A facile synthesis of isotope labeled acylcarnitines.

Acylcarnitines are a big family of small molecule metabolites with various acyl groups attached to the hydroxyl moiety of l-carnitine. They are good indicators of multiple metabolic disorders. For instance, the newborn screening panel uses flow injection tandem mass spectrometry to analyze more than 30 different acylcarnitines and amino acids extracted from dried blood spots. A facile approach has been developed for the synthesis of isotope labeled acylcarnitines whose mass shift over their unlabeled counterparts can be any number in the range of 3 to 12 Da. This strategy makes it more convenient to provide authentic internal standards for acylcarnitines profiling analyses, thereby expanding their clinical applications.