A New 5α,8α-Epidioxysterol from the Soft Coral Sinularia gaweli

A new sterol, (22R,23R,24R)-5 alpha,8 alpha-epidioxy-22,23-methylene-24-methylcholest-6,9( 11)-dien-3 beta-ol (1), and two known sterols, (22R, 23R, 24R)-5 alpha,8 alpha-epidioxy-22,23-methylene-24-methylcholest-6-en-3 beta-ol (2) and 24-methylenecholestane-1 alpha,3 beta,5 alpha, 6 beta,11 alpha-pentol (3), were isolated from the soft coral Sinularia gaweli. The structure of sterol 1 was established by spectroscopic methods and by comparison of the spectral data with those of known analogues. The cytotoxicity of sterols 1-3 towards various tumor cells is reported.