Rumphellclovane B, a Novel Clovane Analogue from the Gorgonian Coral Rumphella antipathies

A novel clovane-type sesquiterpenoid derivative, rumphellclovane B (1), which possesses an unprecedented delta-lactone moiety, and a new natural clovane, 9 alpha-hydroxyclovan-2-one (2), were isolated from the gorgonian coral Rumphella antipathies. The structures of clovanes 1 and 2 were elucidated by interpretations of spectral data. A plausible biosynthetic pathway between these two compounds was proposed. Compound 1 displayed inhibitory effects on superoxide anion generation by human neutrophils.