title: A theoretical investigation on DPPH radical-scavenging mechanism of edaravone.
abstract: The mechanism of edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) to scavenge DPPH radical is clarified by density functional theory (DFT) calculations. It is revealed that H-atom-abstraction rather than electron-transfer reaction is involved in the radical-scavenging process of edaravone, and H-atom at position 4 is readily to be abstracted. The C-H bond dissociation enthalpy (BDE) of edaravone is higher than the O-H BDE of alpha-tocopherol, accounting for the activity difference between the two antioxidants. As substituents have little influence on the C-H BDE, 2-pyrazolin-5-one is recognized as the active center for edaravone.
authors.affiliation: Laboratory for Computational Biology, Shandong Provincial Research Center for Bioinformatic Engineering and Technique, Shandong University of Technology, Zibo 255049, P.R. China.
authors.forename: Lan-Fen
authors.initials: LF
authors.lastname: Wang
authors.forename: Hong-Yu
authors.initials: HY
authors.lastname: Zhang
mesh_terms: D000983:Antipyrine / Q000031:analogs & derivatives* / Q000737:chemistry*; D001713:Biphenyl Compounds; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D000077553:Edaravone; D004579:Electron Transport; D016166:Free Radical Scavengers / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry; D008958:Models, Molecular; D010851:Picrates / Q000737:chemistry*; D013329:Structure-Activity Relationship; D013816:Thermodynamics; D014810:Vitamin E / Q000737:chemistry
chemical_list: D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D005609:Free Radicals; D010851:Picrates; D014810:Vitamin E; D006859:Hydrogen; C004931:1,1-diphenyl-2-picrylhydrazyl; D000077553:Edaravone; D000983:Antipyrine