In high-resolution ion mobility spectrometry-mass spectrometry (IMS-MS)-based separations individual, pure, oligosaccharide species often produce multiple IMS peaks presumably from their α/β anomers, cation attachment site conformations, and/or other energetically favorable structures. Herein, the use of high-resolution traveling wave-based cyclic IMS-MS to systematically investigate the origin of these multiple peaks by analyzing α1,4- and β1,4-linked d-glucose homopolymers as a function of their group I metal adducts is presented. Across varying degrees of polymerization, and for certain metal adducts, at least two major IMS peaks with relative areas that matched the ∼40:60 ratio for the α/β anomers of a reducing-end d-glucose as previously calculated by NMR were observed. To further validate that these were indeed the α/β anomers, rather than other substructures, the reduced versions of several maltooligosaccharides were analyzed and all produced a single IMS peak. This result enabled the discovery of a mobility fingerprint trend: the β anomer was always higher mobility than the α anomer for the cellooligosaccharides, while the α anomer was always higher mobility than the β anomer for the maltooligosaccharides. For maltohexaose, a spurious, high mobility, fourth peak was present. This was hypothesized to potentially be from a highly compacted conformation. To investigate this, α-cyclodextrin, a cyclic oligosaccharide, produced similar arrival times as the high mobility maltohexaose peak. It is anticipated that these findings will aid in the data deconvolution of IMS-MS-based glycomics workflows and enable the improved characterization of biologically relevant carbohydrates.

中文翻译：

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研究 α/β 碳水化合物连接异构体的结构作为 I 族金属加成和聚合度的函数，如循环离子迁移率分离所揭示。

在基于高分辨率离子迁移谱-质谱 (IMS-MS) 的分离中，单个、纯的寡糖种类通常会产生多个 IMS 峰，推测可能来自它们的 α/β 端基异构体、阳离子附着位点构象和/或其他能量有利的结构。在此，使用基于高分辨率行波的循环 IMS-MS 通过分析 α1,4- 和 β1,4-连接的 d-葡萄糖均聚物作为其 I 族金属加合物的函数来系统地研究这些多个峰的起源被表达。在不同的聚合度中，对于某些金属加合物，观察到至少两个主要 IMS 峰的相对面积与之前通过 NMR 计算的还原端 d-葡萄糖的 α/β 异头物的 40:60 比率匹配. 为了进一步验证这些确实是 α/β 异头物，而不是其他亚结构，分析了几种麦芽低聚糖的还原形式，并且都产生了一个单一的 IMS 峰。这一结果使我们发现了一个迁移指纹趋势：对于纤维寡糖来说，β 端基异构体的迁移率总是高于 α 端基异构体，而对于麦芽低聚糖来说，α 端基异构体的迁移率总是高于 β 端基异构体。对于麦芽六糖，存在虚假的、高迁移率的第四个峰。假设这可能来自高度压缩的构象。为了研究这一点，α-环糊精，一种环状寡糖，产生了与高迁移率麦芽六糖峰相似的到达时间。预计这些发现将有助于基于 IMS-MS 的糖组学工作流程的数据解卷积，并能够改进生物相关碳水化合物的表征。