[Flavonol glycosides from Lysimachia clethroides].

Eleven flavonol glycosides were isolated from the ethanol extract of Lysimachia clethroides by a combination of various chromatographic techniques including column chromatography over silica gel, Sephadex LH-20, and reversed-phase HPLC. Their structures were identified as astragalin (1), isoquercitrin (2), isorhamnetin-3-O-β-D-glucopyranoside (3), quercetin-3-O-β-D-6"-acetylglucopyranoside (4), quercetin-7-O-β-D-glucopyranoside (5), prunin (6), 2-hydroxynaringin-5-O-β-D-glucopyranoside (7), kaempferol-3-O-rutinonoside (8), kaempferol-3-O-robinobioside (9), rutin (10) and kaempferol-3,7-di-O-β-D-glucopyranoside (11). Among them, compounds 4, 7 and 11 were obtained from the Lysimachia genus for the first time, while compounds 3, 5 and 9 were firstly reported from this plant. In the preliminary assays, compounds 2, 6 and 8 possessed significant inhibition against aldose reduc- tase, with IC50 values of 2.69, 1.00, 1.80 μmol · L(-1), respectively; none of compounds 1-11 exhibited obvious cytotoxic activity (IC50 > 10 μmol · L(-1)).