L-amino acids (L-AAs) play different important roles in the physiology of all living organisms. Their chiral counterparts, D-amino acids (D-AAs) are increasingly being recognized as essential molecules in many biological systems. Secondary amino acids with cyclic structures, such as prolines, exhibit conformational rigidity and thus unique properties in the structural and protein folding. Despite their widespread occurrence, much less attention was paid to their chiral analysis, particularly when the minor, typically D-enantiomer, is present in low amounts in a complex biological matrix. In this paper, a cost-effective, chiral GC–MS method is described for capillary Chirasil-L-Val separation of nine cyclic secondary amino acid enantiomers with four-, five-, and six-membered rings, involving azetidine-2-carboxylic acid, pipecolic acid, nipecotic acid, proline, isomeric cis/trans 3-hydroxy, 4-hydroxyproline, and cis/trans-5-hydroxy-L-pipecolic acid in the excess of its enantiomeric antipode. The sample preparation involves in-situ derivatization with heptafluorobutyl chloroformate, simultaneous liquid–liquid micro-extraction into isooctane followed by amidation of the arising low-polar derivatives with methylamine, an evaporation step, re-dissolution, and final GC–MS analysis. The developed method was used for analyses of human biofluids, biologically active peptides containing chiral proline constituents, and collagen.

L-氨基酸 (L-AAs) 在所有生物体的生理学中发挥着不同的重要作用。它们的手性对应物 D-氨基酸 (D-AA) 越来越多地被认为是许多生物系统中的必需分子。具有环状结构的二级氨基酸，如脯氨酸，表现出构象刚性，因此在结构和蛋白质折叠中具有独特的性质。尽管它们广泛存在，但对它们的手性分析的关注却少得多，特别是当次要的，通常是 D-对映异构体，在复杂的生物基质中以少量存在时。在本文中，描述了一种具有成本效益的手性 GC-MS 方法，用于毛细管 Chirasil-L-Val 分离具有四、五和六元环的九个环状仲氨基酸对映体，涉及氮杂环丁烷-2-羧酸酸、哌可酸、顺/反3-羟基、4-羟基脯氨酸和顺/反-5-羟基-L-哌啶酸的对映体对映体过量。样品制备包括使用氯甲酸七氟丁酯进行原位衍生，同时进行液-液微萃取到异辛烷中，然后用甲胺酰胺化产生的低极性衍生物，蒸发步骤，重新溶解和最终的 GC-MS 分析。开发的方法用于分析人体生物体液、含有手性脯氨酸成分的生物活性肽和胶原蛋白。