Czech Academy of Sciences, Biology Centre, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic.
Amino Acids. 2022 May;54(5):687-719. doi: 10.1007/s00726-022-03136-6. Epub 2022 Feb 21.
Naturally occurring secondary amino acids, with proline as the main representative, contain an alpha-imino group in a cycle that is typically four-, five-, and six-membered. The unique ring structure exhibits exceptional properties-conformational rigidity, chemical stability, and specific roles in protein structure and folding. Many proline analogues have been used as valuable compounds for the study of metabolism of both prokaryotic and eukaryotic cells and for the synthesis of compounds with desired biological, pharmaceutical, or industrial properties. The D-forms of secondary amino acids play different roles in living organisms than the L-forms. They have different metabolic pathways, biological, physiological, and pharmacological effects, they can be indicators of changes and also serve as biomarkers of diseases. In the scientific literature, the number of articles examining D-amino acids in biological samples is increasing. The review summarises information on the occurrence and importance of D- and L-secondary amino acids-azetidic acid, proline, hydroxyprolines, pipecolic, nipecotic, hydroxypipecolic acids and related peptides containing these D-AAs, as well as the main analytical methods (mostly chromatographic) used for their enantiomeric determination in different matrices (biological samples, plants, food, water, and soil).
天然存在的仲氨基酸，以脯氨酸为主要代表，在通常为四、五和六元环的环中含有一个α-亚氨基基团。独特的环结构表现出特殊的性质——构象刚性、化学稳定性以及在蛋白质结构和折叠中的特定作用。许多脯氨酸类似物已被用作研究原核和真核细胞代谢以及合成具有所需生物、制药或工业性质的化合物的有价值的化合物。在生物体中，仲氨基酸的 D 型比 L 型发挥不同的作用。它们具有不同的代谢途径、生物学、生理学和药理学作用，它们可以作为变化的指标，也可以作为疾病的生物标志物。在科学文献中，检查生物样品中 D-氨基酸的文章数量正在增加。该综述总结了 D-和 L-仲氨基酸——氮杂环丙酸、脯氨酸、羟脯氨酸、哌啶酸、六氢哌啶酸和含有这些 D-AA 的相关肽的存在和重要性的信息，以及用于在不同基质（生物样品、植物、食品、水和土壤）中对这些 D-AA 进行对映体测定的主要分析方法（主要是色谱法）。
