EPR Spin-Trapping Studies of the Hydroxyl Radical Scavenging Activity of Carnosine and Related Dipeptides

Wendy K.M. Chan, Eric A. Decker, Jin B. Lee, David A. ButterfieId

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121 Scopus citations


The electron paramagnetic resonance technique of spin trapping was employed to study the interaction of hydroxyl radicals with carnosine and related His-containing dipeptides. His and His-containing dipeptides were able to quench 49.1-94.9% of hydroxyl radicals produced by Fe2+ and H2O2. The hydroxyl radical scavenging activity of dipeptides was in the order β-Ala < γ-aminobutyric acid (GABA) < Gly < His < homocarnosine < carnosine < Gly-His. Nonhydroxyl radicals spin trapped by 5,5-dimethylpyrroline N-oxide with similar splitting constants of αN= 15.6 G and αHβ= 18.8 G were detected from homocarnosine, carnosine, and Gly-His in the presence of the hydroxyl radical generation system. The ability of dipeptides and amino acids to inhibit hydroxyl radical catalyzed oxidation of phosphatidylcholine liposomes was in the order β-Ala < Gly = GABA < Gly-His < His < homocarnosine < carnosine. These data suggest that the hydroxyl radical scavenging and antioxidant activities of the dipeptides are related to the presence of the peptide bond and the amino acid composition of the dipeptides.

Original languageEnglish
Pages (from-to)1407-1410
Number of pages4
JournalJournal of Agricultural and Food Chemistry
Issue number7
StatePublished - Jul 1 1994


  • Hydroxyl radical
  • antioxidant
  • carnosine
  • electron paramagnetic resonance
  • homocarnosine

ASJC Scopus subject areas

  • General Chemistry
  • General Agricultural and Biological Sciences


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