title: DPPH-scavenging activities and structure-activity relationships of phenolic compounds.
abstract: Thirty-eight phenolic compounds (including 31 flavonoids) were examined for their DPPH radical-scavenging activities, and structure-activity relationships were evaluated. Specifically, the presence of an ortho-dihydroxyl structure in phenolics is largely responsible for their excellent anti-radical activity. 3-Hydroxyl was also essential to generate a high radical-scavenging activity. An increasing number of hydroxyls on flavones with a 3',4'-dihydroxyl basic structure, the presence of a third hydroxyl group at C-5', a phloroglucinol structure, glycosylation and methylation of the hydroxyls, and some other hydroxyls, for example 5-, and 7-hydroxyl in ring A, decreased the radical-scavenging activities of flavonoids and other phenolics.
authors.affiliation: College of Science, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Cheng-Dong
authors.initials: CD
authors.lastname: Zheng
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.forename: Hu-Qiang
authors.initials: HQ
authors.lastname: Li
authors.forename: Xiao-Jing
authors.initials: XJ
authors.lastname: Xu
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Gao
authors.forename: An-Ling
authors.initials: AL
authors.lastname: Zhang
mesh_terms: D001713:Biphenyl Compounds / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry*; D015394:Molecular Structure; D010636:Phenols / Q000737:chemistry*; D010851:Picrates / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010636:Phenols; D010851:Picrates; C004931:1,1-diphenyl-2-picrylhydrazyl