Inhibitory effect of chalcones and their derivatives from Glycyrrhiza inflata on protein tyrosine phosphatase 1B.

Compounds (1-6) isolated from the CH(2)Cl(2) extract of Glycyrrhiza inflata and semisynthetic licochalcone A derivatives (7-14) were evaluated for their protein tyrosine phosphatase 1B (PTP1B) inhibitory activities. Licochalcones A (4) and E (6), each with an allyl group at position 5 in the B ring exhibited significant inhibitory effects. Licochalcone A derivative 7, the most potent among the series, had an IC(50) value of 11.7+/-2.0 microM, ca. twofold better than that of licochalcone A (4).