In vitro antioxidant activity of coffee compounds and their metabolites

J Agric Food Chem. 2007 Aug 22;55(17):6962-9. doi: 10.1021/jf0710985. Epub 2007 Jul 27.


In this paper we report the antioxidant activity of different compounds which are present in coffee or are produced as a result of the metabolism of this beverage. In vitro methods such as the ABTS*+ [ABTS = 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] decolorization assay and the oxygen radical absorbance capacity assay (ORAC) were used to assess the capacity of coffee compounds to scavenge free radicals. The importance of caffeine metabolites and colonic metabolites in the overall antioxidant activity associated with coffee consumption is shown. Colonic metabolites such as m-coumaric acid and dihydroferulic acid showed high antioxidant activity. The ability of these compounds to protect human low-density lipoprotein (LDL) oxidation by copper and 2,2'-azobis(2-amidinopropane) dihydrochloride was also explored. 1-Methyluric acid was particularly effective at inhibiting LDL oxidative modification. Different experiments showed that this caffeine metabolite is not incorporated into LDL particles. However, at physiologically relevant concentrations, it was able to delay for more than 13 h LDL oxidation by copper.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antioxidants / pharmacology*
  • Caffeine / metabolism
  • Coffee / chemistry*
  • Colon / metabolism
  • Copper / chemistry
  • Coumaric Acids / pharmacology
  • Humans
  • Lipid Peroxidation / drug effects
  • Lipoproteins, LDL / blood
  • Oxidation-Reduction


  • Antioxidants
  • Coffee
  • Coumaric Acids
  • Lipoproteins, LDL
  • Caffeine
  • Copper
  • ferulic acid