Synthesis of alpha-(2-->5)Neu5Gc oligomers.
A facile synthesis of the sialic acid oligomers alpha-(2-->5)Neu5Gc (1) is presented. Monosaccharides 2-4 with suitable functionality were used as the building blocks. After selective removal of the paired carboxyl and amine protecting groups, the fully protected oligomers were assembled through consecutive coupling of the building blocks by well established peptide coupling techniques. By this approach, fully protected oligomers as large as an octasaccharide were synthesized. Deprotection of these fully protected oligomers was conducted in two steps (LiCl in refluxing pyridine and 0.1 n NaOH) to afford the desired products in high yield. Enzymatic degradation of the octamer with neuraminidase, monitored by capillary electrophoresis (CE), was also accomplished. The stepwise exo-cleavage adducts were all well separated and identified in the CE spectrum. The strategy described here for solution-phase synthesis also provides the basis for future solid-phase synthesis of poly-alpha-(2-->5)Neu5Gc.
Ren
Chien-Tai
CT
Institute of Biological Chemistry Academia Sinica, Taipei, Taiwan.
Chen
Chien-Sheng
CS
Yu
Yi-Ping
YP
Tsai
Yow-Fu
YF
Lin
Ping-Yu
PY
Chen
Yu-Ju
YJ
Zou
Wei
W
Wu
Shih-Hsiung
SH
D001426:Bacterial Proteins; D019075:Electrophoresis, Capillary; D006868:Hydrolysis; D019158:N-Acetylneuraminic Acid / Q000737:chemistry; D009438:Neuraminic Acids / Q000032:analysis / Q000138:chemical synthesis* / Q000378:metabolism; D009439:Neuraminidase / Q000378:metabolism; D009844:Oligosaccharides / Q000032:analysis / Q000138:chemical synthesis / Q000378:metabolism
D001426:Bacterial Proteins; D009438:Neuraminic Acids; D009844:Oligosaccharides; C032592:N-glycolylneuraminic acid; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid