Results in Chemistry (Dec 2023)
Quantum chemical studies, spectroscopic NMR and FT-IR analysis, and molecular docking investigation of 3,3′-di-O-methyl ellagic acid (DMA) as a potent Mycobacterium tuberculosis agent
Abstract
Tuberculosis which is mainly caused by Mycobacterium tuberculosis remains of public health importance due to the resistance of the causative pathogen to the present antibiotics used as treatment options. This resistance has led to the need for the discovery of new treatment options. Herein, the isolation, geometrical optimization, spectroscopic NMR and FT-IR analysis, a study of weak interactions, electronic properties, and the in-silico biological activity of 3,3′-di-O-methyl ellagic acid (DMA) were determined. In addition, the effect of solvent on the kinetic stability, reactivity, and other electronic properties of DMA was determined in three solvents; DMSO, methanol, and water. Also, the biological activity potential and the drug-likeness of DMA were determined using molecular docking protocol and ADMET studies. The studied compound was isolated using column and thin-layer chromatography techniques while characterization was done using spectroscopic techniques. Key vibrations in the compound are C = O vibrations, C = C vibrations, C-H vibrations, –CH3 vibrations, and O-H vibrations. A study of quantum descriptors revealed that DMA is more reactive in water with an energy gap of −3.162 eV and those in three solvents are −3.163, −3.944, and −4.3022 eV in methane, gas, and water respectively. The compound shows great optical potentials with dipole moments of 3.2415D, 5.221D, 5.2015D, and 4.469D in water, DMSO, methanol, and Gas-phase respectively which are greater than that of urea used in the comparison. The QTAIM analysis based on the bond ellipticity < 0.5 suggests the presence of covalent bonds within the atoms of the studied compound. The MESP result shows the presence of π- H bond interaction within the OCH3 and oxygen atom. Molecular docking studies of the studied compound were carried out employing proteins 1W2G, 1YWF, and 1F0N proteins for mycobacterial tuberculosis and the standard drug isoniazid. The result was compared with that of a standard drug. The binding affinities of −7.1, −6.9, and −7.1 kcal/mol for 1W2G, 1YWF, and 1F0N were obtained, and −5.9, −5.9 and −6.0 kcal/mol for the standard drug with 1W2G, 1YWF and 1F0N. These results show that the studied compound has greater biological activity against these proteins as compared to the standard drug. ADMET studies show that the studied compound has great drug-likeness and bioavailability since it did not violate any of Lipinski’s rule of five.
