title: Biodegradation pathway of mesotrione: complementarities of NMR, LC-NMR and LC-MS for qualitative and quantitative metabolic profiling.
abstract: Enhanced knowledge of pesticide transformation products formed in the environment could lead to both accurate estimates of the overall effects of these compounds on environmental ecosystems and human health and improved removal processes. These compounds can present chemical and environmental behaviours completely different from the starting active ingredient. The difficulty lies on their identification or/and their quantification due to the lack of analytical reference standards. In this context, ex situ Nuclear Magnetic Resonance (NMR) and Liquid Chromatography-NMR (LC-NMR) were used as complementary tools to LC-Mass Spectrometry (MS) to define the metabolic pathway of mesotrione, an emergent herbicide, by the bacterial strain Bacillus sp. 3B6. The complementarities of ex situ and LC-NMR allowed us to unambiguously identify six metabolites whereas the structures of only four metabolites were suggested by LC-MS. The presence of a new metabolic pathway was evidenced by NMR. These results demonstrate that NMR and LC-NMR spectroscopy provided unambiguous structural information for xenobiotic metabolic profiling, even at moderate magnetic field and allowed direct absolute quantification despite the lack of commercial or synthetic standards, required for LC-MS techniques.
authors.affiliation: Clermont Université, Université Blaise Pascal, Laboratoire de Synthèse et Etude de Systèmes à Intérêt Biologique, 63000 Clermont-Ferrand, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Durand
authors.forename: Martine
authors.initials: M
authors.lastname: Sancelme
authors.forename: Pascale
authors.initials: P
authors.lastname: Besse-Hoggan
authors.forename: Bruno
authors.initials: B
authors.lastname: Combourieu
mesh_terms: D001407:Bacillus / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002853:Chromatography, Liquid / Q000379:methods*; D003512:Cyclohexanones / Q000737:chemistry / Q000378:metabolism*; D004785:Environmental Pollutants / Q000737:chemistry / Q000378:metabolism; D006540:Herbicides / Q000737:chemistry / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods*; D053858:Metabolic Networks and Pathways
chemical_list: D003512:Cyclohexanones; D004785:Environmental Pollutants; D006540:Herbicides; C432907:mesotrione