Flavonol glycosides of Warburgia ugandensis leaves

Four new flavonol glycosides: kaempferide 3-O-β-xylosyl (1→2)-β-glucoside, kaempferol 3-O-α-rhamnoside-7,4′-di-O-β-galactoside, kaempferol 3,7,4′-tri-O-β-glucoside and quercetin 3-O-[α-rhamnosyl (1→6)] [β-glucosyl (1→2)]-β-glucoside-7-O-α-rhamnoside, were characterized from a methanolic leaf extract of Warburgia ugandensis. The known flavonols: kaempferol, kaempferol 3-rhamnoside, kaempferol 3-rutinoside, myricetin, quercetin 3-rhamnoside, kaempferol 3-arabinoside, quercetin 3-glucoside, quercetin, kaempferol 3-rhamnoside-4′-galactoside, myricetin 3-galactoside and kaempferol 3-glucoside were also isolated. Structures were established by spectroscopic and chemical methods and by comparison with authentic samples.