Floratheasaponins A-C, acylated oleanane-type triterpene oligoglycosides with anti-hyperlipidemic activities from flowers of the tea plant (Camellia sinensis)

The methanolic extract and its n-butanol-soluble fraction from the flowers of the tea plant (Camellia sinensis) were found to suppress serum triglyceride elevation in olive oil-treated mice. From the it -butanol-soluble fraction, three new acylated oleanane-type triterpene oligoglycosides, floratheasaponins A-C (1-3), were isolated together with several flavonol glycosides and catechins. The structures of 1-3 were elucidated on the basis of chemical and physicochemical evidence as 21-O-angeloyl-22-O-acetyltlicasa-pogenol B 3-O-[beta-D-galactopyranosyl(1 -> 2)beta-D-xylopyranosyl(1 -> 2)-alpha-L-arabinopyranosyl(1 -> 3)]-beta-D-glucopyranosiduronic acid, 21,22-di-O-angeloyl-R-1-barrigenol 3-O-[beta-D-galactopyranosyl(1 -> 2)[beta-D-xylopyranosyl-(1 -> 2)-(alpha-L-arabinopyranosyl(1 -> 3)]beta-D-glueopyranosiduronic acid, and 21-O-angeloyl-22-O-2-metliylbutyryl-R-1-barrigenol 3-O-[beta-D-galactopyranosyl(1 -> 2)][beta-D-xylopyranosyl(1 -> 2)-alpha-L-arabinopyrano(1 -> 3) -beta-D-glueopyranosiduronic acid, respectively. Floratheasaponins (1-3) showed inhibitory effects on serum triglyceride elevation, with their activities being more potent than those of theasaponins E-1 (4) and E-2 (5) obtained previously from the seeds of C. sinensis.