FLAVONOL GLYCOSIDES FROM THE LEAVES OF GINKGO BILOBA

AIM　Isolation and structural elucidation of the constituents from leaves of Ginkgo biloba. METHODS　To isolate chemical constituents, solvent extraction together with column chromatography was used. IR, UV, MS and NMR spectra were employed for structural identification. RESULTS　Eight flavonol glycosides were isolated. They were elucidated as quercetin-3-O-β-D-glucoside(1), kaempferol-3-O-β-D-glucoside(2), rutin(3), kaempferol-3-O-β-D-rutinoside(4), isorhamnetin-3-O-β-D-rutinoside(5), quercetin-3-O-β-D-glucosyl(1-2)-α-L-rhamnoside(6), kaempferol-3-O-β-D-glucosyl(1-2)-α-L-rhamnoside(7) and isorhamnetin-3-O-β-D-glucosyl(1-2)-α-L-rhamnoside(8). CONCLUSION　Compound 8 was shown to be a new compound.