Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, Station-6, 1015 Lausanne, Switzerland.
Université de Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR-UMR 6226, F-35000 Rennes, France.
Anal Chem. 2020 Nov 3;92(21):14624-14632. doi: 10.1021/acs.analchem.0c03122. Epub 2020 Oct 14.
Biological functionality of isomeric carbohydrates may differ drastically, making their identifications indispensable in many applications of life science. Because of the large number of isoforms, structural assignment of saccharides is challenging and often requires a use of different orthogonal analytical techniques. We demonstrate that isomeric carbohydrates of any isoforms can be distinguished and quantified using solely the library-based method of 2D ultraviolet fragmentation spectroscopy-mass spectrometry (2D UV-MS) of cold ions. The two-dimensional "fingerprint" identities of UV transparent saccharides were revealed by photofragmentation of their noncovalent complexes with aromatic molecules. We assess the accuracy of the method by comparing the known relative concentrations of isomeric carbohydrates mixed in solution with the concentrations that were mathematically determined from the measured in the gas-phase fingerprints of the complexes. For the tested sets with up to five isomers of di- to heptasaccharides, the root-mean-square deviation of 3-5% was typically achieved. This indicates the expected level of accuracy in analysis of unknown mixtures for isomeric carbohydrates of similar complexity.
异构体碳水化合物的生物学功能可能有很大差异，这使得它们的鉴定在生命科学的许多应用中不可或缺。由于异构体的数量众多，糖的结构分配具有挑战性，通常需要使用不同的正交分析技术。我们证明，仅使用基于文库的二维紫外碎裂光谱-质谱（2D UV-MS）对冷离子的方法，就可以区分和定量任何异构体的异构体碳水化合物。通过芳香族分子与非共价配合物的光碎裂，揭示了紫外透明糖的二维“指纹”特征。我们通过将溶液中混合的已知相对浓度的异构体碳水化合物与从配合物的气相指纹中测量的浓度进行数学计算来评估该方法的准确性。对于测试的二糖至七糖的五个异构体，通常可以达到 3-5%的均方根偏差。这表明在分析类似复杂程度的未知异构体碳水化合物混合物时，预期的准确性水平。
