Seven metal-based bi-dentate NO azocoumarine complexes: Synthesis, physicochemical properties, DFT calculations, drug-likeness, in vitro antimicrobial screening and molecular docking analysis

Abstract

Herein, new Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes based on azocoumarin ligand, 2-[(E)-(2-oxo-2H-chromen-6-yl)diazenyl]-1-phenylbutane-1,3-dione (L), were synthesized and characterized via elemental analyses, IR, mass, UV–Vis spectra, magnetic susceptibility, conductivity measurements, and thermogravimetric analysis (TG). From IR spectra, it was elucidated that the azocoumarin ligand behaves as a neutral bi-dentate ligand and coordinates to the metal ions through the azo Nitrogen and carbonyl Oxygen. Number and position of the water molecules were investigated through thermal analysis. The molecular structures of the ligand (L) and its metal complexes were optimized theoretically using density functional theory (DFT) for various possible orientations of the H2O and Cl moieties around the metal-center, to find out the most reliable coordination modes. Moreover, the quantum chemical parameters were evaluated.The bioactivity of the ligand and its complexes were screened for their in vitro anti-bacterial and anti-fungal activity against series of pathogenic bacterial and fungal strains. The metal complexes possess high biological activity with low minimum inhibition concentration (MIC) against different organisms. In order to ascertain the bio-effect of the present compounds, their MIC was compared with previously reported MIC showing lower MIC values. Molecular docking was used to predict the binding efficiency between the prepared compounds and the receptor of E. coli(1HNJ), the target enzyme for the antimicrobial reagents. The protein-substrate interactions were investigated and the binding energies were calculated. The drug-likeness and ADMET prediction showed compliance with the Lipinski rule, and the compounds were found to have good absorption, distribution, metabolism, and excretion generally. The results were very encouraging, so we can say that these products are biologically active and can be used later in other applications towards drug development.