EPR study of free radicals in amino acid derivatives gamma-irradiated at 300 K

Electron paramagnetic resonance spectroscopy has been used to study the free radicals in N-acetyl-L-leucine methyl ester and N-acetyl-L-glutamic acid powders gamma-irradiated at room temperature (300 K). It has been found that gamma-irradiation produces the (CH(3))(2)GCH(2)CH(NHCOCH(3))COOCH(3) radical in the first and the HOOCCH(2)CH(2)C(NHCOCH(3))COOH radical in the second compounds. The g values of the radicals and the hyperfine coupling constants of the free electron with the environmental methyl, methylene protons and (14)N nucleus have been determined. Both free radicals are found to be stable without almost intensity diminution for five months at room temperature. The results have been found to be in good agreement with the existing literature data.