Cytotoxic cembrenolides and steroids from the formosan soft coral Sarcophyton crassocaule.

Three new cytotoxic cembrenolide diterpenes, sarcocrassolide (1), crassolide (2), and 13-acetoxysarcocrassolide (3); a known cytotoxic cembrenolide, denticulatolide (4); and two cytotoxic steroids, (24S)-24-methylcholestane-3beta,5alpha,6beta-triol (5) and 24zeta-methylcholestane-3beta,5alpha,6beta,25-te traol-25-monoacetate (6), have been isolated from the Formosan soft coral Sarcophyton crassocaule. The structures of compounds 1-6 were determined by 1D and 2D spectral analysis.