We investigated scavenging of hydroxy radicals by lignan glucosides which are abundant in germinated sesame seeds. Hydroxy radicals were generated by the Fenton reaction and trapped with the nitrone trap 5, 5-dimethyl-1-pyrroline N-oxide. The resultant adduct was detected by electron paramagnetic resonance spectrometry. Five lignan glucosides tested could the scavenge hydroxy radicals. Four lignan glucosides at the concentrations 0.06 or 0.07μmol/ml scavenged 3.7×10-6 spin of hydroxy radicals. The scavenge activity depended upon the concentration.