Octanoylglucuronide excretion in patients with a defective oxidation of medium-chain fatty acids.
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.
D042964:Acyl-CoA Dehydrogenase; D044944:Acyl-CoA Dehydrogenases / Q000172:deficiency*; D002210:Caprylates / Q000652:urine*; D002331:Carnitine / Q000031:analogs & derivatives / Q000652:urine; D005227:Fatty Acids / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008052:Lipid Metabolism, Inborn Errors / Q000201:enzymology / Q000652:urine*
D002210:Caprylates; D005227:Fatty Acids; C047456:octanoylglucuronide; D044944:Acyl-CoA Dehydrogenases; D042964:Acyl-CoA Dehydrogenase; C008698:octanoylcarnitine; D002331:Carnitine