Discovery of Novel Diterpenoids from Sinularia arborea

Two novel diterpenoids, sinularbols A (1) and B (2), which were found to possess a new carbon skeleton were isolated from the soft coral Sinularia arborea. The structures of compounds 1 and 2 were elucidated by spectroscopic methods and 2 displayed a moderately inhibitory effect on the generation of superoxide anion by human neutrophils.