1,2-Dipolar addition model for the cytoprotective activity of selected alpha,beta-unsaturated compounds with C = O functionality: an ab initio study

The mechanism of the addition of a nucleophile (an alkylthiol group) to a d ouble bond of alpha,beta -unsaturated systems in the gas phase was explored . In this study, intermediates of the reaction were also investigated using ab initio calculations (RHF/6-31G* and MP2/6-31 +G*). Our results indicate that direct dipolar attack of the S-H group of an alkylthiol on the C=C do uble bond is a reasonable reaction path. The present results represent, the refore, additional support for our hypothesis. This suggests that the mecha nism of cytoprotection might be mediated, at least in part, by a reaction b etween the olefinic acceptor and the sulfhydryl-containing groups of the mu cosa. (C) 2001 Elsevier Science B.V. All rights reserved.