New polyoxygenated steroids from the South China Sea gorgonian Echinogorgia aurantiaca.

Three new polyoxygenated steroids, named 3beta,7alpha,9alpha-trihydroxy-cholestan-6-one (1), 3beta,5alpha,6beta-trihydroxycholestan-1-one (2) and cholestane-3beta,5alpha,6beta,11beta-tetrol (3), along with four known steroids (4-7) were isolated from the South China Sea gorgonian Echinogorgia aurantiaca. The structures of 1-3 were established by extensive spectroscopic analysis, including 1D and 2D NMR data.