Kaurane-type diterpene glycoside from the stem bark of Acanthopanax trifoliatus

Abstract

A new diterpene glycoside, acantrifoside D (1), as well as three known diterpenes (2-4) were isolated from the stem bark of Acanthopanax trifoliatus from Vietnam. Based on 1D and 2D NMR spectroscopic data, their chemical structures were determined to be 16α,17-dihydroxy-ent-kauran-19-oic acid 16-O-β-D-glucopyranoside 19-O-β-D-glucopyranosyl ester (1), 16αH,17-isovalerate-ent-kauran-19-oic acid (2), ent-kaur-16-en-19-oic acid (3), and ent-pimara-8(14),15-dien-19-oic acid (4). Compounds 2-4 had strong inhibitory effects against COX-1 in an in vitro assay, with IC 50 values of 0.21, 0.15 and 0.19 mM, respectively.