Structural determination of quercusides A and B, new flavonoid glucosides from Quercus incana, by 1D and 2D NMR spectroscopy

Quercusides A and B, new flavonoid glucosides have been isolated from the chloroform soluble fractions of Quercus incana. Their structures were assigned from 1H and 13C nuclear magnetic resonance spectra, distortionless enhancement by polarization transfer (DEPT) and by correlation spectroscopy, heteronuclear multiple quantum correlation (HMQC) and heteronuclear multiple bond correlation (HMBC) experiments. Lupeol, β-sitosterol and ursolic acid have also been reported from this species. Copyright © 2009 John Wiley & Sons, Ltd.