Briarenol L, a new chlorine-containing briarane from Briareum excavatum (Briareidae)

Chemical examination of Briareum excavatum, collected in the waters of Taiwan, led to the isolation of four briarane diterpenoids, including three known compounds, briarenol G (1), briaviolides Y (2), and Z (3), as well as a new metabolite, briarenol L (4). The absolute configuration of 1 was determined by a single-crystal X-ray diffraction analysis for the first time in this study and the structure of 4 was established on the basis of spectroscopic analysis. Briaranes 2 and 3 exerted inhibition effects on COX-2 and iNOS, respectively, release from RAW 264.7 macrophages. (C) 2020 Elsevier B.V. All rights reserved.