title: [Synthesis of a highly branched nonasaccharide sequence of the "bisected"structure of N-glycoproteins].
abstract: A highly branched nonasaccharide, beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----2)-alpha-D-Manp-(1----3) -[beta-D- Glcp-NAc-(1----4)-[beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----2)-alpha-D- Manp- (1----6)]-beta-D-Manp-(1----4)-D-GlcNAc, that represents the carbohydrate chain of the "bisected" structure of lactosamine-type N-glycoproteins was synthesized by a block synthesis approach. The activated trisaccharide block beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----2)-D-Man was coupled first with the low reactive OH-3 group and, in a second step, with the reactive OH-6 group of the central beta-D-mannopyranosyl residue within the suitably protected trisaccharide block beta-D-GlcpNAc-(1----4)-beta-D-Manp-(1----4)-D-GlcNAc. During these coupling steps, the alpha-glycosidic linkages of D-mannopyranosyl residues were formed without neighboring-group participation, which is only successful by use of the imidate procedure.
authors.affiliation: Institut für Organische Chemie, Universität Hamburg, Bundesrepublik Deutschland.
authors.forename: H
authors.initials: H
authors.lastname: Paulsen
authors.forename: M
authors.initials: M
authors.lastname: Heume
authors.forename: H
authors.initials: H
authors.lastname: Nürnberger
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D055598:Chemical Phenomena; D002621:Chemistry; D006023:Glycoproteins; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000138:chemical synthesis*
chemical_list: D006023:Glycoproteins; D009844:Oligosaccharides; C065125:Galp-GlcpNac-Manp-(GlcpNAc)-(Galp-GlpNAc-Manp)-Manp-GlcNac
vernacular_title: Synthese der verzweigten Nonasaccharid-Sequenz der "bisected" Struktur von N-Glycoproteinen.