Structures of new acylated oleanene-type triterpene oligoglycosides, theasaponins E1 and E2, from the seeds of tea plant, Camellia sinensis (L.) O. Kuntze.

摘要

Two new acylated oleanene-type triterpene oligoglycosides, theasaponins E1 and E2, were isolated from the seeds of tea plant [Camellia sinensis (L.) O. Kuntze]. The structures of theasaponins E1 and E2 were elucidated on the basis of chemical and physicochemical evidence to be expressed as 21-O-angeloyl-22-O-acetyltheasapogenol E 3-O-[beta-D-galactopyranosyl(1-->2])[beta-D-xylopyranosyl(1-->2)-alpha-L - arabinopyranosyl (1-->3)]-beta-D-glucopyranosiduronic acid and 21-O-angeloyl-28-O-acetyltheasapogenol E 3-O-[beta-D-galactopyranosyl(1-->2)][beta-D-xylopyranosyl (1-->2)-alpha-L-arabinopyranosyl (1-->3)-beta-D-glucopyranosiduronic acid, respectively. Theasaponin E1 was found to show antisweet activity.