Comparative Detection of Fluorinated Xenobiotics and Their Metabolites through ¹⁹F NMR or ¹⁴C Label in Plant Cells

Abstract

The metabolism of a new fluorinated fungicide [N-ethyl-N-methyl-4-(trifluoromethyl)-2-(3,4-dimethoxyphenyl)benzamide] by Acer pseudoplatanus cells was studied concurrently through the use of 19F NMR and with 14C-labeled compound. Approximately 10 fluorinated compounds were observed by 19F NMR in the culture; 5 of them were identified. The detection limit was <1 μM. Methanol appeared to be a useful solvent as it was able to dissolve the lipophilic active ingredient as well as the more polar derivatives. However, the use of chloroform allowed a better separation of the NMR signals for the derivatives fairly soluble in this solvent. The metabolism of the studied compound mostly occurred through ring demethoxylation and N-dealkylation. The more lipophilic derivatives diffused into the culture medium; in contrast, the more hydrophilic ones remained inside the cells. This work shows that the sensitivity and high resolution power of liquid 19F NMR spectroscopy confirm its potential usefulness to study the metabolism of xenobiotics. Keywords: Acer pseudoplatanus L.; 19F NMR; fungicide; metabolization; plant cells

19F NMR applications in chemical biology

“…The degradation of the fluorinated pesticides N-ethyl-Nmethyl-4-(trifluoromethyl)-2-(3,4-dimethoxyphenyl) benzamide (fungicide) and isoxaflutole (herbicide) in Acer pseudoplantus by was evaluated using 19 F NMR, and some of the fluorometabolites could be identified from their chemical shifts [20,21].…”

Degradation of 4-Fluorobiphenyl by Mycorrhizal Fungi as Determined by 19 F Nuclear Magnetic Resonance Spectroscopy and 14 C Radiolabelling Analysis

“…Under the conditions used in this study T. fibrillosa and some other species degraded 4FBP. 14 C-HPLC profiles indicated that there were four major biotransformation products, whereas 19 F NMR showed that there were six major fluorine-containing products. We confirmed that 4-fluorobiphen-4-ol and 4-fluorobiphen-3-ol were two of the major products formed, but no other products were conclusively identified.…”

“…Thus, it is important to determine the fate and behavior of these compounds in suitable model terrestrial systems. 19 F nuclear magnetic resonance (NMR) spectroscopy is a technique which potentially allows workers to study such compounds in a nondestructive fashion. This technique is relatively sensitive (detection limit, ca.…”

“…Ͻ50 ng/ ml at 9.4T) and has been used to monitor the metabolic fates of fluorinated compounds in mammals (2,24). More recently, 19 F NMR spectroscopy has been used to study the degradation of fluorinated agrochemicals (1,9,14,18,19). In the present study we examined the ability of ecto-and ericoid mycorrhizal fungi to degrade fluorinated biphenyls in batch cultures.…”

Pesticides

“…Carbendazim and imazalil were chromatographed in fruits (310). One-and two-dimensional TLC were used (313). Photodegradation of the azole fungicide briadimefon was investigated (312).…”