(1)Yu Ko M Sagesaka, Terumi U, Naoharu W, etal. A new glucuronide saponin from tea leaves. biosci biotech biochem, 1994, 58(11): 2035-2040 (2)Yi Lu, Tasuya U, et al. Triterpenoid saponins from the root of tea plant. Phytochem, 2000(35): 940-946 (3)Chendel R S, etal. Triterpenoid saponins and sapogenins. Phytochem, 1980(19): 1889-1980