title: Evaluation of the antioxidant capacity of natural polyphenolic compounds using a macrocyclic Ni-(II) complex-catalysed Briggs-Rauscher reaction.
abstract: This paper reports a method for evaluating antioxidant capacity based on the inhibitory effects of a macrocyclic Ni(II) complex-catalysed Briggs-Rauscher reaction. The macrocyclic Ni(II) complex NiL(ClO4)2, in which L is 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene, is a porphyrin-like compound, the structure of which can be found in certain enzymes. The experiments indicated that three natural compounds could temporarily quench the oscillations for a period of time prior to regeneration of oscillations. The inhibition time was related to the compound type and concentration; thus, procedures for evaluating the antioxidant activities of polyphenolic compounds were successfully established. Three polyphenolic compounds were tested to evaluate their antioxidant activities: protocatechuic acid, rutin hydrate and procyanidin. Of these three naturally occurring compounds, procyanidin was found to be the most efficient antioxidant. We have also discussed the reaction of the antioxidant with the hydroperoxyl radical (HOO) present in the oscillating system.
authors.affiliation: Department of Chemistry, Anhui University, Hefei 230601, PR China.
authors.forename: Mengshuo
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Chemistry, Anhui University, Hefei 230601, PR China. Electronic address: hugang@ustc.edu.
authors.forename: Gang
authors.initials: G
authors.lastname: Hu
authors.affiliation: Department of Chemistry, Anhui University, Hefei 230601, PR China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D044946:Biflavonoids; D002384:Catalysis; D002392:Catechin; D062385:Hydroxybenzoates; D017665:Hydroxyl Radical / Q000737:chemistry; D047028:Macrocyclic Compounds / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry; D059808:Polyphenols / Q000494:pharmacology*; D044945:Proanthocyanidins; D012431:Rutin
chemical_list: D000975:Antioxidants; D044946:Biflavonoids; D062385:Hydroxybenzoates; D047028:Macrocyclic Compounds; D010936:Plant Extracts; D059808:Polyphenols; D044945:Proanthocyanidins; D017665:Hydroxyl Radical; C009091:protocatechuic acid; C017674:procyanidin; D012431:Rutin; D009532:Nickel; D002392:Catechin
keywords: Antioxidant; Briggs–Rauscher reaction; Ethanol (PubChem CID: 702); Evaluation; Hydrogen peroxide (PubChem CID: 784); Macrocyclic Ni(II) complex; Malonic acid (PubChem CID: 867); Naturally occurring compounds; Potassium iodate (PubChem CID: 23665710); Procyanidin (PubChem CID: 107876); Protocatechuic acid (PubChem CID: 72); Rutin hydrate (PubChem CID: 16218542); Sulphuric acid (PubChem CID: 1118)