Characterization of metabolites of fungicidal cymoxanil in a sensitive strain of Botrytis cinerea.
The metabolism of cymoxanil [1-(2-cyano-2-methoxyiminoacetyl)-3-ethyl urea] by a very sensitive strain of Botrytis cinerea toward this fungicide was studied by using [2-(14)C]-cymoxanil. Labeled cymoxanil was added either in a culture of this strain or in its enzymatic extract. The main metabolites, detected in biological samples, were isolated and identified by mass and NMR spectrometry. Their identification allowed us to show that this strain quickly metabolized cymoxanil according to at least three enzymatic pathways: (i) cyclization leading, after hydrolysis, to ethyl parabanic acid, (ii) reduction giving demethoxylated cymoxanil, and (iii) hydrolysis and reduction followed by acetylation leading to N-acetylcyanoglycine. In a cell-free extract of the same strain, only the first and the second enzymatic reactions, quoted above, occurred. Biological tests showed that, among all the metabolites, only N-acetylcyanoglycine is fungitoxic toward this sensitive strain.
Tellier
Frederique
F
UMR 1290, INRA, route de Saint-Cyr, F-78026 Versailles, France. ftellier@versailles.inra.fr
Fritz
Rene
R
Kerhoas
Lucien
L
Ducrot
Paul-Henri
PH
Einhorn
Jacques
J
Carlin-Sinclair
Abel
A
Leroux
Pierre
P
D000081:Acetamides / Q000378:metabolism*; D000107:Acetylation; D020171:Botrytis / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D002250:Carbon Radioisotopes; D005659:Fungicides, Industrial / Q000378:metabolism*; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010084:Oxidation-Reduction
D000081:Acetamides; D002250:Carbon Radioisotopes; D005659:Fungicides, Industrial; C025644:2-cyano-N-((ethylamino)carbonyl)-2-(methoxyimino)acetamide