COMPARATIVE DETECTION OF FLUORINATED XENOBIOTICS AND THEIR METABOLITES THROUGH F-19 NMR OR C-14 LABEL IN PLANT-CELLS

The metabolism of a new fluorinated fungicide trifluoromethyl)-2-(3,4- dimethoxyphenyl)benzamide] by Acer pseudoplatanus cells was studied co ncurrently through the use of F-19 NMR and with C-14-labeled compound. Approximately 10 fluorinated compounds were observed by F-19 NMR in t he culture; 5 of them were identified. The detection limit was <1 mu M . 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 NM R signals for the derivatives fairly soluble in this solvent. The meta bolism of the studied compound mostly occurred through ring demethoxyl ation and N-dealkylation. The more lipophilic derivatives diffused int o the culture medium; in contrast, the more hydrophilic ones remained inside the cells. This work shows that the sensitivity and high resolu tion power of liquid F-19 NMR spectroscopy confirm its potential usefu lness to study the metabolism of xenobiotics.