2-Acetoxybriaranes from Briareum violaceum

Five 2-acetoxybriaranes, including two known analogues, excavatolides B (1), E (2), along with three new metabolites, briaviolides V-X (3-5), have been obtained from the octocoral Briareum violaceum. The absolute configurations of I and 2 were determined by X-ray analysis for the first time and the structures of 3-5 were established by spectroscopic methods. Bioactivity study showed that briarane 3 decreased the release of elastase from human neutrophils. (C) 2019 Elsevier Ltd. All rights reserved.