12-epi-Briacavatolide B, a New Briarane Diterpenoid from the Octocoral Briareum stechei

Abstract

A new briarane-type diterpenoid, 12-epi-briacavatolide B (1), along with its known epimer, briacavatolide B (2), were purified from an octocoral identified as Briareum stechei. Spectroscopic approaches were used to reveal the structure of new briarane 1.Octocorals are invertebrates extensively distributed in coastal waters, especially the coasts of tropical and subtropical Indo-Pacific Ocean regions. The creatures have been shown to be rich sources of an array of diterpenoid derivatives with characteristic carbon skeletons that have various bioactivities. 1,2 The octocorals belonging to genus Briareum (phylum: Cnidaria, sub-phylum: Anthozoa, class: Octocorallia,