Theoretical Investigation of Natural Flavonoids as Dual-Action Inhibitors of Microbiologically Influenced Corrosion...

Sulfate-reducing bacteria are among the main contributors to microbiologically influenced corrosion (MIC) through the production of corrosive sulfide species. In this work, Novobiocin, Jaceosidin, and Hispidulin were examined as potential inhibitors for suppressing MIC through surface adsorption and disruption of bacterial electron-transfer processes. Electronic structure analysis revealed that Novobiocin exhibits the smallest HOMO-LUMO energy gap (3.62 eV) compared with Jaceosidin (4.15 eV) and Hispidulin (4.17 eV), this behavior improved charge-transfer ability and stronger interaction potential with both the Fe surface and the biological target. Molecular docking results showed stronger binding affinities for Hispidulin (-4.66 kcal/mol) and Jaceosidin (-4.50 kcal/mol) toward Cytochrome c₃ compared to Novobiocin (-2.25 kcal/mol), this may contribute to interference with bacterial electron-transfer activity. Monte Carlo simulations also predicted strong adsorption on the Fe surface in the following order with the Fe surface, following the order: Novobiocin (232.23 kcal/mol) > Jaceosidin (171.84 kcal/mol) > Hispidulin (162.75 kcal/mol).

DFT calculations were performed to investigate the electronic properties of the studied compounds. Docking calculations were conducted against Cytochrome c₃ (PDB ID: 1J0P) to evaluate ligand-protein interactions. Adsorption behavior on the Fe(110) surface was studied using Monte Carlo simulations and MD simulations under NVE conditions were used to examine the thermal stability of the inhibitor-surface systems using the COMPASSIII force field to evaluate the thermal stability and interaction dynamics of the inhibitor-surface systems.