Suberylglycine excretion in the urine from a patient with dicarboxylic aciduria

Suberylglycine (HOOC(CH₂)₆CONHCH₂COOH) was found in the urine from a patient with C₆-C₁₀-ω-dicarboxylic aciduria and unexplained episodes of lethargy and unconsciousness. The total excretion of adipic, suberic and sebacic acid ranged from 0.77 to 1.3 mg/mg creatinine after episodes of acute attack of the disease. Suberylglycine, identified by gas chromatography/mass spectrometry, was repeatedly found in the urine samples. The amount of this conjugate ranged from 0.2 to 0.5 mg/mg creatinine. The precursors of the dicarboxylic acids are suggested to be long chain monocarboxylic acids, oxidized through ω- and β-oxidation to adipic, suberic and sebacic acid. Suberylglycine is subsequently formed by glycine-N-acylase-catalyzed conjugation.