Yamagaki T, Nakanishi H
National Institute of Bioscience and Human-Technology, AIST, Ibaraki, Japan.
Rapid Commun Mass Spectrom. 1998;12(16):1069-74. doi: 10.1002/(SICI)1097-0231(19980831)12:16<1069::AID-RCM291>3.0.CO;2-J.
The isomeric sugar branched beta-cyclodextrin (CD) derivatives (Glc-beta CD, Gal-beta CD, and Man-beta CD) were analyzed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. In the MALDI post-source decay (PSD) fragmentation of Glc-beta CD, Gal-beta CD and Man-beta CD, the fragment ions of [M-Glc]+, [M-Gal]+ and [M-Man]+ were produced by the one-site cleavage of the alpha 1-6 glycosidic linkage at the branch (Y-type fragmentation). The abundances of [M-Gal]+ ions were much higher than that of [M-Man]+. These results indicated that Glc-beta CD and Gal-beta CD were distinguishable from Man-beta CD and that Y-type fragmentations of the branched glycosidic linkage at the glycosyl donors of alpha-D-Glc and alpha-D-Gal were more predominant than that at the glycosyl donor of alpha-D-Man by MALDI-PSD fragment analysis. It was concluded that the abundances of PSD fragment ions depended on the stereochemistry of the glycosyl donors in the cleavage of the glycosidic linkage of the oligosaccharides in MALDI-TOF mass spectra.
采用基质辅助激光解吸/电离飞行时间（MALDI-TOF）质谱法对异构糖支链β-环糊精（CD）衍生物（葡萄糖-β-CD、半乳糖-β-CD和甘露糖-β-CD）进行了分析。在葡萄糖-β-CD、半乳糖-β-CD和甘露糖-β-CD的MALDI源后衰变（PSD）碎裂过程中，[M-葡萄糖]+、[M-半乳糖]+和[M-甘露糖]+的碎片离子是由支链处α1-6糖苷键的单点裂解产生的（Y型碎裂）。[M-半乳糖]+离子的丰度远高于[M-甘露糖]+。这些结果表明，葡萄糖-β-CD和半乳糖-β-CD与甘露糖-β-CD可区分开来，并且通过MALDI-PSD碎片分析，α-D-葡萄糖和α-D-半乳糖糖基供体处支链糖苷键的Y型碎裂比α-D-甘露糖糖基供体处更为显著。得出的结论是，在MALDI-TOF质谱中，PSD碎片离子的丰度取决于寡糖糖苷键裂解中糖基供体的立体化学。
