[The relatioship between decomposition of amino acid chloramines and their structures]

Rate constants of the decomposition of monoamine alpha-amino acid chloramine derivatives were determined by a spectrophotometeric method. Several amino acid chloramines with elevated stability have been found. These included n-chloroglycine, n-chlorovaline, n-chlorothreonine, and n-chloroisoleucine. Their molecular structures are characterized by some characteristic feature at the beta-position. In the case of glycine chloramine, carbon atom at this position is absent, and the chloramine derivatives of three other amino acids possess branched chains. Partial atomic charges of the electrostatic potential (Wang-Ford) for chloramines of alpha-amino acids were computed using the semiempirical quantum-mechanical method AM1. The chloramines with elevated stability have high positive sums of charges of three carbon atoms that are atoms at alpha- and beta-positions and a carboxyl group atom. High partial charge also was obtained for one carbon atom at the beta-position. These computational values may be employed for prediction of the stability of designed amino acid chloramines. One of the important predictions is that the highest atomic charges and stabilities are characteristics of the amino acid chloramines, in which all hydrogen atoms at the beta-position are replaced by carbon-hydrogen chains or hydroxyl groups.