Studies on 2', 3'-Dideoxy-2', 3'-didehydropyrimidine Nucleosides. II. : N₄-Benzoyl-2', 3'-dideoxy-2', 3'-didehydrocytidine as a Prodrug of 2', 3'-Dideoxy-2', 3'-didehydrocytidine (DDCN)

Abstract

N₄-Benzoyl-2', 3'-dideoxy-2', 3'-didehydrocytidine (Bz-DDCN) was synthesized as a novel prodrug of 2', 3'-dideoxy-2', 3'-didehydrocytidine (DDCN), which is a reverse transcriptase inhibitor and is considered to be a potential antiacquired immunodeficiency syndrome agent. Chemical and enzymatic regeneration of DDCN from the prodrug has been investigated in both in vitro and in vivo experiments. Bz-DDCN regenerated DDCN under basic conditions (>pH 8), while cleavage of the N-glycosidic linkage and production of N₄-benzoylcytosine were observed under acidic conditions (>pH 6). DDCN was enzymatically regenerated from the prodrug in the presence of several enzyme preparations, including human plasma. DDCN and Bz-DDCN were intravenously administered to mice and the plasma concentrations of DDCN and the prodrug were measured. Though DDCN levels following direct DDCN administraiton decreased exponentially with a half-life of 14.5min, the plasma levels of DDCN following the prodrug administration were sustained above 2μM for over 3h.