A New Isoflayone Glycoside from the Stem Bark of Sophora japonica

A new isoflavone glycoside, 6-methoxy-7-hydroxy-4'-O-beta-D-glucosyl isoflavone, D-glucoside (10), along with nine known flavonoids, were isolated from the stem bark of Sophora japonica. The structures of these compounds were determined by analysis of spectroscopic data (1D -, 2D - NMR and HRMS). The inhibitory effects of all the isolated compounds on aldose reductase were evaluated in vitro. Among these compounds, daidzein (1), puerol A (4), and paratensein-7-O-glucoside (9) exhibited potent inhibitory effects, with IC50 values of 3.2, 6.4, and 1.9 mu M, respectively.