Structures of New Acylated Oleanene-Type triterpene Oligoglycosides, Theasaponins E₁ and E₂. from the Seeds of Tea Plant, Camellia sinensis (L.) O. KUNTZE

Abstract

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