Synthesis of Urea‐Containing Derivatives and their Application as Potential Anti‐Methicillin‐Resistant Staphylococcus Aureus Agents

We describe the synthesis and activity against methicillin‐resistant Staphylococcus aureus (MRSA) of a collection of urea‐containing amides. The approach considered the ureido group as a bioisoster of known FabI inhibitors. NMR characterization and density functional theory studies demonstrated the presence of s‐cis and s‐trans rotamers in the N‐benzyl examples (series 2). Preliminary screening showed the ability of series 1 and 3 (N‐aryl and N‐arilpiperidone derivatives, respectively) to inhibit the bacterial growth of two MRSA strains (a clinical isolate and ATCC 33591). Compound 3b inhibited 50% of the clinical strain and 34% of the ATCC. Subsequent biological assays let us determine the IC50 values of the most active ureas in both strains, standing out compounds 1a (45.8 ± 2.3 μM) and 3b (43.6 ± 2.0 μM). Finally, molecular docking suggests FabI as a possible molecular target for the designed compounds.