Design and Biological Evaluation of Cephalosporin Based Metallo-β-lactamase (MBL) Inhibitors

Background: Prevalence of microbial resistance due to Metallo-beta-lactamase (MBL) enzyme pose a serious threat to human life. MBLs depend on active site zinc for their hydrolytic activity; hence, the investigation of zinc chelators emerged as an attractive strategy for the development of potent MBL inhibitors. Method: To prove that such chelators selectively target MBLs, in the present investigation, novel cephalosporins based MBL inhibitors (Cef-MBLi) were designed as a conjugate of cephalosporins with a potent zinc binder 8-thioquinoline (8-TQ). Result: Cef-MBLi showed site specific release of conjugate only in the presence of a Verona-integron encoded metallo-beta-lactamase 2 (VIM-2) bacterial enzyme through hydrolytic cleavage mechanism. A total of 6 (4a-e and 6f) New Chemical Entities (NCE's) were prepared, characterized and subjected for in vitro study. Conclusion: Among tested NCE's, 4c showed potent MBL inhibitory activity against the VIM-2 enzyme.