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.

中文翻译：

---

同位素标记酰基肉碱的简便合成

酰基肉碱是一大类小分子代谢物，其中各种酰基连接到左旋肉碱的羟基部分。它们是多种代谢紊乱的良好指标。例如，新生儿筛查小组使用流动注射串联质谱分析从干血斑中提取的 30 多种不同的酰基肉碱和氨基酸。已经开发了一种简便的方法来合成同位素标记的酰基肉碱，其在未标记对应物上的质量偏移可以是 3 到 12 Da 范围内的任何数字。这种策略可以更方便地为酰基肉碱谱分析提供真实的内部标准，从而扩大其临床应用。