2-(glucosylthio)ethyl groups as potential biolabile phosphate-protecting groups of mononucleotides

The in vitro anti-HIV effects and the stability studies of mononucleoside phosphotriester derivatives 1-3 of 3'-azido-3'-deoxythymidine (AZT) containing 2-(glucosylthio)ethyl moieties as potential biolabile phosphate-protecting groups are reported.;The results of the anti-HIV evaluation demonstrate that the described compounds act via the release of the free nucleoside analogue and cannot be considered as mononucleotide prodrugs (pronucleotides). These data can be related to the lack of substrate affinity of these derivatives towards target-enzymes as corroborated by decomposition studies in various media and experiments with a purified beta-D glucosidase.