A bioactive secosterol with an unusual A- and B-ring oxygenation pattern isolated from an Indonesian soft coral Lobophytum sp.

A secosterol with a gorgosterol side chain and an unusual oxygenation pattern on the A and B rings was isolated from an Indonesian soft coral Lobophytum sp. The A and B rings of the reported compound 1 have hydroxyl groups at C-3 and C-7 and an epoxide ring at C-5-C-6. The structure of 1 was solved by 2D NMR methods and by chemical shift analogy to the known secogorgosterol 2. Compound 1 was found to have activity against human ovarian tumor and human leukemia cell lines.