Medicinal flowers. XIV. New acylated oleanane-type triterpene oligoglycosides with antiallergic activity from flower buds of chinese tea plant (Camellia sinensis).

The methanolic extract from the flower buds of Chinese tea plant (Camellia sinensis (L.) O. KUNTZE) was found to inhibit release of beta-hexosaminidase from RBL-2H3 cells. From the methanolic extract, six new acylated oleanane-type triterpene oligoglycosides, floratheasaponins D-I, were isolated together with 21 known compounds including floratheasaponins A-C. The chemical structures of floratheasaponins D-I were elucidated on the basis of chemical and physicochemical evidence. The principal constituents, floratheasaponins A-F, were found to show the inhibitory activity on the release of beta-hexosaminidase from RBL-2H3 cells.