The metabolism of alpha-aminobenzo(b)thiophene-3-propionic acid (the sulfur analog of tryptophan) in the rat.

The biotransformation of 3H-labeled alpha-aminobenzo[b]thiophene-3-propionic acid (the sulfur analog of tryptophan) was investigated in rats. Forty-eight hours after ip administration, 80% of the radioactive dose was recovered in the urine and 5% in the feces; tissue levels of radioactivity accounted for the remainder of the administered dose. The urinary metabolites were identified by a combination of thin-layer chromatography, gas chromatography, and gas chromatography-mass spectrometry, and were quantitated by thin-layer chromatography and liquid-scintillation counting to give, as percentages of the administered dose, unchanged alpha-aminobenzo[b]thiophene-3-propionic acid (20.6%), benzo[b]thiophene-3-acetic acid (1.3%), benzo[b]thiophene-3-pyruvic acid (14.2%), benzo[b]thiophene-3-lactic acid (4.9%), and N-(benzo[b]thiophene-3-acetyl)glycine (46.2%).