Yamagaki T, Mitsuishi Y, Nakanishi H
National Institute of Bioscience and Human-Technology, AIST, Ibaraki, Japan.
Biosci Biotechnol Biochem. 1998 Dec;62(12):2470-5. doi: 10.1271/bbb.62.2470.
Highly branched xyloglucan oligosaccharides were analyzed by the post-source decay (PSD) fragmentation method of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). The ratio of [M-Xyl]+ and [M-Gal]+ fragment ion intensities could be used to characterize the degree of Gal substitution at the non-reducing end, because the number of possible chemical species was directly related to their relative ion intensity. The intensity of the [M-Fuc]+ ion was predominantly strong in the fragment spectrum of fucosyl oligosaccharides as the first fragmentation, indicating the fucosyl linkage to be much weaker than the other glycosidic linkages in the MALDI-PSD fragmentation. Setting fragment ion [M-Fuc]+ to the pseudo precursor ion [MF]+, the second fragmentation ions were produced from [MF]+ in the drift region in PSD fragmentation of fucosyl oligosaccharides.
通过基质辅助激光解吸/电离飞行时间质谱（MALDI-TOFMS）的源后衰变（PSD）碎裂方法对高度分支的木葡聚糖寡糖进行了分析。[M-Xyl]+和[M-Gal]+碎片离子强度的比值可用于表征非还原端的半乳糖取代程度，因为可能的化学物种数量与它们的相对离子强度直接相关。在岩藻糖基寡糖的碎片谱中，作为首次碎裂，[M-Fuc]+离子的强度主要很强，这表明在MALDI-PSD碎裂中，岩藻糖基键比其他糖苷键弱得多。将碎片离子[M-Fuc]+设为伪前体离子[MF]+，在岩藻糖基寡糖的PSD碎裂中，在漂移区由[MF]+产生二次碎裂离子。
