A new flavonol named 5,4'-dihydroxy-6,7-[(1''S,2''R)-1''-hydroxy-2''-(1-hydroxy-1-methylethyl)-furano]flavonol (1), together with eight known compounds (2-9), were isolated from the seeds of Psoralea corylifolia. Their chemical structures were elucidated on the basis of spectroscopic analyses. In addition, all compounds were firstly studied for their proliferation effects on osteoblastic-like UMR 106 cells. Results showed that compounds 1, 2, 5 and 8 possessed significant promoting effects on cell proliferation and increased osteoblastic cell numbers by 26.3%, 34.6%, 20.5% and 21.1% at concentrations of 10-8 M, 10-8 M, 10-10 M and 10-10 M, respectively. These data indicated that flavonoids may be the main constituents accounting for the bone protective effects of the seeds of P. corylifolia.
Keywords: Leguminosae; Psoralea corylifolia; UMR 106 cells; flavonol; osteoporosis; proliferation effects.