1,1-Diphenyl-2-picrylhydrazyl radical-scavenging compounds from soybean miso and antiproliferative activity of isoflavones from soybean miso toward the cancer cell lines.

Guided by their DPPH radical-scavenging activity, nine compounds were isolated from soybean miso. Of these, 8-hydroxydaidzein, 8-hydroxygenistein and syringic acid had as high DPPH radical-scavenging activity as that of alpha-tocopherol. The antiproliferative activity of four of the isolated isoflavones toward three cancer cell lines was examined. 8-Hydroxygenistein showed the highest activity (IC50=5.2 microM) toward human promyelocytic leukemia cells (HL-60).