Triterpenes from Acanthopanax sessiliflorus Fruits and their Antiplatelet Aggregation Activities

One new triterpenoid saponin and two lupane-derived triterpenes were isolated from Acanthopanax sessiliflorus fruits. The structures of the two new compounds were elucidated as 3- O-[(alpha- L-arabinopyranosyl)-(1 --> 2)]-[ beta- D-glucuronopyranosyl-6- O-methyl ester]-olean-12-ene-28-olic acid (1) and (1 R,11 alpha,22 alpha)-1,4-epoxy-11,22-hydroxy-3,4-secolupane-20(30)-ene-3,28-dioic acid (3) on the basis of spectral analysis, including MS, (1)H-NMR, (13)C-NMR, DEPT, HMBC, HMQC and NOESY. The structure of the other new natural product was elucidated as (1 R,11 alpha)-1,4-epoxy-11-hydroxy-3,4-secolupane-20(30)-ene-3,28-dioic acid (2). All these compounds showed antiplatelet aggregation activity on ADP-induced platelet aggregation.