Novel bioactive azo-azomethine based Cu (II), Co (II) and Ni(II) complexes, structural determination and biological activity

A novel bioactive azo-azomithine tridentate ligand N'-(E)-{2-hydroxy-3-methoxy-5-[(E)phenyldiazenyl] phenyl}methylidene]pyridine-3 carbohydrazide (HL) and its Cu(II), Co(II) and Ni(II) complexes were synthesized and their structure determined by elemental analysis, spectroscopic studies (FTIR, H-1 NMR, C-13 NMR, LC-MS, UV-vis, ESR, and powder XRD) and magnetic susceptibility measurements. The molar conductivity measurement proved that all the complexes are non-electrolytic in nature. On the basis of physicochemical and spectroscopic data, the octahedral geometry is assigned for all the metal complexes. The thermal decomposition curve indicated the existence of lattice water molecule. The binding studies of all the synthesized complexes against CT-DNA suggest that the intercalation binding mode. A DNA nuclease activity exhibited that all complexes cleaved pBR322 DNA in an efficient manner. Consequently, the cytotoxic activity of the compounds was screened against A-549 (lung carcinoma), MDA-MB 231 (breast carcinoma) and normal HEK293 (human embryonic kidney cells) cell lines using MTT assay. (C) 2019 Elsevier B.V. All rights reserved.