QUANTUM MOLECULAR MODELING OF THE INTERACTION BETWEEN GUANINE AND ALKYLATING-AGENTS .1. SULFUR MUSTARD

Interaction between Guanine and the episulfonium form of Sulfur mustar d (HD) was studied using the ab initio LCAO-MO method at the HF/6-31G level. The alkylation mechanism on guanine-N7 was analyzed by using a supermolecular modeling. Our stereostructural results associated with the molecular electrostatic potentials and HOMO-LUMO properties, show that in vacuum the alkylation of the N7 of guanine by HD in the agress ive episulfonium form is a direct process without transition state and of which the pathway is determined.