title: Electronic structure of some thymol derivatives correlated with the radical scavenging activity: theoretical study.
abstract: Molecules acting as antioxidants capable of scavenging reactive oxygen species (ROS) are of upmost importance in the living cell. Thymol derivatives exhibit various antioxidant activities and potential health benefits. Exploration of structure-radical scavenging activity (SAR) was approached with a wide range of thymol derivatives. To accomplish this task, the DPPH experimental assay along with quantum-chemical calculations were also employed for these compounds. By comparing the structural properties of the derivatives of interest, their antioxidant activity was explained by the formation of an intramolecular hydrogen bond and the presence of unsaturated double bond (-CHCH substituent) in their radical spices. Moreover, the delocalization of odd electrons in these radicals has been investigated by natural bond orbital analysis and interpretation of spin density maps. Reactivity order of the compound towards the ROS: HO, HOO, and O2(-) was found to be as HO>HOO >> O2(-).
authors.affiliation: Department of Food Hygiene, Faculty of Veterinary Medicine, Semnan University, Semnan, Iran. Electronic address: jebellija@profs.semnan.ac.ir.
authors.forename: Ashkan Jebelli
authors.initials: AJ
authors.lastname: Javan
authors.affiliation: Department of Chemistry, Sharif University of Technology, P.O. Box 11365-9516, Tehran, Iran.
authors.forename: Marjan Jebeli
authors.initials: MJ
authors.lastname: Javan
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry*; D008962:Models, Theoretical; D010084:Oxidation-Reduction; D017382:Reactive Oxygen Species / Q000737:chemistry*; D013943:Thymol / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D013943:Thymol
keywords: Bond dissociation energy; DFT study; DPPH assay; Ionization potential; Reactive oxygen species; Thymol radical scavenging activity