Synthesis, characterizations, crystal structures, BSA-binding, molecular docking, and cytotoxic activities of nickel(II) and copper(II) coordination complexes with bidentate N,S-chelating ligand

Abstract

In the present investigation, we report the synthesis and characterization of three novel nickel(II) [Ni(L)₂] (1) and copper(II) [Cu(L)₂] (2a) and [Cu(L)₂] (2b) complexes, which are made through the coordination of (E)-1-(2-methoxybenzylidine)-4-phenylethiosemicarbazone (HL) as bidentate N,S-ligand. Several modern techniques including experimental electronic and fluorescence spectroscopy, single-crystal X-ray crystallography, molecular docking and BSA-binding are used to characterize the isolated coordination compounds. X-ray crystallography, FT-IR and UV–visible spectra agree with the observed crystal structures. The crystallographic and spectroscopic studies confirmed that these complexes display four-coordinate square-planar trans-[MN₂S₂] coordination geometry, whose central metal(II) atom lies on the center of symmetry. Complexes 1 and 2a crystallized in the orthorhombic system of the space group Pbca whereas 2b crystallized in the monoclinic system of P2₁/c. The binding affinity of complexes towards bovine serum albumin (BSA) was determined by UV–visible and fluorescence spectrophotometric methods. The cytotoxic/antiproliferative potential of the synthesized compounds on human cell lines was also investigated by MTT assay.

Keywords:

• Coordination complexes
• BSA binding studies
• molecular docking
• protein interaction
• cytotoxic studies

Acknowledgments

The authors thank the Sophisticated Analytical Instrument Facility (SAIF), STIC Cochin for single-crystal data collection of [Ni(L)₂] (1), and SAIF IIT Patna for [Cu(L)₂] (2a) and [Cu(L)₂] (2b). B. Mohan and Noorussabah acknowledge CSIR and TEQIP-II, NIT Patna, respectively, for their fellowships.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Council of Scientific and Industrial Research (CSIR), New Delhi, India [grant number 01(2856)/16/EMR-II].