We isolated from soybean miso 8-hydroxyglycitein and 6-hydroxydaidzein as DPPH-radical scavengers, and elucidated their chemical structures by mass spectrometric, and 1H- and 13C-NMR spectrosopic analyses. These compounds showed DPPH-radical scavenging activity as high as that of α-tocopherol, 8-hydroxygenistein and 8-hydroxydaidzein. This is the first report of the isolation of 8-hydroxyglycitein from a natural source.
