Subject(s)
Phenylpropionates/metabolism , Acyl-CoA Dehydrogenase , Acyl-CoA Dehydrogenase, Long-Chain , Administration, Oral , Child , Dicarboxylic Acids/metabolism , Fatty Acid Desaturases/deficiency , Fatty Acid Desaturases/genetics , Fatty Acids/metabolism , Female , Glycine/metabolism , Humans , Infant , Infant, Newborn , Male , Mass Spectrometry , Metabolism, Inborn Errors/diagnosis , Phenylpropionates/urineABSTRACT
Octanoyl-beta-D-glucuronide was identified in the urine of five patients with hypoketotic hypoglycemia and dicarboxylic aciduria due to a defective beta-oxidation of medium-chain fatty acids. Two subjects who ingested large amounts of medium-chain triglycerides also excreted large amounts of the glucuronide. The substance was extracted from the urine with ethyl acetate and analyzed by: (1) gas chromatography/mass spectrometry (GC-MS) of the trimethylsilyl derivative and (2) preparative one-dimensional thin-layer chromatography followed by enzymatic hydrolysis with beta-glucuronidase and again GC-MS. A quantitative analysis was performed indirectly by measuring the urinary bound octanoate after the removal of octanoylcarnitine. Octanoylglucuronide represents an additional mechanism for the detoxification of octanoate; its formation may be of help for the maintenance of carnitine homeostasis in patients with medium-chain acyl-CoA dehydrogenase deficiency.
