title: Quinone hemiacetal formation from protocatechuic acid during the DPPH radical scavenging reaction.
abstract: Protocatechuic acid was rapidly converted to protocatechuquinone 3-methyl hemiacetal and protocatechuquinone during the reaction with DPPH radical in methanol. The structure of the acetal was determined by comparing the NMR data with those of an authentic compound prepared by (diacetoxy)iodobenzene oxidation of protocatechuic acid.
authors.affiliation: Laboratory of Food Biochemistry, Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan.
authors.forename: Shizuka
authors.initials: S
authors.lastname: Saito
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Okamoto
authors.forename: Jun
authors.initials: J
authors.lastname: Kawabata
authors.forename: Takanori
authors.initials: T
authors.lastname: Kasai
mesh_terms: D001713:Biphenyl Compounds; D016166:Free Radical Scavengers / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry*; D062385:Hydroxybenzoates / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010851:Picrates / Q000737:chemistry*; D011809:Quinones / Q000138:chemical synthesis*
chemical_list: D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D005609:Free Radicals; D062385:Hydroxybenzoates; D010851:Picrates; D011809:Quinones; C009091:protocatechuic acid; C004931:1,1-diphenyl-2-picrylhydrazyl