A subclass of the sialic acid family consists of intramolecular lactones that may function as key indicators of physiological and pathological states. However, the existence of these compounds in free form is highly improbable, since they are unlikely to exist in an aqueous solution due to their lability. Current analytical method used to detect them in biological fluids has not recognized their reactivity in solution and is prone to misidentification. However, recent advances in synthetic methods for 1,7-lactones have allowed the preparation of these sialic acid derivatives as authentic reference standards. We report here the development of a new HPLC–MS method for the simultaneous detection of the 1,7-lactone of N-acetylneuraminic acid, its γ-lactone derivative, and N-acetylneuraminic acid that overcomes the limitations of the previous analytical procedure for their identification.

唾液酸家族的一个亚类由分子内酯组成，可作为生理和病理状态的关键指标。然而，这些化合物以游离形式存在的可能性极低，因为它们由于不稳定而不太可能存在于水溶液中。目前用于在生物体液中检测它们的分析方法尚未识别出它们在溶液中的反应性，并且容易出现错误识别。然而，1,7-内酯合成方法的最新进展使得这些唾液酸衍生物的制备成为可靠的参考标准。我们在此报告开发了一种新的 HPLC-MS 方法，用于同时检测N-乙酰神经氨酸的 1,7-内酯、其 γ-内酯衍生物和N- 乙酰神经氨酸，克服了先前分析程序对其鉴定的局限性。