A cytotoxic 5 alpha,8 alpha-epidioxysterol from a soft coral Sinularia species

A new sterol, (22R,23R,24R)-5 alpha,8 alpha-epidioxy-22,23-methylene-24-methylcholest-6-en-3 beta-ol (1), as well as two known sterols, numersterol A (2) and pregnenolone (3), have been isolated from a soft coral Sinularia sp. The structure of metabolite 1 was determined by spectral analysis. Cytotoxicity of sterols 1-3 toward various cancer cell lines is also reported.