Abstract: Phosphoglycoproteins are a kind of compounds that have many important biological functions. In order to study the relationship between the structure and the biological functions of these compounds, some core structures(glycosyl-1-phosphoramides) of these compounds were synthesized. Electrospray ionization mass spectrometry(ESI-MS) was used to study the fragmentation characteristics of various types of acetyl protecting mannosyl-1-phosphoramidates. The results show that there are very different characteristics between α- and β- anomeric isomers. The ESI-MS² spectra of the quasi\|molecular ion ［M+Na］⁺ of β-anomeric isomers show characteristic fragment ions at m/z 433, 391 and 371; and the relative abundance of fragment ion ［M-CH₂CHCH₃+Na］⁺ peak is much higher than that of αanomeric isomers. That this characteristic fragmentation should be due to the interaction of the phosphoramide group at the anomeric carbon and the acetyl protecting groups of the hydroxyl groups, especially the acetyl protecting group at C2. Meanwhile, the ESI-MS³ spectrum of fragment ion ［sugar+Na］⁺ m/z 353 of different isomers of acetyl protecting glycosyl-1-phosphoramidates shows the same fragmentation pattern including the loss of molecules of CH_2⁼C=O and AcOH and is not effected by the other position configuration.

Key words: Mannosyl-1-phosphoramidate, ESI-MS, Fragmentation pattern