Synthesis and in vitro chemical and enzymatic stability of glycosyl 3’ – azido – 3’ – deoxythymidine derivatives as potential anti-HIV agents

New glycosyl derivatives of 39-azido-39-deoxythymidine (AZT) (1 and 2) were synthesized in order to improve AZT retention in the
blood and to guarantee its sustained release, overcoming the necessity of multiple drug administrations. The esters synthesized (1 and 2)
link AZT, by a succinyl linker, to the C-3 position of glucose and to C-6 of galactose. Furthermore, the chemical and enzymatic stabilities
of esters 1 and 2 were evaluated in order to determine both their stability in aqueous medium and their feasibility to undergo enzymatic
cleavage by esterase to regenerate the original drug. The pharmacokinetic profiles of esters 1 and 2, obtained after systemic
administration, showed an interesting controlled release, in particular for ester 2, compared to the pharmacokinetic profile of AZT.