Prevention of a systematic underestimation of antioxidant activity in competition assays. The impact of unspecific reactions of the reactive species.

C.P. Beljaars, J.M. Balk, A. Bast, G.R. Haenen

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

In antioxidant competition assays, an antioxidant (A) and a detector compound (D) compete for a reactive species (R). In the evaluation of these assays, it is tacitly assumed that all of R is captured by either D or A. Due to the - by definition - high reactivity of R, unspecific reactions of R are likely to occur and neglecting these reactions will result in a systematic underestimation of antioxidant activity. It was shown that in the standard hydroxyl radical scavenging assay this was indeed the case; the inaccurate mathematical evaluation resulted in an underestimation of antioxidant activity of 25% in this competition assay. The systematic underestimation of antioxidant activity can be prevented by using an adjusted Stern-Volmer equation that takes into account that only part of R is captured by D or A.
Original languageEnglish
Pages (from-to)346-350
Number of pages5
JournalBiochemical and Biophysical Research Communications
Volume392
Issue number3
DOIs
Publication statusPublished - 12 Feb 2010

Keywords

  • Antioxidant
  • Competition assay
  • Reaction rate
  • Stern-Volmer
  • Hydroxyl radical
  • RADICAL-SCAVENGING ABILITY
  • HYDROXYL RADICALS
  • HYDROGEN-PEROXIDE
  • PULSE RADIOLYSIS
  • AQUEOUS-SOLUTION
  • RATE CONSTANTS
  • CHEMILUMINESCENCE
  • COUMARIN
  • METABOLITES
  • OXIDATION

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