Key Laboratory for Applied Technology of Sophisticated Analytical Instruments of Shandong Province, Shandong Analysis and Test Center, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250014, China; Key Laboratory for Natural Active Pharmaceutical Constituents Research in Universities of Shandong Province, School of Pharmaceutical Sciences, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250014, China.
School of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan, 250355, China.
Anal Chim Acta. 2023 Oct 16;1278:341741. doi: 10.1016/j.aca.2023.341741. Epub 2023 Aug 19.
Carbohydrates play crucial regulatory roles in various physiological and pathological processes. However, the low ionization efficiency and the presence of linkage pattern, monosaccharide composition and anomeric configuration isomers make their in-depth analysis very challenging, especially for heterogeneous biological tissues. In this study, we propose a high-sensitive and isomer-specific imaging approach to visualize the spatial distributions of monosaccharide and disaccharide isomers by integrating chemical derivatization and matrix-assisted laser desorption/ionization tandem mass spectrometry imaging (MALDI-MSI). 2-Pyridinecarbohydrazide (PYD) is developed as a novel derivatization reagent which can not only improves the MS sensitivity of carbohydrates, but also enables the identification and visualization of ketose and aldose monosaccharide isomers, as well as linkage pattern, monosaccharide composition and anomeric configuration disaccharide isomers by mass spectrometry imaging of isomer-specific MS/MS fragment ions. Moreover, we build quantitative MALDI-MS and MALDI-MSI methods for disaccharide isomers based on the diagnostic fragment ions, and good linear relationships could be achieved both in solution and on glass slides. We expect that this study should provide new ideas for in-depth profiling of the spatial signatures of carbohydrates in biological tissues and lay the foundation for a deeper understanding of carbohydrates' structure.
碳水化合物在各种生理和病理过程中起着至关重要的调节作用。然而，由于低离子化效率以及糖苷键的存在、单糖组成和端基异构体的异构形式，使得对其进行深入分析极具挑战性，尤其是对异质生物组织而言。在这项研究中，我们提出了一种高灵敏度和异构体特异性的成像方法，通过化学衍生化和基质辅助激光解吸/电离串联质谱成像（MALDI-MSI）来可视化单糖和二糖异构体的空间分布。我们开发了 2-吡啶甲酰肼（PYD）作为一种新型衍生化试剂，它不仅可以提高碳水化合物的质谱灵敏度，而且还可以通过异构体特异性 MS/MS 碎片离子的质谱成像来识别和可视化酮糖和醛糖单糖异构体，以及糖苷键的存在、单糖组成和端基异构体二糖异构体。此外，我们基于诊断性碎片离子建立了用于二糖异构体的定量 MALDI-MS 和 MALDI-MSI 方法，在溶液和载玻片上均能得到良好的线性关系。我们期望这项研究能为深入分析生物组织中碳水化合物的空间特征提供新的思路，并为深入了解碳水化合物的结构奠定基础。
