Synthesis, Decomposition Pathways and “In Vitro” Evaluation of Bioreversible Phosphotriesters of Azt

Abstract

The synthesis, pharmacokinetic data and biological evaluation of a series of phosphotriesters containing S-acyl-2-thioethyl groups as enzyme-labile phosphate protecting groups and AZT as a model are described. A comparison of pharmacokinetic data and “in vitro” experiments show that such bioreversible phosphotriesters of AZT are able to cross cell membranes and deliver the corresponding nucleoside monophosphate inside the cell. Moreover, kinetic data show that modification of the protecting groups can allow to modulate both the extracellular stability of the parent compond and the delivery of nucleoside monophosphate inside the cell.