An NMR study of the metabolic fate of 2-, 3- and 4-fluorobenzyl alcohols in the rat: detection of N-acetylcysteinyl conjugates as minor metabolites in urine.

Following the administration of 2-, 3- and 4-fluorobenzyl alcohols, the major metabolites detected in urine corresponded to the glycine conjugates of the corresponding benzoic acids. Little, or no, unchanged parent compound was detected in the samples. In addition to glycine-conjugated benzoic acids, a small proportion of the urinary metabolites for each of the fluorobenzyl alcohols was found to correspond to N-acetylcysteinyl conjugate. These were probably formed as the result of the production of a reactive sulphate ester during metabolism. The overall urinary recoveries of metabolites for the 2- and 3-fluorobenzyl alcohols were lower than that observed for the corresponding benzoic acids whilst that for 4-fluorobenzyl alcohol was similar.