The clinical effectiveness of the important β-lactam class of antibiotics is under threat by the emergence of resistance, mostly due to the production of acquired serine- (SBL) and metallo-β-lactamase (MBL) enzymes. To address this resistance issue, multiple β-lactam/β-lactamase inhibitor combinations have been successfully introduced into the clinic over the past several decades. However, all of those combinations contain SBL inhibitors and, as yet, there are no MBL inhibitors in clinical use. Consequently, there exists an unaddressed yet growing healthcare problem due to the rise in recent years of highly resistant strains which produce New Delhi metallo (NDM)-type metallo-carbapenemases. Previously, we reported the characterization of an advanced MBL inhibitor lead compound, ANT431. Herein, we discuss the completion of a lead optimization campaign culminating in the discovery of the preclinical candidate ANT2681, a potent NDM inhibitor with strong potential for clinical development.

Quinazolines and 1,2,4-triazoles are important class of nitrogen containing heterocyclic compounds having immense biological importance. From the literature review, pharmacokinetic properties of a drug can be modified or enhanced by building a triazole moiety into a compound like quinazoline. Therefore, the study of new hybrid systems which combines triazole system with quinazoline is still seemed warranted. In the present study, a sequence of novel 1,2,4-triazole derivatives containing quinazolinyl moiety were designed, synthesized and screened for their in vitro anticancer activity. Thirteen new hybrids are synthesized from readily accessible 5-bromoanthranilic acid. All the hybrid compounds were well explicated by IR, 1H, 13C NMR, and mass spectral data. Out of 13, some of the compounds manifested moderate to good antiproliferative activity against two cancer cell lines (HepG2 and MCF7). Remarkably, compounds 8A, 16H and 16K displayed potent activity (14- 49 µM) on both HepG2 (liver carcinoma) and MCF-7 (breast cancer) cell lines whereas compounds 8B, 8F, 16L, and 15 displayed substantial activity against HepG2 cancer cell line (34-65 µM). Synthetic approach described here is very simple and can be used for the syntheses of related compounds library which is useful for the exploration of further biological activities and is currently underway in our laboratory