α-Glucosidase inhibitory constituents from Acanthopanax senticosus harm leaves.

A new triterpene glycoside, 3-O-[(α-L-rhamnopyranosyl)(1→2)]-[β-D-glucuronopyranosyl-6-O-methyl ester]-olean-12-ene-28-olic acid (1) and a new indole alkaloid, 5-methoxy-2-oxoindolin-3-acetic acid methyl ester (5) were isolated from the leaves of Acanthopanax senticosus Harms along with six known compounds. The structures of the new compounds were determined by means of 2D-NMR experiments and chemical methods. All the isolated compounds were evaluated for their glycosidase inhibition activities and compound 6 showed significant α-glucosidase inhibition activity.