New flavonol oligoglycosides and polyacylated sucroses with inhibitory effects on aldose reductase and platelet aggregation from the flowers of Prunus mume

The methanolic extract from the fresh flowers of Prunus mume exhibited inhibitory effects against aldose reductase and platelet aggregation. From the methanolic extract, two new flavonol oligoglycosides, 2' '-O-acetylrutin and 2' '-O-acetyl-3'-O-methylrutin, and two new polyacylated sucroses, prunoses I and II, were isolated together with 11 known constituents. The structures of 2' '-O-acetylrutin, 2' '-O-acetyl-3'-O-methylrutin, and prunoses I and II were determined on the basis of chemical and physicochemical evidence as quercetin 3-O-alpha-L-rhamnopyranosyl(1-->6)-2' '-O-acetyl-beta-D-glucopyranoside, 3'-O-methylquercetin 3-O-alpha-L-rhamnopyranosyl(1-->6)-2' '-O-acetyl-beta-D-glucopyranoside, 1,4,3',4',6'-penta-O-acetyl-6-O-p-coumaroylsucrose, and 1,3',4',6'-tetra-O-acetyl-6-O-p-coumaroylsucrose, respectively. The flavonol glycosides and prunose I were found to inhibit aldose reductase, while prunoses I and II inhibited platelet aggregation induced by thrombin.