV). Among them, 1 exhibited potential antiviral activity with the IC50 value of 0.12 mM.
Assuntos
Antivirais/farmacologia , Cladosporium/química , Pregnanos/química , Animais , Antozoários/microbiologia , Antibacterianos/química , Antibacterianos/farmacologia , Antivirais/química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Glicosídeos/química , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Estrutura Molecular , Pregnanos/farmacologia , Vírus Sinciciais Respiratórios/efeitos dos fármacos , Espectrometria de Massas por Ionização por Electrospray , Esteroides/química , Difração de Raios XRESUMO
A pair of new enantiomeric alkaloid dimers, (+)- and (-)-pestaloxazine A (1), with an unprecedented symmetric spiro[oxazinane-piperazinedione] skeleton, consisting of 22 carbons and 12 heteroatoms, were isolated from a Pestalotiopsis sp. fungus derived from a soft coral. Separation of the enantiomeric alkaloid dimers was achieved by chiral HPLC. Their structures including absolute configurations were elucidated on the basis of a comprehensive analysis of their spectroscopic and X-ray diffraction data and CD calculations. (+)-Pestaloxazine A exhibited potent antiviral activity against EV71 with an IC50 value of 14.2 ± 1.3 µM, which was stronger than that of the positive control ribavirin (IC50 = 256.1 ± 15.1 µM).