Rhodanine as a Potent Scaffold for the Development of Broad-Spectrum Metallo-β-lactamase Inhibitors

A series of rhodanines was constructed, their Z-configuration was confirmed by small molecule X-ray crystal structures, and their activity against metallo-β-lactamases (MβLs) was measured. The obtained 26 molecules and a thioenolate specifically inhibited the MβL L1 with an IC50 range of 0.02–1.7 μM, and compounds 2h–m exhibited broad-spectrum inhibition of the MβLs NDM-1, VIM-2, ImiS, and L1 with IC50 values <16 μM. All inhibitors increased the antimicrobial effect of cefazolin against E. coli cells expressing L1, resulting in a 2–8-fold reduction in MIC. Docking studies suggested that the nitro (NDM-1, CphA, and L1) or carboxyl group (VIM-2) of 2l coordinates one or two Zn(II) ions, while the N-phenyl group of the inhibitor enhances its hydrophobic interaction with MβLs. These studies demonstrate that the diaryl-substituted rhodanines are good scaffolds for the design of future broad-spectrum inhibitors of MβLs.