Chemical constituents of Callicarpa nudiflora and their anti-platelet aggregation activity.

Two new triterpenoids, 2α,3α,19α,23-tetrahydroxyurs-12,20(30)-dien-28-oic acid (1) and 2α,3α,19α-trihydroxyurs-12-en-28-oic acid-28-O-β-D-xylopyranosyl (1→2)-β-D-glucopyranoside (2), and a new acylated flavone glycoside, luteolin 3'-O-(6″-E-caffeoyl)-β-D-glucopyranoside (3), together with three known compounds (4-6), were isolated from the leaves of Callicarpa nudiflora Hook. Their structures were elucidated on the basis of spectroscopic data and chemical methods. Anti-platelet aggregation activities of these compounds were evaluated in vitro. Compounds 1 and 2 showed inhibitory effects on ADP-induced platelet aggregation with EC50 values of 9.48 μM and 25.31 μM, respectively.