To understand the mode of action of bioactive oligosaccharides, such as prebiotics, in-depth knowledge about all structural features, including monosaccharide composition, linkage type, and anomeric configuration, is necessary. Current analytical techniques provide limited information about structural features within complex mixtures unless preceded by extensive purification. In this study, we propose an approach employing cyclic ion mobility spectrometry (cIMS) for the in-depth characterization of oligosaccharides, here demonstrated for disaccharides. We were able to separate galactose and glucose anomers by exploiting the high ion mobility resolution of cIMS. Using the obtained monosaccharide mobilograms as references, we determined the composition and anomeric configuration of 4β-galactobiose by studying the monosaccharide fragments generated by collision-induced dissociation (CID) before the ion mobility separation. Drift times and individual MS² spectra of partially resolved reducing-end anomers of 4β-galactobiose, 4β-galactosylglucose (lactose), and 4β-glucosylglucose (cellobiose) were obtained by deconvolution using CID fragmentation induced in the transfer region between the cIMS cell and TOF analyzer. The composition and anomeric configuration of the reducing end anomers of these disaccharides were identified using cIMS² approaches, where first each anomer was isolated using cIMS and individually fragmented, and the monosaccharide fragments were again separated by cIMS for comparison with monosaccharide standards. With these results we demonstrate the promising application of cIMS for the structural characterization of isomeric oligosaccharides.

中文翻译：

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使用循环离子淌度光谱法和单糖标准品对二糖进行结构表征

为了了解益生元等生物活性寡糖的作用模式，需要深入了解所有结构特征，包括单糖组成、键合类型和端基异构构型。目前的分析技术只能提供有关复杂混合物结构特征的有限信息，除非事先进行大量纯化。在这项研究中，我们提出了一种采用循环离子淌度光谱法 (cIMS) 来深入表征低聚糖的方法，此处针对二糖进行了演示。通过利用 cIMS 的高离子淌度分辨率，我们能够分离半乳糖和葡萄糖端基异构体。以获得的单糖迁移图为参考，我们通过研究离子淌度分离前碰撞诱导解离（CID）产生的单糖片段，确定了4β-半乳二糖的组成和异头构型。 4β-半乳二糖、4β-半乳糖基葡萄糖（乳糖）和 4β-葡萄糖基葡萄糖（纤维二糖）部分解析的还原端异头物的漂移时间和各个 MS ²谱图通过使用 cIMS 细胞和细胞之间转移区域中诱导的 CID 碎片反卷积获得。 TOF 分析仪。使用 cIMS ²方法鉴定这些二糖还原端异头物的组成和异头构型，其中首先使用 cIMS 分离每个异头物并单独片段化，然后再次通过 cIMS 分离单糖片段以与单糖标准品进行比较。通过这些结果，我们证明了 cIMS 在异构寡糖结构表征方面的应用前景。