A new hexahydrobenzopyran derivative from the gorgonian-derived Fungus Eutypella sp.

A new hexahydrobenzopyran derivative cytosporin L (1), and another eight known compounds were isolated from the gorgonian-derived fungus Eutypella sp. collected from the South China Sea. The structure of 1 was elucidated by comprehensive spectroscopic data. The absolute configuration of 1 was determined by a chemical reaction and the modified Mosher's method. The isolated secondary metabolites were evaluated for their antibacterial activities. Compound 1 showed antibacterial activity towards Micrococcus lysodeikticus and Enterobacter aerogenes with the same MIC values of 3.12 μM. Compounds 1-3 were evaluated for antiviral activities. Compounds 1 and 2 obviously inhibited the respiratory syncytial virus (RSV) with the IC50 values of 72.01 and 30.25 μM, respectively.