Bioactive saponins and glycosides. XXVIII. New triterpene saponins, foliatheasaponins I, II, III, IV, and V, from Tencha (the leaves of Camellia sinensis)

New triterpene saponins, foliatheasaponins I-V, were isolated from the methanolic extract of Tencha the leaves of Camellia sinensis (L.) O. KUNTZE (Theaceae)]. The chemical structures of these new saponins were elucidated on the basis of chemical and physicochemical evidence. Among the new saponins, foliatheasaponins II and III, were found to inhibit release of beta-hexosaminidase, as a marker of antigen-induced degranulation, in RBL-2H3 cells.