Investigation on biomolecular interactions of nickel(II) complexes with monoanionic bidentate ligands

August 13, 2018

Title

Investigation on biomolecular interactions of nickel(II) complexes with monoanionic bidentate ligands

Author

Arumugam Jayamani, Murugan Sethupathi, Stephen O. Ojwach, Nallathambi Sengottuvelan

Year

2018

Journal

Journal of Molecular Structure

Abstract

Reactions of monoanionic bidentate ligands 5-methylsalicylaldehyde (5-msal), 5-bromosalicylaldehyde (5-brsal), 5-nitrosalicylaldehyde (5-nsal) and 2-hydroxy-1-naphthaldehyde (2-hnap) with nickel perchlorate hexahydrate produced nickel(II) complexes 1–4, respectively. Single crystal X-ray analyses of complexes 1 and 2confirmed bidentate mode of the ligands with O˄O coordination to give square planar geometry around nickel atoms. Complexes 1–4 showed one quasi-reversible redox peak at cathodic region (−0.67 to −0.80 V) and one redox peak at anodic region (+1.08 to +1.44 V) assignable to the Ni(II)/Ni(I) and Ni(II)/Ni(III) redox couples, respectively. The complexes exhibited good bovine serum albumin (BSA) binding abilities with a maximum binding constant of 1.96 × 105 M−1. The binding of complexes with calf thymus DNA (ctDNA) showed that the binding affinity is consistent with an increase in steric bulk of the ligands. The nuclease activity of the complexes showed efficient oxidative cleavage in the presence of hydrogen peroxideas an oxidizing agent. The complexes showed higher zone of inhibition when screened for antimicrobial activity against bacteria and human pathogenic fungi.

Instrument

J-810

Keywords

Circular dichroism, DNA structure, Ligand binding, Inorganic chemistry, Biochemistry