The pyrimidine thymidine consists of thymine combined with deoxyribose. Prior to polymerization into DNA, thymidine must be phosphorylated at the hydroxyl group on carbon 5 of the ribose moiety. 5'-Deoxythymidine is a form of thymidine in which the hydroxyl group on carbon 5 of ribose has been replaced with hydrogen. As a result, this compound cannot be phosphorylated and used by DNA polymerase in the synthesis of DNA. 5'-Deoxythymidine is readily imported by cellular nucleoside importers and competitively inhibits the influx of thymidine. It demonstrates antibacterial activity against B. subtilis and S. aureus.
