Isolation of a new anti-inflammatory 20, 21, 22, 23, 24, 25, 26, 27-octanorcucurbitacin-typetriterpene from Ibervillea sonorae

Abstract

A new cucurbitane-type triterpene, 20, 21, 22, 23, 24, 25, 26, 27-octanorcucurbita-5-ene-3, 11, 16-trione (1), named kinoin D, was isolated from the roots of the medicinal plant Ibervillea sonorae, (wereque). The structure of 1 was established on the basis of extensive NMR and MS studies. In addition, the known kinoins B (3) and C (5) were isolated, as were 16α-20,25-trihydroxy-3α-(2-O-α-L-rhamnopyranosiyl-β- glucopyranosyloxy)-(10α)-cucurbit-5-en-11,22-dione (6), (22 S)-16α,22-diacetoxy-20,25-dihydroxy-3α-[3,4,6-tri-O-acetyl-2-O-(2,3, 4-tri-O-acetyl-α-L-rhamnopyranosyl)-β-glucopyranosyl]-(10α) -cucurbita-5,23t-dien- 11-one (7) and 16α-acetoxy-20,25-dihydroxy- 3α-[3,4,6-tri-O-acetyl-2-O-(2,3,4,-tri-O-acetyl-α-L-rhamnopyranosyl) -β-D-glucopyranosyl]-(10α)-cucurbita- 5-ene-11,22-dione (8). Compound 1 exhibited anti-inflammatory activity in TPA-induced edema in mice.