Evaluation of DNA binding, DNA cleavage, protein binding and in vitro cytotoxic activities of bivalent transition metal hydrazone complexes

Divalent Co, Ni and Cu hydrazone complexes containing [N′-(phenyl(pyridine-2-yl)methylidene) benzohydrazide] ligand were synthesised and characterised. Interactions of these complexes with DNA revealed an intercalative mode of binding between them. Further, all the hydrazone chelates showed moderate ability to cleave pUC19 DNA. Synchronous fluorescence spectra proved that the interaction of metal complexes with bovine serum albumin (BSA) resulted in a conformational change of the latter. Assay on the cytotoxicity of the above complexes against HeLa tumor cells and NIH 3T3 normal cells revealed that the complexes are toxic only against tumor cells but not to normal cells. In all the biological assays, the complex with copper ion as the metal center showed enhanced activities than the other two.

Graphical abstractSynthesis, structural elucidation and interaction with DNA, protein, cytotoxicity studies were carried out on biologically important transition metal hydrazone complexes.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Synthesis of new transition metal hydrazone complexes with octahedral geometry. ► All the new complexes showed significant interaction with both DNA and protein. ► Cytotoxicity results proved their efficacy against HeLa tumor cells.