title: Emerging pollutants and plants--Metabolic activation of diclofenac by peroxidases.
abstract: Human pharmaceuticals and their residues are constantly detected in our waterbodies, due to poor elimination rates, even in the most advanced waste water treatment plants. Their impact on the environment and human health still remains unclear. When phytoremediation is applied to aid water treatment, plants may transform and degrade xenobiotic contaminants through phase I and phase II metabolism to more water soluble and less toxic intermediates. In this context, peroxidases play a major role in activating compounds during phase I via oxidation. In the present work, the ability of a plant peroxidase to oxidize the human painkiller diclofenac was confirmed using stopped flow spectroscopy in combination with LC-MS analysis. Analysis of an orange colored product revealed the structure of the highly reactive Diclofenac-2,5-Iminoquinone, which may be the precursor of several biological conjugates and breakdown products in planta.
authors.affiliation: Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstaedter Landstraße 1, D-85764 Neuherberg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Huber
authors.affiliation: School of Science, University of Greenwich, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK.
authors.forename: Martina
authors.initials: M
authors.lastname: Preis
authors.affiliation: School of Science, University of Greenwich, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK.
authors.forename: Patricia J
authors.initials: PJ
authors.lastname: Harvey
authors.affiliation: Technische Universität München, Lehrstuhl für Siedlungswasserwirtschaft, Am Coulombwall, 85748 Garching, Germany.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Grosse
authors.affiliation: Technische Universität München, Lehrstuhl für Siedlungswasserwirtschaft, Am Coulombwall, 85748 Garching, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Letzel
authors.affiliation: Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstaedter Landstraße 1, D-85764 Neuherberg, Germany. Electronic address: peter.schroeder@helmholtz-muenchen.de.
authors.forename: Peter
authors.initials: P
authors.lastname: Schröder
mesh_terms: D065767:Activation, Metabolic; D031215:Armoracia / Q000201:enzymology; D001673:Biodegradation, Environmental; D002851:Chromatography, High Pressure Liquid; D004008:Diclofenac / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D010084:Oxidation-Reduction; D053719:Tandem Mass Spectrometry; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D018508:Water Purification / Q000379:methods*
chemical_list: D004008:Diclofenac; D006735:Horseradish Peroxidase; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Diclofenac; Iminoquinone; LC-MS; Peroxidase; Stopped flow spectroscopy