[Isolation and identification of some metabolites of mephenoxalone (Control-OM) from human urine (author's transl)].

Mephenoxalone (5-(o-methoxyphenoxymethyl)-2-oxazolidone) is degraded by various routes in the human, and some is excreted unchanged. In the metabolism of mephenoxalone, the phenoxymethyl ether bond is cleaved; thus o-methoxyphenol (metabolite I) was identified in urine, and 3-amino-1,2-propanediol (IIa) was found after alkaline hydrolysis. Hydroxylation of the benzene ring produces a phenolic hydroxymephenoxalone (metabolite III), and demethylation converts mephenoxalone into demethylmepheonxalone (metabolite IV). Opening of the oxazolidone ring leads to the production of 1-(o-methoxyphenoxy)-3-aminopropane-2-ol(metabolite V). Urine contains two further substances: 1-(o-hydroxyphenoxy)-3-aminopropene (metabolite VI) and dehydromephenoxalone (metabolite VII). Metabolite VI may be an artefact. Compounds III, IV and VII could only be detected after acid hydrolysis and enzymic cleavage with beta-glucuronidase/aryl sulphatase, whereas V and VI were detected only after acid hydrolysis. Thin layer chromatography revealed three further metabolites, which were not identified.