Antimutagenic activity of 8-hydroxyisoflavones and 6-hydroxydaidzein from soybean miso.

The antimutagenic activity of four isoflavones isolated from soybean miso toward three kinds of mutagens, AF-2, MNNG, and Trp-P-1, was evaluated by the Ames test. 8-Hydroxyisoflavones had greater suppressive potency than that of daidzein, and 6-hydroxydaidzein had almost the same activity as daidzein. These results indicated the number of hydroxy and methoxy groups and the position of these functional groups were important for antimutagenic activity.