N-glycans that are fluorescently tagged by glycosylamine acylation have become a promising way for glycan biomarker discovery. Here, we describe a simple and rapid method using Fmoc N-hydroxysuccinimide ester (Fmoc-OSu) to label N-glycans by reacting with their corresponding intermediate glycosylamines produced by microwave-assisted deglycosylation. After optimizing reaction conditions, this derivatization reaction can be effectively achieved under 40 °C for 1 h. Moreover, the comparison of fluorescent intensities for Fmoc-OSu, Fmoc-Cl and 2-AA labeling strategies were also performed. Among which, the fluorescent intensities of Fmoc-OSu labeled glycan derivatives were approximately 5 and 13 times higher than that labeled by Fmoc-Cl and 2-AA respectively. Furthermore, the developed derivatization strategy has also been applied for analyzing serum N-glycans, aiming to screen specific biomarkers for early diagnosis of lung squamous cell cancer. More interestingly, the preparation of free reducing N-glycan standards have been achieved by the combination of HPLC fraction of Fmoc labeled glycan derivatives and Fmoc releasing chemistry. Overall, this proposed method has the potential to be used in functional glycomic study.

中文翻译：

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Fmoc N-羟基琥珀酰亚胺酯：在 N-聚糖分析中的简便多功能作用

由糖胺酰化荧光标记的 N-聚糖已成为发现聚糖生物标志物的一种有前途的方法。在这里，我们描述了一种简单快速的方法，使用 Fmoc N-羟基琥珀酰亚胺酯 (Fmoc-OSu) 通过与微波辅助去糖基化产生的相应中间体糖胺反应来标记 N-聚糖。优化反应条件后，该衍生反应可在40℃下1h有效实现。此外，还对 Fmoc-OSu、Fmoc-Cl 和 2-AA 标记策略的荧光强度进行了比较。其中，Fmoc-OSu标记的聚糖衍生物的荧光强度分别比Fmoc-Cl和2-AA标记的荧光强度高约5倍和13倍。此外，开发的衍生化策略也已应用于分析血清 N-聚糖，旨在筛选用于肺鳞状细胞癌早期诊断的特定生物标志物。更有趣的是，游离还原 N-聚糖标准品的制备是通过 Fmoc 标记聚糖衍生物的 HPLC 级分和 Fmoc 释放化学的组合实现的。总的来说，这种提出的方​​法有可能用于功能糖组学研究。