A New Ursane-Type Nor-Triterpenoid from the Leaves of Eucommia ulmoides Oliv.

摘要

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-α-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.