Exploring the mechanism of conversion of monosulfiram into disulfiram

Abstract

Monosulfiram is a drug used topically in the treatment of scabies. Upon its application it shows similar effects as seen in case of disulfiram, a drug used in alcohol aversion therapy. Previous reports have concluded a light induced conversion of monosulfiram (MS) into disulfiram (DS). In the present study a computational approach has been involved to investigate the mechanism of this conversion. Structures have been optimized using MP2 and DFT approach. Insights on their reactivities have been assessed through conceptual DFT. Time-dependent DFT investigation has been undertaken to obtain excitation energies for singlet and triplet states. Bond dissociation energies of both molecules have also been obtained and analyzed. It has been found that conversion of MS into DS occurs in both thermal and photochemical situations.