Chemical constituents of the aerial parts of Glycyrrhiza uralensis and their inhibitory activities against PTP1B and α-glucosidase

In the present study, a total of 11 compounds were isolated from the aerial parts of Glycyrrhiza uralensis, including two new compounds, glycyuralin Q (1) and glycyuralin R (2), and nine known compounds, including licoriphenone (3), orobol (4), trifoliol (5), 7,2′,4′-trihydroxy-5-methoxy-3-arylcoumarin (6), 11-hydroxy-9(Z),12(Z)-octadecadienoic acid (7), 11-hydroxy-9(E),12(E)-octadecadienoic acid (8), licoricone (9), glycyrin (10), and 2′-hydroxyformononetin (11). Structures of the new compounds were identified by 1D, 2D NMR and HR-MS data analyses. Compounds 1, 2 and 10 showed potent inhibitory activities against PTP1B, with IC₅₀ values of 1.43, 4.71 and 3.79 μM, respectively. Compounds 2, 4 and 10 inhibited α-glucosidase with IC₅₀ values of 13.61, 11.13 and 17.48 μM, respectively.