The structural determination of a new steroidal metabolite from the brown alga Sargassum asperifolium

Abstract

An investigation of the natural products chemistry of the brown alga Sargassum asperifolium from the red sea yielded a new steroidal metabolite, 24-vinyl cholest -4-ene -24- ol -3 one, saringosterone (3), a known steroidal metabolite, 24-vinyl cholest -5-ene -3b, 24-diol, saringosterol (4), and known diterpene with a hydroazulene skeleton, dictyone (1). The identification of the isolated metabolites was established mainly by spectral methods and chemical transformation of the dictyone (1) to its acetate (2).