Thymidylate synthase (TS, ThyA) catalyzes the reductive methylation of 2'-deoxyuridine 5'- monophosphate to 2'-deoxythymidine 5'-monophosphate, an essential precursor for DNA synthesis. A specific inhibition of this enzyme induces bacterial cell death. As a second round lead optimization design, new 1, 2-naphthalein derivatives have been synthesized and tested against a TS-based biolibrary, including human thymidylate synthase (hTS). ...