Cu(II) complex containing p-Cl-isonitrosoacetophenone based on N 4-type Schiff base ligand was synthesized and characterized by elemental analysis, FTIR, H-1 NMR, (13) C NMR and UV-Visible. The crystal structure of the synthesized complex was determined by single crystal X-ray analysis. In the crystal structure, the intermolecular hydrogen bonds link the one dimensional polymers into a network structure, in which they may be effective in the stabilization of the structure. The binding profile of the complex with CT DNA was carried out by absorption spectra and fluorescence measurements. The experimental results were revealed that binding of the complex with CT-DNA via intercalation. The concentration and time dependent DNA cleavage studies including cleavage mechanism of the complex was performed by employing gel electrophoresis assay, where the complex has been found to cleave supercoiled DNA with high efficiency. Topoisomerase I and II alpha inhibition assays with Cu(II) complex were performed. Complex showed strong inhibition against both enzymes at 5 mu M. The cytotoxic activity of the complex was performed on human cell lines, breast cancer MDA-MB-231, lung carcinoma A549, colorectal adenocarcinoma HT29, neuroblastoma SH-SY5Y and normal cell line HEK-293 by MTT assay. The complex was exhibited remarkably good cytotoxic potential on cancer cell lines HT29 and SH-SY5Y.(c) 2022 Elsevier B.V. All rights reserved.