title: Synthesis of sulfated and phosphorylated glycopeptides from the carbohydrate-protein linkage region of proteoglycans.
abstract: The synthesis of the tetrasaccharide dipeptide beta-D-GlcpA-(1-->3)-beta-D-Galp4SO3Na-(1-->3)-beta-D-Galp-( 1-->4)-beta-D-Xylp- (1-->O)-L-Ser-Gly was achieved by coupling a suitably protected tetrasaccharide trichloroacetimidate, built up from the nonreducing end by the stepwise addition of monosaccharide units, to the protected dipeptide Z-L-Ser-Gly-OBn. Sulfation at O-4 of the second D-Gal unit and complete deprotection afforded the target molecule in high yield. Its phosphorylated analogue beta-D-GlcpA-(1-->3)-beta-D-Galp-(1-->3)-beta-D-Galp-(1-->4)-beta- D-Xylp2PO3Na2 - (1-->O)-L-Ser-Gly was synthesized by coupling a protected trisaccharide trichloroacetimidate to the 2,3-O-isopropylidene derivative of Z-(D-Xyl-)L-Ser-Gly-OBn. Hydrolysis of the O-isopropylidene group, regioselective acetylation at O-3 of the O-Xyl unit, and phosphorylation at O-2 followed by complete deprotection gave the phosphorylated tetrasaccharide dipeptide in high yield. These structures are found in the carbohydrate-protein linkage region of several proteoglycans.
authors.affiliation: Laboratoire de Biochimie Structurale, U.R.A. 499, U.F.R. Faculté des Sciences, Université d'Orléans, France.
authors.forename: S
authors.initials: S
authors.lastname: Rio
authors.forename: J M
authors.initials: JM
authors.lastname: Beau
authors.forename: J C
authors.initials: JC
authors.lastname: Jacquinet
mesh_terms: D002240:Carbohydrate Sequence; D004151:Dipeptides / Q000138:chemical synthesis; D006020:Glycopeptides / Q000138:chemical synthesis*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000138:chemical synthesis; D010755:Organophosphates / Q000138:chemical synthesis; D011509:Proteoglycans / Q000737:chemistry*; D013463:Sulfuric Acid Esters / Q000138:chemical synthesis
chemical_list: D004151:Dipeptides; D006020:Glycopeptides; D009844:Oligosaccharides; D010755:Organophosphates; D011509:Proteoglycans; D013463:Sulfuric Acid Esters