Flavonol glycosides from the leaves of Embelia keniensis

Five new flavonol glycosides characterized as syringetin 3-O-α-rhamnoside-7-O-β-glucoside, syringetin 3-O-α-rhamnoside- 7,4 -di-O-β-glucoside, quercetin-7-O-β-galactosyl (1→3)-β- galactoside, myricetin 3-O-α-rhamnosyl (1 →4)-β-galactoside and myricetin 3-O-β-glucosyl (1→2)-β-glucoside-7-O-β-glucosyl-(1 →4)-α-rhamnoside have been isolated from a methanolic extract of Embelia keniensis leaves. Known flavonols isolated from the same extract in eluded myricetin, quercetin, kaempferol, myricetin 3-O-α-rhamnoside, myricetin3-O-β-glucoside, quercetin 3-O-α-rhamnoside, quercetin 3-O-β-glucoside, quercetin 3-O-β-xyloside, isorhamnetin 3-O-α-rhamnoside and myricetin 3-O-rutinoside. Their structures were established from extensive spectroscopic and chemical studies and by comparison with authentic samples.