Metabolism of Hymexazol, 3-Hydroxy-5-methylisoxazole,in the Rats

Excretion, distribution and metabolism of the fungicide, hymexazol, (3-hydroxy-5-methylisoxazole), labeled with carbon-14 were examined after administration of a single oral dose to Wistar-strain rats. Hymexazol was rapidly absorbed and distributed in the tissues. During 96 hr, 97% of the total radioactivity was excreted in the urine and 0.89% in the feces, and 0.86% was found in the expired gasses for 24 hr. Two metabolites were detected in the urine, whose chemical structures were determined as 3-(β-d-glucopyranuronosyloxy)-5- methylisoxazole and 5-methyl-3-isoxazolyl sulfate.