title: Synthesis of alpha-(2-->5)Neu5Gc oligomers.
abstract: 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.
authors.affiliation: Institute of Biological Chemistry Academia Sinica, Taipei, Taiwan.
authors.forename: Chien-Tai
authors.initials: CT
authors.lastname: Ren
authors.forename: Chien-Sheng
authors.initials: CS
authors.lastname: Chen
authors.forename: Yi-Ping
authors.initials: YP
authors.lastname: Yu
authors.forename: Yow-Fu
authors.initials: YF
authors.lastname: Tsai
authors.forename: Ping-Yu
authors.initials: PY
authors.lastname: Lin
authors.forename: Yu-Ju
authors.initials: YJ
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Zou
authors.forename: Shih-Hsiung
authors.initials: SH
authors.lastname: Wu
mesh_terms: 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
chemical_list: D001426:Bacterial Proteins; D009438:Neuraminic Acids; D009844:Oligosaccharides; C032592:N-glycolylneuraminic acid; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid