Molecular characteristics and prediction of the reactive properties of N-chlorotaurine analogs.

A number of molecular characteristics for the N-chlorotaurine structural analogs, amino acid chloramines, and related compounds have been computed by the ab initio B3LYP/6-31G method. In particular, the characteristics were the Mulliken atomic charges for the chloramine part and adjacent atoms. The quantitative measure of the capabilities of the chloramines to react with the methionine sulfide group or the sulfhydryl group of reduced glutathione was their reaction rate constants. The constants available in the literature and those found in our experiments have been depicted with an exponential equation of multiple correlations. In the case of the reaction with methionine, the high determination coefficient ( R) was obtained with five independent variables, which were the charges of available chlorine, nitrogen, and carbon bonded with nitrogen, the bond length between the nitrogen and carbon atoms, and the molecular weight. The equation was used to predict the rate constant values for the reactions between methionine and compounds containing available chlorine. The prediction showed that the structural analogs of N-chlorotaurine bearing two methyl groups at β-carbon of taurine are remarkable for the low value of the rate constant under discussion. [ABSTRACT FROM AUTHOR]