[Steroid Compounds from the Far East Starfish Pteraster Obscurus and the Ophiura Asteronyx Loveni]

Seven sulfated polyhydroxysteroids were isolated from the Far East starfish Pteraster obscurus and the ophiura (snake star) Asteronyx loveni (collected in the Sea of Okhotsk) and characterized: disodium and sodium salts of (20R)-24-methyl-2beta-hydroxycholesta-5,24(28)-diene-3alpha,21-diyl disulfate, (20R)-5alpha-cholestane-3beta,21-diyl disulfate, (20R)-3beta-hydroxy-5alpha-cholestan-21-yl sulfate, (20R)-cholest-5-ene-3beta,21-diyl disulfate, (20R)-2beta-hydroxycholest-5-ene-3alpha,21-diyl disulfate, (20R)-cholest-5-en-3beta-yl sulfate, and (20R)-5alpha-cholestan-3beta-yl sulfate. The first four compounds turned out to be new, whereas the others were identical to the known compounds. Structures of the isolated steroids were identified by two-dimensional NMR spectroscopy and other physicochemical methods. The compounds isolated from starfish are structurally similar to typical ophiuroid metabolites, which support the opinion of some taxonomists that starfish and ophiuroids are phylogenetically related classes.