One-electron transfer equilibria between seven phenothiazines were characterized by pulse radiolysis, producing radical-cations via oxidation by Br2�? or (SCN)2�? radicals. The reduction potentials of the phenothiazine radicals were determined by cyclic voltammetry. As an independent check, the redox equilibrium between one ...

Sulfhydryl organic compounds described as laccase inhibitors: dithiothreitol, thioglycolic acid, cysteine, diethyldithiocarbamic acid, and sodium azide were tested for their activity toward laccase of Trametes versicolor in different test systems utilising 2, 2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 2, 6-dimethoxyphenol as enzyme substrates. Only ...

Application of interdigitated array microelectrodes as electrochemical sensors for determination of antioxidant capacity is reported. Electrochemical measurements with interdigitated electrodes (IDE) were studied in both stationary solutions and the flow system. The method is based on biamperometric measurements using ABTS(*+)|ABTS redox couple in phosphate buffer solution, pH ...

Total reactive antioxidant potential (TRAP) of resinous exudates from Heliotropium species was evaluated by measuring the bleaching of stable free radicals. The antioxidant capacity of the resinous exudates in Trolox equivalents, evaluated from the bleaching of ABTS derived radical cations, ranged from 2.0 M (H. ...

Cerium (Ce) is a rare earth metal that is not known to have any biological role. Cerium oxide materials of several sizes and shapes have been developed in recent years as a scaffold for catalysts. Indeed even cerium oxide nanoparticles themselves have displayed catalytic activities and antioxidant properties in tissue culture and animal models. Because of ceria's ability to cycle between the +3 ...

On-line method, which combines HPLC distribution and post-column reaction, was designed for the search of individual antioxidants. Optimization of the assay was performed evaluating optimal ABTS(+) radical cation concentration in the reactor, reaction time, impact of flow rate, reaction coil length. HPLC-ABTS assay ...

The antioxidant properties of magnolol and honokiol were evaluated in the experimental systems of reducing ONOO(-) and (1)O(2), bleaching ?-carotene in linoleic acid (LH) emulsion, and trapping 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS(+)) and 2,2'-diphenyl-1-picrylhydrazyl radical ...

The aim of this study was to investigate antioxidant capacity of nine Fabaceae species collected on the mountains of Serbia and Montenegro. Antioxidant assays with various reaction mechanisms were used, including total phenolic content by Folin-Ciocalteu, DPPH radical scavenging capacity, Trolox equivalent antioxidant capacity (TEAC) values by ABTS ...

The antioxidant potency of Acacia salicina extracts was investigated. Total antioxidant capacity was determined using an ABTS(+) assay. Superoxide radical scavenging was measured using riboflavin-light-nitro blue tetrazolium (NBT) assay. In addition, the content of phenols, total flavonoids and sterols were measured in the tested extracts. The petroleum ...

The study presents the general method of standardization of estimations of total antioxidant activity (TAA) by extrapolating parameters to zero sample concentration based on a pseudo-first-order kinetics model. To test its suitability, the method was applied to the ABTS cation radical scavenging assay, as the first choice. Two ...

The synthesis of three types of pulvinic acid analogues, using a diversity-oriented strategy starting from a single compound, dimethyl l-tartrate, is described. Lacey-Dieckmann condensation, alcohol dehydration and Suzuki-Miyaura cross-couplings were employed in the course of the analogues syntheses. The evaluation of the antioxidant properties of the 28 synthesized analogues was carried out using ...

The antioxidant capacities of ferrocenyl Schiff bases including o-(1-ferrocenylethylideneamino)phenol (OFP), m-(1-ferrocenylethylideneamino)phenol (MFP), and p-(1-ferrocenylethylideneamino)phenol (PFP) were evaluated in 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH), Cu(2+)/glutathione (GSH), and hydroxyl radical (()OH)-induced oxidation of DNA, and in trapping ...

Pagodane radical cation and its transformation into pagodiene radical cation was observed by time-resolved FDMR (fluorescence detected magnetic resonance). Other highly unstable radical cations are discussed as well.

Pagodane radical cation and its transformation into pagodiene radical cation was observed by time-resolved FDMR (fluorescence detected magnetic resonance). Other highly unstable radical cations are discussed as well.

Pulse radiolysis studies on hydroxyl (*OH) radical reactions of selenomethionine (SeM), a selenium analogue of methionine, were carried out, and the resultant transient radical cations and their subsequent reactions have been reported. At pH<3, the >Se*-OH radical adducts produced on reaction of SeM with *OH ...

Dichlorocarbene radical cation reacts with benzaldehyde in the gas phase by oxygen radical anion abstraction, generating a new carbene radical cation population. The ion population consists of two isomeric carbene radical cations. Molecular orbital ...

Cinnamoylphenethylamine (CNPA) derivatives including feruloylphenethylamine (FRPA), caffeoylphenethylamine (CFPA), cinnamoyltyramine (CNTA), feruloyltyramine (FRTA) and caffeoyltyramine (CFTA) were synthesized in order to investigate the influence of the number and position of hydroxyl group on Cu(2+)/glutathione (GSH) and 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH)-induced oxidation of ...

Cyclooxygenase enzymes house spatially distinct cyclooxygenase- and peroxidase-active sites. The two-electron reduction of peroxides to their corresponding alcohols by the heme bound in the peroxidase-active site converts the heme to a ferryloxoprotoporyphrin cation radical, with a reductant providing the two electrons necessary to bring the heme back to ...

We developed a new method for the analysis of active antioxidants that is based on their reactions with the ABTS+. cation radical obtained by oxidation of ABTS, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt. The feasibility of this method was confirmed by electrochemical and kinetic studies ...

The kinetics and mechanisms of the reactions of organic cations of different types with neutral radicals, radical-anions, and radical-cations are considered and the dependences of the rates of these reactions on the nature of the substituents in the reactants, the charges on the radicals, the ...

The spectrophotometric method of antioxidants determination using recombinant laccase Polyporus pinsitus (rPpL) and Myceliophthora thermophila (rMtL) was developed. The method includes simultaneous oxidation of the antioxidant and high reactive laccase substrate producing chromophoric radical cation. As laccase substrates ABTS and ...