Synthesis and evaluation of novel amidate prodrugs of PMEA and PMPA

Some novel amidate prodrugs of PMEA and PMPA have been synthesised and tested in vitro for their biological activity. Compound 5 in particular showed greatly enhanced antiviral potency compared with the parent nucleotide analogue. In vitro enzymatic studies and structure–activity relationships indicate that the degradation mechanism of such prodrugs may be the same as that described for the phosphoramidate triesters of nucleotide analogues.