A new ursane-type nor-triterpenoid from the leaves of Eucommia ulmoides oliv

Abstract

A new ursane-type nortriterpenoid, (11S,12S)-4-methyl-11,12-epoxy-2- hydroxy- 3-oxoursa-1,4-dine-28-oic acid γ-lactone (1), named ulmoidol A, together with ten known compounds: ulmoidol (2), corosolic acid (3), 2α,3α-dihydroxy-24-nor-4(23),12-oleanadien- 28-oic acid (4), oleanolic acid (5), ursolic acid (6), cycloart-3β, 25-diol (7), foliasalacioside B1 (8), (6R,7E,9R)-9-hydroxy-4,7-megastigmadien-3-one-9-O-A-L- Arabinopyranosyl- (1→6)-β-D-glucopyranoside (9), (6R,7E,9R)-9-hydroxy- 4,7-megastigma-dien-3-one-9-O- β-D-xylopyranosyl-(1→6)-β-D- glucopyranoside (10), and quercetin 3-O-sambubioside (11) were isolated from the leaves of Eucommia ulmoides Oliv. The structure of compound 1 was determined by extensive spectroscopic analysis, and its absolute configuration was determined by CD experiments and a computational method. Compounds 3, 4, 7-10 were isolated from this plant for the first time. Compounds 3 and 4 showed inhibition to PTPIB activities, with IC50 values of 0.69 and 3.98 μM, respectively. © 2012 by the authors.