Cembranoid diterpenes from soft coral Sinularia sp.

A soft coral Sinularia sp., collected from the South China Sea, was selected to investigate the bioactive and chemical constituents. The EtOAc fraction were isolated by repeatedly silica gel and Sephadex LH-20 column chromatography to obtain lobophytolide A (1), 3-dehydroxylpresinularolide B (2), sarcophine (3), 3 beta-acetoxyisolobophytolide (4), Crassocolide D (5), (3E,7E,11E)-6-acetoxy-3,7,11,15(17)-cembratrien-16,14-olide (6). The structures of compounds 1-6 were determined on the basis of spectroscopic data analysis. All compounds were tested against a small panel of human tumor cell lines. And these compounds were obtained for the first time from this coral.