New polyhydroxylated steroid from the South China Sea gorgonian Anthogorgia caerulea.

One new polyhydroxylated steroid, caerulsteroid A (1), along with nine known analogues (2-10), was isolated from the gorgonian coral Anthogorgia caerulea collected from the South China Sea. The structure of the new compound was elucidated by 1-D and 2-D NMR, and mass spectrometry. The absolute configuration of 1 was assigned on the basis of the absolute configurations of the related congeners 2 and 3, which were determined by application of the modified Mosher's method. The isolated compounds were assayed for their cytotoxicity, antimicrobial activity and lethality towards brine shrimp Artemia salina.