title: E.S.R. of spin-trapped radicals in gamma-irradiated polycrystalline amino acids. Chromatographic separation of radicals.
abstract: The free radicals produced by gamma-radiolysis of polycrystalline amino acids (L-valine, L-leucine, L-isoleucine and L-proline) at room temperature in the absence of air were investigated by spin trapping with 2-methyl-2-nitrosopropane (MNP). The spin adducts produced by dissolving the irradiated solids in aqueous MNP solutions were separated by high-performance liquid chromatography and then identified by e.s.r. Deamination (ring-opening reaction for L-proline) was observed for all amino acid. For L-valine and L-leucine, H-abstraction from the tertiary carbon in the side chains occurred. For isoleucine, H-abstractions from the alpha-carbon of the amino acid and from a non-terminal carbon in the side chain were found.
mesh_terms: D000596:Amino Acids / Q000528:radiation effects*; D002851:Chromatography, High Pressure Liquid; D003641:Deamination; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D005720:Gamma Rays; D007532:Isoleucine / Q000528:radiation effects; D007930:Leucine / Q000528:radiation effects; D011392:Proline / Q000528:radiation effects; D014633:Valine / Q000528:radiation effects
chemical_list: D000596:Amino Acids; D005609:Free Radicals; D007532:Isoleucine; D011392:Proline; D007930:Leucine; D014633:Valine