Synthesis of novel Schiff base metal complexes and their spectroscopic characterization, biological activity and molecular docking investigation

Abstract

In this study, Schiff base ligand namely N'-(3,4,5-trimethoxybenzylidene) benzohydrazide (I) and its metal complexes such as Cu(II) and La(III) (II and III) have been prepared. An elemental analysis, powder X-ray diffraction, FTIR, 1H NMR spectra, and thermal studies were used to characterize the Schiff base ligand and its metal complexes. According to infrared and 1H NMR analysis the ligand behaves as isobidentate. The electronic spectra reveals that charge transfer transitions are most centered on the ligand. An interesting fragmentation patterns was reported from thermal, biological activity and docking studies. Anti-bacterial studies were performed at least three times under identical conditions, these was estimated by measuring the zone of inhibition (mm) of the ligand and metal complexes against Escherichia coli, Bacillus subtilis, and Enterococcus faecalis strains of gram +ve and gram -ve bacteria. Molecular docking analysis was identified the molecular distance, energy account, and position of links contribution to the interaction between these complexes. These interactions demonstrate a strong interaction between the protein receptor molecule and the produced ligand and its La(III) complex, which were favorably affects the free binding energy. According to the values of interaction energies, the Cu(II) complex exhibited a significantly more stable interaction and a lower binding energy.