A comprehensive study on synthesis and crystal structures of Cu(II) and Ni(II) complexes: In vitro and in silico evaluation of biomolecular interactions, antiproliferative activities and molecular docking

•A distorted octahedral copper(II) and nickel(II) complexes containing 2,2′:6′,2″-terpyridine was synthesized and characterized.•Synthesized complexes show good CT-DNA and BSA binding activity.•Antiproliferative activity on human breast cancer (MCF-7) and lung cancer (A549 and H1299) cell lines of the synthesized complexes are comparable with cisplatin.•Molecular docking analysis was carried out against ALK (anaplastic lymphoma kinase), Hsp90 (Heat shock protein 90), EGFR (epidermal growth factor receptor), BHb (bovine hemoglobin), HER2 (human epidermal growth factor receptor 2), and B-DNA. Cu(II) and Ni(II) complexes, [Cu(NNN)2](NO3)2 (1) and [Ni(NNN)2](NO3)2 (2) (NNN-donor ligand: 2,2′:6′,2″-terpyridine), have been synthesized and characterized by electronic absorption spectroscopy, CHN analysis, FTIR, ESI-MS and X-ray crystallography techniques. Interaction of the complexes 1 and 2 with biomolecules (calf thymus DNA (CT-DNA) and bovine serum albumin (BSA)) has been investigated by electronic absorption and fluorescence spectroscopy. The results show that the complexes 1 and 2 can bind to CT-DNA via a moderate intercalation mode. Moreover, the fluorescence quenching mechanism between the complexes 1 and 2 and BSA is a static quenching process. The antiproliferative activities of the complexes 1 and 2 against human breast cancer (MCF-7) and lung cancer (A549 and H1299) cell lines were investigated. The complex 1 was found to have promising antiproliferative activity in selected cell line, with lower IC50 values than cisplatin. Molecular docking studies conducted across the complexes 1 and 2 have provided their potential as prospective chemotherapeutic agents against tumors. The complexes 1 and 2 demonstrated spontaneous binding with targets including anaplastic lymphoma kinase (ALK), heat shock protein 90 (Hsp90), epidermal growth factor receptor (EGFR), bovine hemoglobin (BHb), human epidermal growth factor receptor 2 (HER2), and B-DNA. These interactions are primarily driven by van der Waals forces and π-π interactions. Determining binding constants and the multiplicity of binding sites enhances understanding of these molecular interactions. [Display omitted]