Synthesis, characterization of Schiff base metal complexes with 1, 3 propanediamine as secondary chelates and their DNA binding, DNA cleavage, cytotoxicity, antioxidant and activities

Abstract

A series of Cu(II), Co(II), Ni(II), and Zn(II) complexes were synthesised from ternary Schiff base ligand (ts) and 1,3-propanediamine (pda). These complexes were characterised using analytical and spectroscopic techniques. All these metal complexes have an octahedral geometry, which is supported by spectro-analytical experimental data. The fabricated Schiff base coordinates with the metal via imine nitrogen, a phenolic oxygen atom, and carboxylate anion as a monobasic tridentate. Thermal properties were also investigated. Antimicrobial studies were carried out against fungi and pathogenic (bacterial) organisms and a good zone of inhibition was observed irrespective of complexes. Free radical scavenging assays were performed by DPPH and H2O2 methods. The results of these two studies revealed that the Cu(II) and Zn(II) complexes were more active. The binding mode of calf thymus (Ct-DNA) to the metal complexes was analysed by the electronic absorption spectroscopy and viscosity measurement study. The findings revealed that the complex bound with DNA via a groove with electrostatic interactionand the copper complex showed a higher binding constant value. Cytotoxicity of the Schiff base and its complexes were evaluated with the breast cancer (MCF-7) cell line and all complexes exhibited moderate toxicity.