Four new polyoxygenated gorgosterols from the gorgonian Isis hippuris.

Four new polyoxygenated steroids (1-4) together with four known ones (5-8) have been isolated from the gorgonian Isis hippuris. The structures of the new compounds have been elucidated by spectroscopic analysis and chemical conversion. All of the new steroids showed moderate cytotoxicity against cultured NBT-T2 cells.