title: Chemical Synthesis of the Galacturonic Acid Containing Pentasaccharide Antigen of the O-Specific Polysaccharide of Vibrio cholerae O139 and Its Five Fragments.
abstract: Three pentasaccharides, two tetrasaccharides, and a trisaccharide fragment of the O-specific antigen of Vibrio cholerae O139 were synthesized by applying 1 + 1, 2 + 1, 3 + 1, and 4 + 1 coupling strategies. The most challenging tasks involved were the synthesis of the 1,2-cis-glycosidic linkage between galactose and the linker (spacer) molecule and final purification of the target multicharged substances. Difficulties with final deprotection by hydrogenation/hydrogenolysis caused by the presence of galacturonic acid were overcome by protecting the acid with a group inert to the treatment with hydrogen. Some intermediates described previously as incompletely characterized amorphous materials were obtained in the crystalline condition and were fully characterized for the first time.
authors.affiliation: Section on Carbohydrates, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , 8 Center Drive, Bethesda, Maryland 20892-0815, United States.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Lu
authors.affiliation: Section on Carbohydrates, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , 8 Center Drive, Bethesda, Maryland 20892-0815, United States.
authors.forename: Pavol
authors.initials: P
authors.lastname: Kováč
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003460:Crystallization; D006027:Glycosides / Q000737:chemistry*; D006603:Hexuronic Acids / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry; D019081:O Antigens / Q000737:chemistry*; D009844:Oligosaccharides / Q000737:chemistry*; D014312:Trisaccharides / Q000737:chemistry*; D041242:Vibrio cholerae O139 / Q000737:chemistry*
chemical_list: D006027:Glycosides; D006603:Hexuronic Acids; D019081:O Antigens; D009844:Oligosaccharides; D014312:Trisaccharides; C007819:galacturonic acid; D006859:Hydrogen