Two new triterpenoid saponins isolated from Polygala japonica

Bioassay guided investigation of whole parts of Polygala japonica afforded two new triterpenoid saponins, characterized as 3-O-beta-D-glucopyranosyl medicagenic acid 28-O-{beta-D-xylopyranosyl(1-->4)-[beta-D-apiofuranosyl(1-->3)]-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl} ester (1), 3-O-beta-D-glucopyranosyl 2-oxo-olean-12-en-23, 28-dioic acid 28-O-{beta-D-xylopyranosyl(1-->4)-[beta-D-apiofuranosyl(1-->3)]-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl} ester (2), together with four known triterpenoid saponins (3-6). Their structures were elucidated by spectroscopic and chemical methods. Saponins 3, 4 and 5 showed significant anti-inflammation effects on carrageenan-induced acute paw edema in mouse.