Cleavage products of lycopene produced by in vitro oxidations: characterization and mechanisms of formation

J Agric Food Chem. 2003 Dec 3;51(25):7318-25. doi: 10.1021/jf034735+.

Abstract

The aim of this study was to produce in vitro oxidation products of lycopene, which could be possible in vivo metabolites. An oxidation of lycopene with potassium permanganate gave a range of lycopene degradation compounds resulting from the oxidative cleavage of one or two carbon-carbon double bonds. Eleven apo-lycopenals/ones and six apo-carotendials were obtained and tentatively characterized by HPLC-DAD-MS. Apo-11-lycopenal and apo-8,6'-carotendial were isolated and characterized by (1)H NMR for the first time. Lycopene was submitted to an oxidation by atmospheric oxygen catalyzed by a metalloporphyrin, a model system of the active center of cytochrome P450 enzymes. (Z)-Isomers, monoxides, and cleavage compounds of (E)-lycopene were formed. We propose a mechanism of oxidation of lycopene by this system.

MeSH terms

  • Carotenoids / chemistry*
  • Chromatography, High Pressure Liquid
  • Lycopene
  • Magnetic Resonance Spectroscopy
  • Mass Spectrometry
  • Metalloporphyrins / chemistry
  • Oxidation-Reduction
  • Oxygen / chemistry
  • Potassium Permanganate / chemistry
  • Ruthenium / chemistry

Substances

  • Metalloporphyrins
  • Potassium Permanganate
  • Carotenoids
  • Ruthenium
  • Oxygen
  • Lycopene