title: Quantitative studies on structure-DPPH• scavenging activity relationships of food phenolic acids.
abstract: Phenolic acids are potent antioxidants, yet the quantitative structure-activity relationships of phenolic acids remain unclear. The purpose of this study was to establish 3D-QSAR models able to predict phenolic acids with high DPPH• scavenging activity and understand their structure-activity relationships. The model has been established by using a training set of compounds with cross-validated q2 = 0.638/0.855, non-cross-validated  r2 = 0.984/0.986, standard error of estimate = 0.236/0.216, and F = 139.126/208.320 for the best CoMFA/CoMSIA models. The predictive ability of the models was validated with the correlation coefficient r2(pred) = 0.971/0.996 (>0.6) for each model. Additionally, the contour map results suggested that structural characteristics of phenolics acids favorable for the high DPPH• scavenging activity might include: (1) bulky and/or electron-donating substituent groups on the phenol ring; (2) electron-donating groups at the meta-position and/or hydrophobic groups at the meta-/ortho-position; (3) hydrogen-bond donor/electron-donating groups at the ortho-position. The results have been confirmed based on structural analyses of phenolic acids and their DPPH• scavenging data from eight recent publications. The findings may provide deeper insight into the antioxidant mechanisms and provide useful information for selecting phenolic acids for free radical scavenging properties.
authors.affiliation: Research Center for Food Safety and Nutrition, Key Lab of Urban Agriculture (South), Bor S. Luh Food Safety Research Center, School of Agriculture & Biology, Shanghai Jiao Tong University, Shanghai, China. pjcolumbus@gmail.com
authors.forename: Pu
authors.initials: P
authors.lastname: Jing
authors.forename: Shu-Juan
authors.initials: SJ
authors.lastname: Zhao
authors.forename: Wen-Jie
authors.initials: WJ
authors.lastname: Jian
authors.forename: Bing-Jun
authors.initials: BJ
authors.lastname: Qian
authors.forename: Ying
authors.initials: Y
authors.lastname: Dong
authors.forename: Jie
authors.initials: J
authors.lastname: Pang
mesh_terms: D001713:Biphenyl Compounds / Q000737:chemistry*; D003198:Computer Simulation; D005504:Food Analysis; D016166:Free Radical Scavengers / Q000032:analysis / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry*; D006860:Hydrogen Bonding; D062385:Hydroxybenzoates / Q000032:analysis / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D010851:Picrates / Q000737:chemistry*; D021281:Quantitative Structure-Activity Relationship
chemical_list: D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D005609:Free Radicals; D062385:Hydroxybenzoates; D010851:Picrates; C004931:1,1-diphenyl-2-picrylhydrazyl