Dinuclear copper(II) complexes bridged with acetate and nitrate anions: Study of protein binding and in-vitro anticancer activity

Abstract

Two dinuclear copper(Ⅱ) complexes [Cu(L)(μ-AcO)2]2·H2O (1) and [Cu(L)(bpy)(μ-NO3)]2. (ClO4)2 (2) were synthesized with the ligand L = N-(3-pyridyl)-1,8-naphthalimide (where, OAc = Acetate, bpy = 2,2′-bipyridine). The complexes were characterized with FT-IR, UV–vis, fluorescence, EPR, and single crystal X-ray diffraction technique. Complex 1 contains two copper(Ⅱ) units bridged by four acetate ions via oxygen atoms having distorted square pyramidal geometry around both the copper(Ⅱ) centers. Complex 2 consists of two copper(Ⅱ) centers with two bridging nitrates via oxygen atoms in a distorted square pyramidal environment. The complexes 1 and 2 efficiently bind to BSA (bovine serum albumin) showing a dynamic quenching mechanism. The in-vitro anticancer activity have been investigated against HeLa cell lines using MTT assay. Complex 1 is two times more active than cisplatin under the same experimental conditions, whereas complex 2 is twelve times more active.