Novel Caryophyllane-Related Sesquiterpenoids with Anti-Inflammatory Activity from (Linnaeus, 1758).

Two previously undescribed caryophyllane-related sesquiterpenoids, antipacids A () and B (), with a novel bicyclo[5.2.0] core skeleton, and known compound clovane-2β,9α-diol (), along with rumphellolide L (), an esterified product of and , were isolated from the organic extract of octocoral . Their structures, including the absolute configurations were elucidated by spectroscopic and chemical experiments. In vivo anti-inflammatory activity analysis indicated that antipacid B () inhibited the generation of superoxide anions and the release of elastase by human neutrophils, with IC values of 11.22 and 23.53 μM, respectively, while rumphellolide L () suppressed the release of elastase with an IC value of 7.63 μM.