Astersedifolioside A-C, three new oleane-type saponins with antiproliferative activity

A phytochemical analysis of Aster sedifolius has led to the isolation of three novel triterpenoid saponins, based on an oleane-type skeleton and named astersedifolioside A (1), B (2) and C (3). On the basis of chemical, and 2D NMR and mass spectrometry data, the structures of the new compounds were elucidated as 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranosyl] echinocystic acid 28-[O-alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinopyranoside] (1), 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranosyl] echinocystic acid 28-[O-beta-D-xylopyranosyl (1-->4)-O-alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinopyranoside] (2) and 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl] echinocystic acid 28-[O-beta-D-xylopyranosyl (1-->4)-O-alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinopyranoside] (3). The isolated compounds showed antiproliferative effect in KiMol, a transformed thyroid cell line.