Windwarder Markus, Figl Rudolf, Svehla Elisabeth, Mócsai Réka Tünde, Farcet Jean-Baptiste, Staudacher Erika, Kosma Paul, Altmann Friedrich
Department of Chemistry, University of Natural Resources and Life Sciences, Vienna; Muthgasse 18, 1190 Vienna, Austria.
Department of Chemistry, University of Natural Resources and Life Sciences, Vienna; Muthgasse 18, 1190 Vienna, Austria.
Anal Biochem. 2016 Dec 1;514:24-31. doi: 10.1016/j.ab.2016.09.008. Epub 2016 Sep 14.
Analysis of the monosaccharides of complex carbohydrates is often performed by liquid chromatography with fluorescence detection. Unfortunately, methylated sugars, unusual amino- or deoxysugars and incomplete hydrolysis can lead to erroneous assignments of peaks. Here, we demonstrate that a volatile buffer system is suitable for the separation of anthranilic acid labeled sugars. It allows off-line examination of peaks by electrospray mass spectrometry. Approaches towards on-line mass spectrometric detection using reversed-phase or porous graphitic carbon columns fell short of achieving sufficient separation of the relevant isobaric sugars. Adequate chromatographic performance for isomeric sugars was achieved with reversed-phase chromatography of "hyper"-methylated anthranilic acid-labeled monosaccharides. Deuteromethyl iodide facilitates the discovery of naturally methylated sugars and identification of their parent monosaccharide as demonstrated with N-glycans of the snail Achatina fulica, where two thirds of the galactoses and a quarter of the mannoses were methylated.
复合碳水化合物中单糖的分析通常采用液相色谱-荧光检测法。不幸的是，甲基化糖、特殊的氨基糖或脱氧糖以及不完全水解会导致峰的错误归属。在此，我们证明了一种挥发性缓冲体系适用于邻氨基苯甲酸标记糖的分离。它允许通过电喷雾质谱对峰进行离线检测。使用反相或多孔石墨化碳柱进行在线质谱检测的方法未能实现相关等压糖的充分分离。通过“超”甲基化邻氨基苯甲酸标记单糖的反相色谱法，实现了同分异构糖的充分色谱性能。如用福寿螺的N-聚糖所证明的，碘代氘代甲烷有助于发现天然甲基化糖并鉴定其母体单糖，其中三分之二的半乳糖和四分之一的甘露糖被甲基化。
