1. A new method has been developed for measuring the total antioxidant capacity of body fluids and drug solutions, based on the absorbance of the ABTS.+ radical cation. 2. An automated method for use on a centrifugal analyser, as well as a manual method, is described. 3. The procedure has been applied to physiological antioxidant compounds and radical-scavenging drugs, and an antioxidant rankin...

Comparison of the effectiveness of antioxidant activity of three thiol compounds, D-penicillamine, reduced L-glutathione, and 1,4-dithioerythritol, expressed as a radical-scavenging capacity based on the two independent methods, namely a decolorization 2,2'-azinobis[3-ethylbenzothiazoline-6-sulfonic acid] assay and a rotational viscometry, is reported. Particular concern was focused on the test...

Development of flow injection analysis (FIA) is reported for determination of total antioxidant capacity of alcoholic beverages (wines and spirits) by bienzymatically produced ABTS + and electrochemical detector using interdigitated gold electrode (IDE). The method is based on biamperometric measurements using ABTS jABTS redox couple. During the analysis, ABTS radical cation was bienzymatically...

A modified in vitro lipid peroxidation inhibition assay was used to guide the fractionation and the isolation of antioxidative principles of Fnnish pine bark extract. This approach yielded 3,4-dihydroxybenzoic acid (protocatechuic acid) and taxifolin-3-O-beta-glucopyranoside as major antioxidative compounds from the plant material. The structural elucidation of these compounds was undertaken wi...

A new computational approach for the determination of 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (DPPH-RSA) in food is reported, based on the concept of machine learning. Trolox standard was mix with DPPH at different concentrations to produce different colors from purple to yellow. Artificial neural network (ANN) was trained on a typical set of images of the DPPH radical re...

The total phenolic content and antioxidant capacity of three apple ciders produced in Poland were examined. The total phenolic content was determined by the Folin-Ciocalteau method and results were expressed in gallic acid equivalents with range from 0.21±0.003 to 0.30±0.004 mg/ml and Trolox equivalents ranging 0.88±0.012 to 1.24±0.015 mg/ml. The antioxidant activity was estimated by two method...

Total antioxidant capacity assays are recognized as instrumental to establish antioxidant status of biological samples, however the varying experimental conditions result in conclusions that may not be transposable to other settings. After selection of the complexing agent, reagent addition order, buffer type and concentration, copper reducing assays were adapted to a high-throughput scheme and...

Cyanine fluorophores exhibit greatly improved photostability when covalently linked to stabilizers, such as cyclooctatetraene (COT), nitrobenzyl alcohol (NBA) or Trolox. However, the mechanism by which photostabilization is mediated has yet to be determined. Here we present spectroscopic evidence that COT, when covalently linked to Cy5, substantially reduces the lifetime of the Cy5 triplet stat...

A new compound (C20H18O9) was isolated from bambara groundnut seeds (Vigna subterranea (L.) Verdc.) and identified as a luteolin glycoside based on 1H, 13C 2D nuclear magnetic resonance spectroscopy data previously reported data. This exhibited similar scavenging activity for DPPH radical to Trolox had higher inhibitory effect superoxide anion radicals than gallic acid Trolox. C20H18O9 an radic...