Theoretical and experimental demonstration of mononuclear Ni(II) and dinuclear Ni(III) complexes concerning their catalytic activity, DNA/ protein binding efficacy

• Published in: Inorganica Chimica Acta 2024-10, Vol.571, p.122233, Article 122233
• Main Authors: Satapathi, Dibyendu, Das, Manik, Brandao, Paula, Kumar Das, Uttam, Laha, Soumik, Kundu, Pronab, Chandra Samanta, Bidhan, Maity, Tithi
• Format: Article
• Language: English
• Subjects: Catecholase; Deoxyribonucleic acid; Human Serum Albumin; Metal complex
• ISSN: 0020-1693
• DOI: 10.1016/j.ica.2024.122233

[Display omitted] •Developments of one mononuclear Ni(II) (1) and dinuclear Ni(III) (2) complexes from N, N, O and N, N, O, O donor Schiff base ligand respectively.•Complex 2 shows comparatively better catecholase-like activity than Complex 1.•complex 2 exhibits better DNA and protein binding potentiality, confirmed by implementing several biophysical studies.•Molecular docking results validate the experimental findings. The successful use of metal complexes in enzyme catalysis and biomedical applications boosts researchers to develop more and more metal-based compounds to inspect their said applications. In the present work one novel mononuclear Ni(II) [Ni(L1)2] (1) and one di nuclear Ni(III) complexes [Ni(L2)2(N3)2] (2) have been developed by utilizing N2O donor Schiff base ligand HL1 and N2O2 donor Schiff base ligand H2L2 respectively. The single crystal data analysis reveals that in complex 1 two deprotonated ligands coordinate to the Ni(II) forming a distorted octahedral geometry. The asymmetric unit of complex 2 comprises one deprotonated ligand (both the protons of phenolic –OH group were deprotonated), one azide anion, and one Ni(III). Two Ni(III) centers are connected via phenoxide bridging. Followed by the structural analysis the UV spectroscopic study is performed to understand the catecholase-like activity of the developed complexes by using 3,5-di-tertbutyl catechol (3,5-DTBC). The calculated turnover numbers (Kcat) for both complexes disclose the fact that complex2 is more susceptible to this catalytic process than 1. During the catalysis process, the production of Ni(II) in the case of complex2is favorable and this is the main factor to show its higher susceptibilitytowards the catalytic process. The biomedical applicability in terms of anticancer and antibacterial of complexes 1 and 2 is assessed by evaluating their interaction ability with DNA and HSA with the help of several spectroscopic approaches. The remarkably high complex-macromolecules binding constant values, obtained from electronic titration approve the binding efficacy of the target complexes (order ∼ 105). But if a tiny comparison is done then it is seen that complex 2 shows better DNA and HSA binding efficacy. The theoretical approach using molecular docking study fully validates the experimental findings.