Electron paramagnetic resonance of some amino acid derivatives

VI SUMMARY In. this thesis, the powder of N-acetyl-L-arginine, Na-carbamyl-L-arginine, N- glycyl-L-leucine and N,N-dimethyl glycine HCI which are derivatives of the amino acids were irradiated by y-radiation. The EPR spectra of the y-irradiated powder samples were simulated and the EPR parameters of the radicals were determined. It is concluded from the determined EPR parameters, that the radiation damage center were ĞHCH2COOH, NHCHCH2, (CH3)2CCH2> (CH3)2NCHCOOH radicals respectively above order. Though g and A values of the radicals calculated at room temperature were found to be isotropic. The EPR spectrum of the y-irradiated N-acetyl-L-arginine powder consist of four lines, with intensity distribution 1:3:3:1. The hyperfme constants are similar to those for carboxyl and alkyl radicals. The EPR spectrum of the y- irradiated Na-carbamyl-L-arginine powder is thought to be results of abstraction hydrogen atom from the CH2 CH2NH group. The EPR spectrum of y-irradiated N- glycyl-L-leucine can easily thought of as consisting of five lines with an intensity.distribution 1:4:6:4:1. The simulation data for y-irradiated N,N-dimethyl glycine HCI powder indicate the unpaired electron spin interact with all protons in molecule. The hyperfme constants are similar to those for amine radicals.