Density functional theory molecular modelling, DNA interactions, antioxidant, antimicrobial, anticancer and biothermodynamic studies of bioactive water soluble mixed ligand complexes

Abstract

A novel series of bioactive water soluble mixed ligand complexes (1–5) [M^II(L)(phen)AcO]. nH₂O {where M = Cu (1) n = 2; Co (2), Mn (3), Ni (4), n = 4 and Zn (5) n = 2} were synthesized from 2-(2-Morpholinoethylimino) methyl)phenol Schiff base ligand (LH), 1, 10-phenanthroline and metal(II) acetate salt in a 1:1:1 stoichiometric ratio and characterized by several spectral techniques. The obtained analytical and spectral data suggest the octahedral geometry around the central metal ion. Density functional theory calculations have been further supportive to explore the optimized structure and chemical reactivity of these complexes from their frontier molecular orbitals. Gel electrophoresis result indicates that complex (1) manifested an excellent DNA cleavage property than others. The observed binding constants with free energy changes by electronic absorption technique and DNA binding affinity values by viscosity measurements for all compounds were found in the following order (1) > (2) > (4) > (5) > (3) > (LH). The binding results and thermodynamic parameters are described the intercalation mode. In vitro antioxidant properties disclose that complex (1) divulges high scavenging activity against DPPH^•, ^•OH, O₂^−• NO^•, and Fe³⁺. The antimicrobial reports illustrate that the complexes (1–5) were exhibited well defined inhibitory effect than ligand (LH) against the selected different pathogenic species. The observed percentage growth inhibition against A549, HepG2, MCF-7, and NHDF cell lines suggest that complex (1) has exhibited superior anticancer potency than others. Thus, the complex (1) may contribute as potential anticancer agent due to its unique interaction mode with DNA.GRAPHICAL ABSTRACT

Communicated by Ramaswamy H. Sarma

Keywords:

• Density functional theory
• antioxidant
• antimicrobial
• anticancer
• DNA interactions

Acknowledgments

Great acknowledgement is delivered to Department of Science and Technology (DST) – Science and Engineering Research Board (SERB), Government of India, New Delhi for the financial support granted with the Project Ref.No.SR/FT/CS – 117/2011 dated 29.06.2012 and we express deepest gratitude to the Managing Board, Dean, Principal and Chemistry Research Centre MSEC, Kilakarai for providing research facilities. RVS thanks the department of chemistry and the management of Madras Christian College for the support and encouragement.

Disclosure Statement

No potential conflict of interest was reported by the author(s).