Bioactive Compounds from a Gorgonian Coral <em>Echinomuricea</em> sp. (Plexauridae)

Abstract

A new labdane-type diterpenoid, echinolabdane A (<strong>1</strong>), and a new sterol, 6-<em>epi</em>-yonarasterol B (<strong>2</strong>), were isolated from a gorgonian coral identified as <em>Echinomuricea</em> sp. The structures of metabolites <strong>1</strong> and <strong>2</strong> were elucidated by spectroscopic methods. Echinolabdane A (<strong>1</strong>) possesses a novel tetracyclic skeleton with an oxepane ring jointed to an α,β-unsaturated-γ-lactone ring by a hemiketal moiety, and this compound is the first labdane-type diterpenoid to be obtained from marine organisms belonging to the phylum Cnidaria. 6-<em>epi</em>-Yonarasterol B (<strong>2</strong>) is the first steroid derivative to be isolated from gorgonian coral belonging to the genus <em>Echinomuricea</em>, and this compound displayed significant inhibitory effects on the generation of superoxide anions and the release of elastase by human neutrophils.

Keywords

• &lt;em&gt;Echinomuricea&lt;/em&gt;
• echinolabdane
• yonarasterol
• superoxide anion
• elastase