title: Triterpene saponins with gastroprotective effects from tea seed (the seeds of Camellia sinensis).
abstract: Six new triterpene saponins, theasaponins A(1) (1), A(2) (2), A(3) (3), F(1) (4), F(2) (5), and F(3) (6), were isolated from the saponin fraction of the seeds of Camellia sinensis. The stereostructures of 1-6 were elucidated on the basis of chemical and physicochemical evidence. Theasaponin A(2) (2) showed an inhibitory effect on ethanol-induced gastric mucosal lesions in rats at a dose of 5.0 mg/kg, p.o., and its activity was more potent than that of omeplazole. Structure-activity relationships for theasaponins on ethanol-induced gastroprotective activities may be suggested as follows: (1) the 28-acetyl moiety enhances activity; (2) theasaponins having a 23-aldehyde group exhibit more potent activities than those with a 23-hydroxymethyl group or a 23-methoxycarbonyl group.
authors.affiliation: Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto 607-8412, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Morikawa
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.forename: Akifumi
authors.initials: A
authors.lastname: Nagatomo
authors.forename: Hisashi
authors.initials: H
authors.lastname: Matsuda
authors.forename: Xian
authors.initials: X
authors.lastname: Li
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yoshikawa
mesh_terms: D000818:Animals; D028241:Camellia sinensis / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry*; D051381:Rats; D012503:Saponins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D012639:Seeds / Q000737:chemistry; D013276:Stomach Ulcer / Q000188:drug therapy / Q000209:etiology / Q000517:prevention & control; D013329:Structure-Activity Relationship; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D012503:Saponins; D014315:Triterpenes