Four New Compounds from the Australian Brown Alga Cystophora brownii

Abstract

Two new steroids, (20S)-3β,20-dihydroxyergosta-5,24(28)-dien-16-one (7) and 3β-hydroxyergosta-5,24(28)-dien-16-one (9), and two new diastereoisomeric meroditerpenes, compounds (10) and (11), † have been isolated from the brown alga Cystophora brownii (Cystoseiraceae). Their structures were elucidated by one- and two-dimensional n.m.r. and other spectrometric and chemical methods.