Novel Schiff Bases Ligands and Their Complexes: Thermal Analysis, Antibacterial Activity, and Molecular Docking

Kadhem, Basher J.; Alshawi, Jassim; Alsalim, Tahseen A.; Abdalla, Mohnad

doi:10.21608/ejchem.2021.95037.4571

Novel Schiff Bases Ligands and Their Complexes: Thermal Analysis, Antibacterial Activity, and Molecular Docking

Document Type : Original Article

Authors

¹ Department of Chemistry, Faculty of Education for Pure Sciences, University of Basrah, Basrah, 61001, Iraq.

² Department of Chemistry, Faculty of Education for Pure Sciences, University of Basrah, Basrah, 61001, Iraq

³ Key Laboratory of Chemical Biology (Ministry of Education), Department of Pharmaceutics, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, 44 Cultural West Road, Shandong Province 250012, PR China

10.21608/ejchem.2021.95037.4571

Abstract

Abstract
The transition metal complexes of novel tetradentate-ketoenamine ligands were synthesised by condensing β-diketone (acetylacetone, 3-chloro acetylacetone) with 4,4'-methylenedianiline. Fourier-transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (1H NMR) spectroscopy, carbon-13 NMR (13C NMR) spectroscopy, electron ionisation mass spectrometry (EIMS), elemental analysis, and UV-visible (UV-Vis) spectroscopy were used to describe the compounds while thermogravimetric (TG/DTG) analysis was used to investigate the thermal breakdown of the complexes. All of the complexes showed outstanding stability as well as different degrees of thermal decomposition. Antibacterial activity was tested using gram-positive (Bacillus subtilis, Staphylococcus aureus) and gram-negative (Bacillus subtilis, Staphylococcus aureus) bacteria (Escherichia coli, Salmonella typhi). Minimal inhibitory concentrations (MICs) of 0.5 to 2 mM/ml and minimum bacterial concentrations (MBCs) of 2 to 4 mM/ml were used in this study. A molecular docking study was also conducted to ensure that the compounds connected well to the active sites of the target enzymes; such as topoisomerase II DNA gyrase enzymes (2XCT) and methicillin-resistant Staphylococcus aureus (MRSA,2x3f.pdb).

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