Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: bacillary dysentery [ICD11:
1A02 
, ICD11:
XN7HG ];
infection due to Shigella flexneri [ICD11:
XN7Y2 ]
The structure was elucidated in this paperNCBI PubMed ID: 26340432Publication DOI: 10.1021/acs.joc.5b01407Journal NLM ID: 2985193RPublisher: Columbus, OH: American Chemical Society
Correspondence: laurence.mulard
pasteur.fr
Institutions: CNRS, UMR5504, F-31400 Toulouse, France, INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse, France, Université de Toulouse, INSA,UPS,INP, LISBP, 135 Avenue de Rangueil, 31077 Toulouse, France, Institut Pasteur, Unité de Chimie des Biomolécules, 28 rue du Dr Roux, 75724, Paris Cedex 15 France, CNRS UMR 3523, Institut Pasteur, 75015 Paris, France
Chemo-enzymatic strategies hold great potential for the development of stereo- and regioselective syntheses of structurally defined bioactive oligosaccharides. Herein, we illustrate the potential of the appropriate combination of a planned chemo-enzymatic pathway and an engineered biocatalyst for the multistep synthesis of an important decasaccharide for vaccine development. We report the stepwise investigation, which led to an efficient chemical conversion of allyl α-d-glucopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→3)-2-deoxy-2-trichlor oacetamido-β-d-glucopyranoside, the product of site-specific enzymatic α-d-glucosylation of a lightly protected non-natural disaccharide acceptor, into a pentasaccharide building block suitable for chain elongation at both ends. Successful differentiation between hydroxyl groups features the selective acylation of primary alcohols and acetalation of a cis-vicinal diol, followed by a controlled per-O-benzylation step. Moreover, we describe the successful use of the pentasaccharide intermediate in the [5 + 5] synthesis of an aminoethyl aglycon-equipped decasaccharide, corresponding to a dimer of the basic repeating unit from the O-specific polysaccharide of Shigella flexneri 2a, a major cause of bacillary dysentery. Four analogues of the disaccharide acceptor were synthesized and evaluated to reach a larger repertoire of O-glucosylation patterns encountered among S. flexneri type-specific polysaccharides. New insights on the potential and limitations of planned chemo-enzymatic pathways in oligosaccharide synthesis are provided.
Shigella flexneri, O-specific polysaccharide, pentasaccharide, vaccine, glycosides, chemical synthesis, type-specific, Glucosyltransferases, Shigella flexneri 2a, chemo-enzymatic, decasaccharide
Structure type: polymer chemical repeating unit ; n=2
Location inside paper: abstract, p.11239, scheme 2, decasaccharide 5
Aglycon: aminoethyl
Compound class: O-polysaccharide
Contained glycoepitopes: IEDB_125613,IEDB_125614,IEDB_127514,IEDB_130687,IEDB_133752,IEDB_133753,IEDB_133754,IEDB_135806,IEDB_135807,IEDB_135808,IEDB_135809,IEDB_135813,IEDB_135817,IEDB_136105,IEDB_137340,IEDB_141807,IEDB_141815,IEDB_141816,IEDB_142488,IEDB_143253,IEDB_144998,IEDB_146664,IEDB_151531,IEDB_153213,IEDB_225177,IEDB_885823,IEDB_983931,SB_192
Methods: 13C NMR, 1H NMR, chemical synthesis, chemical methods, conjugation, HR-MALDI-TOF MS, glucosylation
Synthetic data: chemoenzymatic
Comments, role: dimer of the repeating unit from the O-specific polysaccharide of Sh. flexneri 2a
NCBI Taxonomy refs (TaxIDs): 42897Reference(s) to other database(s): GTC:G13476UX
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
report error