抄録
Nine polyhydroxysterols were isolated from the lipid extract of two Sclerophytum sp. soft corals collected in the Andaman and Nicobar Islands. Of these, three compounds (7a, b, and 8) had previously been isolated from the southern Japan soft coral Sarcophyton glaucum. Compound 1 was identified as lobosterol having a novel 6-keto-A/B-cis ring juncture. The structures of the five new compounds were determined as 25-deacetyllobosterol (2), (24S)-24-methylcholest-7-ene-3β, 5α, 6β, 25-tetrol 25-monoacetate (3), (24S)-24-methylcholest-22E-ene-3β, 5α, 6β, 25-tetrol (4), (24S)-24-methylcholestane-3β, 5α, 25-triol-6-one 25-monoacetate (5a) and its C-25 deacetoxy analog (6), from the spectral data and by chemical conversion.