Six 6-chlorine-containing briarane analogues, including two new compounds, briarenols U (1) and V (2), as well as four known metabolites, solenolides B (3) and E (4); briaexcavatolide E (5); and brianolide (6) were isolated from an octocoral identified as Briareum stechei. The structures of compounds 1-6 were elucidated by using spectroscopic methods, and the stereochemistry of solenolide B (3) was revised. The absolute configuration of 6 was further determined by a single-crystal X-ray diffraction analysis. Briarane 1 was found to induce significant in vitro inflammatory activity in LPS-induced RAW264.7 macrophage cells by enhancing the expression of iNOS and COX-2 protein. (C) 2021 Elsevier Ltd. All rights reserved.
