Georgieva, MiglenaArgirova, MariaYancheva, Denitsa2025-10-212025-10-212025-122210-271XPURE: 132672472PURE UUID: f79aa973-6eb8-4899-ba20-ba23027408c9Scopus: 105015863801WOS: 001575056000001ORCID: /0000-0003-0839-4123/work/194834778http://hdl.handle.net/10362/189596Funding Information: This research was funded by the National Science Fund of Bulgaria, Contract number KП-06-H73/3. D.Y. is grateful for the financial support of the European Union-NextGenerationEU, through the National Recovery and Resilience Plan of the Republic of Bulgaria, Project No. BG-RRP-2.004-0002, “BiOrgaMCT”. Publisher Copyright: © 2025 The Author(s)A detailed computational study was performed to explain the relationship between the experimentally established radical scavenging ability of 1H-benzimidazol-2-yl hydrazones and their structural properties. Two dihydroxypheyl substituted compounds with high antioxidant activity and one substantially less active dimethoxyphenyl derivative were studied in benzene and water, mimicking the nonpolar and polar biological medium. The possibility for different reaction pathways was evaluated by Gibbs free energies of possible reactions, respective transition states and rate constants with •ОСН3, •OOH and •ОOСН3. It was found that in nonpolar medium, deactivation of free radicals would occur only by HAT mechanism. In water, deactivation of free radicals would proceed mainly by SET after deprotonation. In both solvents, the three compounds are able to deactivate •OOCH3 and stop the propagation of the lipid peroxidation reaction. The calculated overall rate coefficients showed that the 3,4-dihydroxy derivative is the most reactive one against all studied free radicals.113440955engAntioxidant mechanismDFT studyHydroxy- or methoxy-substituted 1H-benzimidazole-2-yl hydrazonesRate constantsTautomeric formsBiochemistryCondensed Matter PhysicsPhysical and Theoretical Chemistryjournal article10.1016/j.comptc.2025.115491https://www.scopus.com/pages/publications/105015863801https://www.webofscience.com/wos/woscc/full-record/WOS:001575056000001