title: Convergent synthesis of a common pentasaccharide corresponding to the O-antigen of Escherichia coli O168 and Shigella dysenteriae type 4.
abstract: A convenient synthetic strategy of the common acidic pentasaccharide repeating unit corresponding to the O-antigen of enterotoxigenic E. coli O168 and Shigella dysenteriae type 4 has been successfully developed. A stereoselective [2 + 3] block glycosylation method has been exploited to get the target pentasaccharide derivative. Most of the synthetic intermediates were solid and prepared in high yields from commercially available reducing sugars following a series of protection-deprotection reactions. A α-D-mannose moiety has been used as the source of α-D-glucosamine moiety. A late-stage TEMPO mediated selective oxidation reaction finally resulted in the pentasaccharide containing a glucuronic acid unit.
authors.affiliation: Molecular Medicine Division, Bose Institute, P-1/12, C. I. T. Scheme VII M, Kolkata, 700054, India.
authors.forename: Goutam
authors.initials: G
authors.lastname: Guchhait
authors.forename: Anup Kumar
authors.initials: AK
authors.lastname: Misra
mesh_terms: D002240:Carbohydrate Sequence; D004926:Escherichia coli / Q000276:immunology*; D006031:Glycosylation; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D019081:O Antigens / Q000737:chemistry*; D009844:Oligosaccharides / Q000737:chemistry*; D012762:Shigella dysenteriae / Q000276:immunology*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D019081:O Antigens; D009844:Oligosaccharides