Isoflavonoids in the roots of Thermopsis fabacea D.C. (Leguminosae).

Nine isoflavonoids (I-IX) were isolated from the roots of Thermopsis fabacea D. C. (Leguminosae). The methanol extract afforded formononetin (I) and daidzein (II), the ethereal extract afforded trifolirhizin (III), dl-maackiain (IV), genistein (V), and 7, 3'-dihydroxy-4'-methoxyisoflavone (VI), and the ethyl acetate extract afforded formononetin-7-O-β-D-glucoside (VII), daidzin (VIII), and genistin (IX). These compounds were identified by means of degradation, spectroscopic studies, and direct comparison with authentic samples.