Determination of isoprenyl and lavandulyl positions of flavonoids fromSophora flavescens by NMR experiment.

All fifteen flavonoids (1 approximately 15) have been isolated from the roots ofSophora flavescens (Leguminosae) as active principles of the cytotoxic property toward human tumor cell lines such as A549, SK-OV-3, SK-Mel-2, XF498 and HCT15,in vitro. By means of spectral analyses, particularly by the aid of various two dimensional NMR experiments, all(1)H-NMR and(13)C-NMR signals of1 approximately 15 were completely assigned, and thus the structures of1 approximately 15 were established unambiguously.