Novel sterols from the finger sponge Haliclona oculata

Abstract

From the finger sponge, Haliclonaoculata (Linnaeus), six new polar sterols have been isolated and their structures determined by chemical and spectroscopic means. These are 3β-hydroxy-cholesta-5,25-dien-24-one (2), 3β-hydroxy-24-methylene-5-cholesten-7-one (6), 24-methylene-5-cholesten-3β,7β-diol (9), 24-methylcholesta-5,22-dien-3β,7β-diol (11), 24-methylene-5-cholesten-3β,7α-diol (12), and 5β,6-epoxy-24-methylene-cholestan-3β-ol (16). Also shown to be present are the known monohydroxysterols (22E,24S)-24-methylcholesta-5,22-dien-3β-ol (1), (22Z)-24-norcholesta-5,22-dien-3β-ol, 24-methylene-5-cholesten-3β-ol, 24-isoethylidene-5-cholesten-3β-ol, (22E)-24-norcholesta-5,22-dien-3β-ol and (23E)-cholesta-5,23-dien-3β,25-diol. The structure 14 is tentatively proposed for a novel C 24 sterol and 8 is suggested for the structure of a compound accompanying 6.