Metabolism of Terephthalic Acid. III. Absorption of Terephthalic Acid from Gastrointestinal Tract and Detection of Its Metabolites

The absorption of terephthalic acid (TPA) from gastrointestinal tract and its metabolites in urine were studied with radioactive TPA (carboxyl-14C compound). Terephthalic acid was absorbed mainly from stomach and small intestine and partly from caecum and large intestine. The administered TPA was excreted almost quantitatively in urine within 24 hr. after the administration, and carbon dioxide as the cleavaged product was not found in the expired air. Examinations by thin-layer chromatography and autoradiography technique failed to detect any metabolite in urine. It was concluded that the administered TPA is not metabolized in body and almost all of it is excreted intact in urine.