Abstract: The free radical scavenging activities of genistein and its lactocides were assessed by using three methods, namely the anti-DPPH free radical, Fenton reaction with 1,10-phenanthroline-Fe2+ spectrophotometry and pyrogallol autoxidation assays. The results showed that the abilities of genistein and its lactosides in scavenging DPPH· and ·OH radicals are in the order of genistein 7,4′di-O-β-lactoside > genistein 4′-O-β-lactoside > genistein 7-O-β-lactoside > genistein. In contrast, genistein is effective in scavenging O2· than its lactosides at low concentration. Furthermore, the other two genistein lactosides have negative effects on inhibiting autoxidation rate of pyrogallol except for genistein 7-O-β-lactoside. In general, the inhibiting rates to samples decrease with the concentration increase.

Key words: genistein, lactosides, free radical scavenging activity