title: Oxidative dimer produced from a 2,3,4-trihydroxybenzoic ester.
abstract: The DPPH radical-scavenging abilities of the naturally occurring phenolic acid, 2,3,4-trihydroxybenzoic acid, and its methyl ester were evaluated. Both compounds in acetonitrile scavenged as many as four radicals compared to three or fewer radical consumption in acetone or ethanol. Only the ester showed relatively high ability in methanol. Oxidation with o-chloranil in acetonitrile resulted in methyl 2,3,4-trihydroxybenzoate giving a novel benzocoumarin-type dimer, its chemical structure being confirmed by spectroscopic evidence. The formation of this dimer might partly account for the higher radical-scavenging efficiency of the ester in acetonitrile or methanol.
authors.affiliation: Laboratory of Food Biochemistry, Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan.
authors.forename: Asuka
authors.initials: A
authors.lastname: Kodama
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Shibano
authors.forename: Jun
authors.initials: J
authors.lastname: Kawabata
mesh_terms: D001713:Biphenyl Compounds / Q000737:chemistry; D002703:Chloranil / Q000031:analogs & derivatives / Q000737:chemistry; D003374:Coumarins / Q000138:chemical synthesis*; D019281:Dimerization; D004952:Esters; D006834:Hydrazines / Q000737:chemistry; D062385:Hydroxybenzoates / Q000737:chemistry*; D010084:Oxidation-Reduction; D010851:Picrates
chemical_list: D001713:Biphenyl Compounds; D003374:Coumarins; D004952:Esters; D006834:Hydrazines; D062385:Hydroxybenzoates; D010851:Picrates; D002703:Chloranil; C004931:1,1-diphenyl-2-picrylhydrazyl; C017616:phenolic acid; C039499:2-chloranil