Marine Sterols. XXV. Isolation of 23-Demethylgorgost-7-ene-3.BETA.,5.ALPHA.,6.BETA.-triol and (24S)-Ergostane-3.BETA.,5.ALPHA.,6.BETA.,7.BETA.,15.BETA.-pentol from Soft Corals of the Andaman and Nicobar Coasts.

Abstract

Two new marine polyhydroxysterols, 23-demethylgorgost-7-ene-3β, 5α, 6β-triol (4a) and (24S)-ergostane-3β, 5α, 6β, 7β, 15β-pentol (6), were isolated from soft corals(Sinularia sp. and Lobophytum crassum, respectively) collected off the Andaman and Nicobar Islands, Indian Ocean. (24S)-Ergost-5-ene-3β, 7α-diol (1), a known synthetic compound, was isolated from Sclerophytum sp. soft coral of the same region. The structures of 4a and 6 were derived by comparison of the 1H- and 13C-NMR data with those of reference compounds having the same partial structures. The previous assignments of C-1 and C-2 of 3β, 5α, 6β-trihydroxysterol were reversed.