title: Reactivity of catecholamine-driven Fenton reaction and its relationships with iron(III) speciation.
abstract: BACKGROUND
  Fenton reaction is the main source of free radicals in biological systems. The reactivity of this reaction can be modified by several factors, among these iron ligands are important. Catecholamine (dopamine, epinephrine, and norepinephrine) are able to form Fe(III) complexes whose extension in the coordination number depends upon the pH. Fe(III)-catecholamine complexes have been related with the development of several pathologies.
  
  
  METHODS
  In this work, the ability of catecholamines to enhance the oxidative degradation of an organic substrate (veratryl alcohol, VA) through Fenton and Fenton-like reactions was studied. The initial VA degradation rate at different pH values and its relationship to the different iron species present in solution were determined. Furthermore, the oxidative degradation of VA after 24 hours of reaction and its main oxidation products were also determined.
  
  
  RESULTS
  The catecholamine-driven Fenton and Fenton-like systems showed higher VA degradation compared to unmodified Fenton or Fenton-like systems, which also showed an increase in the oxidation state of the VA degradation product. All of this oxidative degradation takes place at pH values lower than 5.50, where the primarily responsible species would be the Fe(III) mono-complex.
  
  
  CONCLUSIONS
  The presence of Fe(III) mono-complex is essential in the ability of catecholamines to increase the oxidative capacity of Fenton systems.
authors.forename: Victoria
authors.initials: V
authors.lastname: Melin
authors.forename: Adolfo
authors.initials: A
authors.lastname: Henríquez
authors.forename: Juanita
authors.initials: J
authors.lastname: Freer
authors.forename: David
authors.initials: D
authors.lastname: Contreras
mesh_terms: D001592:Benzyl Alcohols / Q000737:chemistry*; D002395:Catecholamines / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D010084:Oxidation-Reduction
chemical_list: D001592:Benzyl Alcohols; D002395:Catecholamines; C045076:Fenton's reagent; D005290:Ferric Compounds; D006861:Hydrogen Peroxide; D007501:Iron; C042197:veratryl alcohol
keywords: Catechol; Catecholamines; Dopamine; Epinephrine; Fenton reaction; Fenton-like reaction; Norepinephrine