Isolation, vibrational analysis, quantum chemical studies, nature of bonding, and molecular docking studies of triterpenoid isolates from Ganoderma lucidum as potent typhoid fever agent

Abstract

The bacteria Salmonella Typhi is the source of the dangerous and perhaps fatal disease known as typhoid fever. Typhoid fever treatment is difficult despite the availability of potent medications due to the rise of multi-drug resistance strains. Herein, the extraction, LC-MS and FT-IR spectral characterization, density functional theory (DFT) and molecular docking investigation of 3,15-dihydroxy-11-toxolanost-8,24-dien-26-oic acid (C30H45O5) [MDC_1], Ganoderic acid F (C32H41O9) [MDC_2], and Ganolucidic acid E (C30H43O5) [MDC_3] isolated compounds from G. lucium against Salmonella Typhi enzyme, DNA gyrase B is presented along with the influence of solvation in polar and non-polar solvents. The FT-IR spectral results show that the triterpenoid extract of G. lucidum contains oxygen atoms, which mainly exist in functional groups (such as CO, O–H, C–O) and are consistent with the general molecular structures of triterpenoids. The reactivity parameters in the gas phase show that MDC_1 and MDC_3 have higher energy gaps whereas MD_2 has the lowest energy gap, indicating that it is more reactive than the other complexes. The energy gap of the compounds in solvent also shows a little shift, compared to the energy gap in Ethanol and Heptane, respectively. The results of the molecular docking study revealed several small molecules with strong binding affinities for the protein targets, suggesting that they could be used as potential therapeutics for typhoid fever. Therefore, this study suggests that molecular docking is a powerful tool for identifying novel therapeutics against tropical diseases such as typhoid fever.