Antimicrobial efficacy of phenanthrenequinone based Schiff base complexes incorporating methionine amino acid: Structural elucidation and in vitro bio assay

•Synthesis of good DNA metallointercalators.•Synthesis of better antimicrobial agents of metal complexes.•Designing and synthesis of N3O type square planar complexes.•Efficient amylase inhibition activity of the copper complex.•Synthesis of better DNA chemical nucleases.

This work focuses the synthesis and characterization of few novel mixed ligand Schiff base metal complexes and their biological activities. For deriving the structural aspects, spectral techniques such as FT-IR, UV–Vis., 1H NMR, Raman, EPR and the physicochemical characterizations including elemental analysis, molar conductance and magnetic susceptibility method have been involved. All the complexes adopt square planar geometry. DNA binding ability of these complexes has been explored using diverse techniques viz. UV–Vis. absorption, fluorescence spectroscopy, viscometry and cyclic voltammetry. These studies prove that CT-DNA binding of the complexes follows the intercalation mode. Comparative DNA oxidative cleavage ability of the complexes has been done under ultraviolet photo radiation on pUC19 DNA. In addition, the biocidal action of the complexes has been investigated against few pathogenic bacteria and fungi by disc diffusion method. Importantly, the amylase inhibition activity of Cu(II) complex has been explored. The amylase inhibition property has been found to be increased upon increasing the complex concentration.

Graphical abstractFew novel mixed ligand Schiff base metal complexes incorporating methionine amino acid act as efficient DNA binding and DNA cleaving agents. They are good antimicrobial reagents. Copper complex is found to be good amylase inhibitor.Figure optionsDownload full-size imageDownload as PowerPoint slide