Determination of dicumarol metabolites in bile of rats.

After intravenous administration of dicumarol-14C to rats, the bile excreted over the next 24 hr contained from 32 to 46% of the administered radioactivity. At least three primary metabolites and a small amount of unchanged dicumarol were present in the bile. Over 91% of the primary metabolites was converted to dicumarol and 7-hydroxydicumarol by hydrolysis with beta-glucuronidase. Some primary metabolites were hydrolyzed simply by acidification to pH 3 or by treatment under the acidic conditions utilized in the enzymatic hydrolysis. The three primary metabolites contain carboxylic acid groups, as indicated by their electrophoretic mobility-pH profiles, and some are simple glucuronides of dicumarol and 7-hydroxydicumarol. The possibility that others are derivatives of these compounds in which a coumarin lactone ring is opened cannot be ruled out. When the metabolites released by either acidification or enzymatic hydrolysis were chromatographed in n-butanol-3 M ammonia, artifacts were produced, presumably as a result of decomposition of 7-hydroxydicumarol. The question is raised whether a previously reported metabolite (B055) is an artifact.