Punica granatum pericarp extract catalyzed green chemistry approach for synthesizing novel ligand and its metal(II) complexes: Molecular docking/DNA interactions

Abstract

The gallic acid (GA) obtained from the ethanolic extract of Pomegranate(Punica granatum) pericarp, was successfully applied as a green and effective natural catalyst for the synthesis of novel quinoline based amino acid Schiff base ligand, L (C16H14N4O3) and its divalent metal complexes (where M = Fe(II), Co(II), Ni(II), Cu(II); L=(E)-2-(((2-hydroxyquinolin-3-yl)methylene)amino)-3-(1H-imidazol-5-yl)propanoic acid) through condensation of 2-hydroxyquinoline-3-carbaldehyde with L-histidine, employing a simple physical grinding technique. The ligand and the complexes denoted as [M(LH2)2] were characterized by advanced spectroscopic and analytical techniques. The configuration of the as synthesized complexes is deduced to be octahedral. The molecular docking experiments were performed by using an Autodock-4 tool to find the binding mode of the metal(II) complexes to B-DNA dodecamer. The metal complex interactions with CT-DNA were studied using spectroscopic techniques, viscosity analysis and thermal denaturation method. In UV-visible irradiation with pUC19 DNA the photo-induced cleavage studies interpreted the photonuclease characteristics of the metal(II) complexes.