title: Stereoselective synthesis of a blood group A type glycopeptide present in human blood mucin.
abstract: N,N-Dimethyl-O-(2-acetamido-2-deoxy-alpha-D-galactopyranosyl)-(1-->3)-O- [(alpha-L-fucopyranosyl)-(1-->2)]-O-(beta-D-galactopyranosyl)-(1-->3)-O- (2-acetamido-2-deoxy-alpha-D-galactopyranosyl)-(1-->3)-L-serine, a core I glycotetraosyl peptide structure and a predominant substructure in complex glycan-glycoproteins present in human blood group A ovarian mucin, was synthesized for the first time. The title compound was synthetically accomplished via the following key manoeuvres: regio- and stereo-controlled construction of the alpha-GalNAc-(1-->3)-Gal synthon, stereoselective glycosylation generating a alpha-GalN3-(1-->3)-Ser glycopeptide synthon and alpha-selective fucosylation towards an acceptor which was derived from glycosylation of the latter two synthons. An alternative route to that of the latter, to synthesize a fully protected equivalent of the title compound, involving the coupling of a alpha-GalNAc-(1-->3)-beta-Gal-(1-->3)-GalN3X synthon to an aglycon serine derivative, is described herein.
authors.affiliation: Exploratory Research Laboratories, Sankyo Co. Ltd., Tokyo, Japan.
authors.forename: W M
authors.initials: WM
authors.lastname: Macindoe
authors.forename: H
authors.initials: H
authors.lastname: Ijima
authors.forename: Y
authors.initials: Y
authors.lastname: Nakahara
authors.forename: T
authors.initials: T
authors.lastname: Ogawa
mesh_terms: D000017:ABO Blood-Group System / Q000737:chemistry*; D000116:Acetylgalactosamine / Q000737:chemistry; D002240:Carbohydrate Sequence; D005643:Fucose / Q000737:chemistry; D005690:Galactose / Q000737:chemistry; D006020:Glycopeptides / Q000138:chemical synthesis* / Q000737:chemistry; D006801:Humans; D008969:Molecular Sequence Data; D009077:Mucins / Q000097:blood / Q000737:chemistry*; D009844:Oligosaccharides / Q000737:chemistry; D012694:Serine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000017:ABO Blood-Group System; D006020:Glycopeptides; D009077:Mucins; C094072:N,N-dimethyl-O-(2-acetamido-2-deoxygalactopyranosyl)-(1-3)-O-(fucopyranosyl)-(1-2)-O-(galactopyranosyl)-(1-3)-O-(2-acetamido-2-deoxygalactopyranosyl)-(1-3)-serine; D009844:Oligosaccharides; D005643:Fucose; D012694:Serine; D000116:Acetylgalactosamine; D005690:Galactose