Identification of new medium-chain acylcarnitines present in urine of a patient with medium-chain acyl-CoA dehydrogenase deficiency

Previously undescribed medium-chain acylcarnitines were identified in a urine sample from a patient with medium-chain acyl-CoA dehydrogenase deficiency. These are the 4-methylvaleryl, 4- and 5-methylhexanoyl, 6-methyl-heptanoyl-, 6-methyloctanoyl-, 4,5-dimethylhexanoyl- and 4,7-decadienoyl-carnitines. Their chemical structures were obtained by gas chromatography–mass spectrometry analysis of their fatty acid moieties as picolinyl esters.