title: A Kinetic Approach in the Evaluation of Radical-Scavenging Efficiency of Sinapic Acid and Its Derivatives.
abstract: A kinetic approach was used to determine the radical scavenging activities of sinapic acid and its derivatives: sinapine, 4-vinylsyringol, syringic acid, syringaldehyde, and ethyl, propyl and butyl sinapate. The responses were expressed as rates of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH˙) scavenging (RS), superoxide radical (O₂˙-) scavenging (RFF), and β-carotene bleaching in the emulsion system (RB). ForRSandRB, the esters of sinapic acid showed the highest responses while, forRFF, this was seen for syringic acid. The effectiveness of the selected compounds for scavenging these free radicals was also determined at a fixed endpoint. The early response parameters were demonstrated to be good discriminators in assessing differences for antioxidants with comparable fixed endpoint activity. The primary feature that ranks the kinetic data and the endpoint determinations is interpreted in terms of the mechanisms of the reactions involved in each of the assays conducted.
authors.affiliation: Biotechnical Faculty, University of Ljubljana, SI-1111 Ljubljana, Slovenia. neda.neca@hotmail.com.
authors.forename: Neda
authors.initials: N
authors.lastname: Nićiforović
authors.affiliation: Biotechnical Faculty, University of Ljubljana, SI-1111 Ljubljana, Slovenia. tomaz.polak@bf.uni-lj.si.
authors.forename: Tomaž
authors.initials: T
authors.lastname: Polak
authors.affiliation: Slovenian NMR Centre, National Institute of Chemistry, SI-1001 Ljubljana, Slovenia. damjan.makuc@ki.si.
authors.forename: Damjan
authors.initials: D
authors.lastname: Makuc
authors.affiliation: Biotechnical Faculty, University of Ljubljana, SI-1111 Ljubljana, Slovenia. natasa.poklar@bf.uni-lj.si.
authors.forename: Nataša
authors.initials: N
authors.lastname: Poklar Ulrih
authors.affiliation: Biotechnical Faculty, University of Ljubljana, SI-1111 Ljubljana, Slovenia. helena.abramovic@bf.uni-lj.si.
authors.forename: Helena
authors.initials: H
authors.lastname: Abramovič
mesh_terms: D003373:Coumaric Acids / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology*; D007700:Kinetics
chemical_list: D003373:Coumaric Acids; D016166:Free Radical Scavengers; C073734:sinapinic acid
keywords: antioxidant activity; radical scavenging kinetics; radical scavenging mechanisms; sinapic acid