Anti-Inflammatory Cembranoids from the Soft Coral Lobophytum crassum

Abstract

<b>Abstract</b><b>:</b> Cembrane-type diterpenoids are among the most frequently encountered natural products from the soft corals of the genus <i>Lobophytum</i>. In the course of our investigation to identify anti-inflammatory constituents from a wild-type soft coral <i>Lobophytum</i><i>crassum</i>, two new cembranoids, lobophyolide A (<b>1</b>) and B (<b>2</b>), along with five known compounds (<b>3</b>-<b>7</b>), were isolated. The structures of these natural products were identified using NMR and MS spectroscopic analyses. Compound <b>1</b> was found to possess the first identified <i>α</i>-epoxylactone group among all cembrane-type diterpenoids. The in vitro anti-inflammatory effect of compounds 1-<b>5</b> was evaluated. The results showed that compounds 1-<b>5</b> not only reduced IL-12 release, but also attenuated NO production in LPS-activated dendritic cells. Our data indicated that the isolated series of cembrane-type diterpenoids demonstrated interesting structural features and anti-inflammatory activity which could be further developed into therapeutic entities.