1H Nmr Spectra of Penylated Flavonoids and Pyranoflavonoids

Abstract

1 H Nmr examination of prenylated flavonoids has shown that the presence of the prenyl group at C-3, C-6, or C-8 position of flavone can be deduced from the chemical shift of methylene protons of prenyl group measured in acetone-d 6 . The chemical shifts of olefinic proton on pyran ring and A ring proton can be used to distinguish between linear type pyranoflavone and angular type pyranoflavone. The application of this 1 H nmr method to the identification of Atalantia flavone and Artocarpus flavones is discussed