Studies on the Metabolism of Naturally Occurring Coumarins. VI. Urinary Metabolites of o-Coumaric Acid and Melilotic Acid

抄録

A study on the metabolic fate of o-coumaric acid and melilotic acid has been carried out. The urinary metabolites after o-coumaric acid dosing were determined to consist of unchanged o-coumaric acid (20.22% of dose), o-coumaric acid glucuronide (3.45%), o-coumaroylglycine (11.06%), melilotic acid (8.18%), umbelliferone (1.92%), umbelliferone glucuronide (2.62%), and coumarin (0.96%). Using paper chromatography, the presence of 4-hydroxycoumarin and melilotoylglycine was detected, but 3-hydroxycoumarin was not found. Coumarin and umbelliferone were found in the urine after o-coumaric acid dosing. A cis-trans transformation might be involved in the metabolic process. On dosing melilotic acid, unchanged melilotic acid, o-coumaric acid, melilotoylglycine, o-coumaroylglycine, umbelliferone, 4-hydroxycoumarin, coumarin, and dihydrocoumarin were detected in the urine. Biochemical transformations of o-coumaric and melilotic acids as well as that of coumarin and dihydrocoumarin were discussed.