Biotransformation of the triketone herbicide mesotrione by a Bacillus strain. Metabolite profiling using liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry.
The metabolic pathway involved in the biotransformation of the herbicide mesotrione by the bacterial strain Bacillus sp. 3B6 was investigated by a reliable liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry (LC/ESI-QTOF-MS) method. The LC/ESI-MS method, both in positive and negative mode, with the assistance of MS(2) fragments and isotopic pattern analyses, allowed us to identify five metabolites. This work constitutes the first complete monitoring of mesotrione degradation kinetics. Among the transformation products found by both techniques, one was formed by intramolecular cyclization between a hydroxylamine and a keto function, which is quite a rare biological reactivity process. For each identified metabolite, a fragmentation pathway is proposed for negative and positive mode.
Durand
Stéphanie
S
Laboratoire de Synthèse et Etude de Systèmes à Intérêt Biologique, UMR 6504 CNRS, Université Blaise Pascal, 63177 Aubière Cedex, France.
Légeret
Bertrand
B
Martin
Anne-Sophie
AS
Sancelme
Martine
M
Delort
Anne-Marie
AM
Besse-Hoggan
Pascale
P
Combourieu
Bruno
B
D001407:Bacillus / Q000378:metabolism*; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003512:Cyclohexanones / Q000737:chemistry / Q000378:metabolism*; D006540:Herbicides / Q000737:chemistry / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D003512:Cyclohexanones; D006540:Herbicides; C432907:mesotrione