| Abstract: | The radicals produced by reactions of hydroxyl radicals with amino acids in aqueous solutions have been investigated. Hydroxyl radicals were formed by U.V.-photolysis of hydrogen peroxide and the short-lived amino acid radicals were spin-trapped by tert-nitrosobutane and identified by electron spin resonance spectroscopy. Nineteen amino acids were studied, and several radicals were identified which have not been observed previously by other methods. Only side-chain radicals were identified for alanine, threonine, aspartic acid, asparagine, lysine, phenylalanine, tyrosine, proline and hydroxyproline; whereas for glycine the C(2) carbon radical was spin-trapped. Both C(2) carbon radicals and side-chain radicals were assigned to valine, leucine, isoleucine, serine, glutamic acid, glutamine, arginine and methionine. |
