Abstract

The norditerpene diene acid (4) and norsesterterpene diene acid (5), along with their corresponding methyl esters (6) and (7), were isolated from an Australian marine sponge, Latrunculia brevis, and their structures determined by detailed spectroscopic analysis, chemical derivatization and degradation. Comment is made on the possible intermediacy of dienes such as (4)-(7) in the biosynthesis of norterpene cyclic peroxides, common to other Latrunculia species from the same locality.