EPR of γ-irradiated L-glutamine, glycyl-L-glutamine and N-glycyl-L-valine

gamma-irradiated powders of L-glutamine, glycyl-L-glutamine and N-glycyl-L-valine were investigated at room temperature and 150K by electron paramagnetic resonance (EPR). The spectra were found to be temperature independent. The g-values and hyperfine coupling constants of the unpaired electrons with the environmental protons and the N-14 nucleus were determined. The species were found to be stable at room temperature for more than six months. The unirradiated samples were found to display no EPR signal.