Hexa- to tridecasaccharides corresponding to the O-specific polysaccharide (O-SP) of the Gram-negative bacterium Shigella dysenteriae type 1 were synthesized in solution phase. The syntheses utilized tetra-, octa-, and dodecasaccharide intermediates that represent one to three contiguous tetrasaccharide repeating units of the O-SP [Synlett2003, 743]. These compounds were glycosylated with mono-, di-, and trisaccharide trichloroacetamidates, which were synthesized in this study. The excellent stereodirecting effect of 4,6-O-benzophenone ketals in glycosylation reactions of 2-azido-2-deoxy-glucopyranosyl donors was demonstrated. The free oligosaccharides were characterized by (1)H and (13)C NMR spectroscopy and by high-resolution mass spectrometry. The oligosaccharides described herein contain the 5-(methoxycarbonyl)pentyl aglycon for eventual attachment to immunogenic carriers using a recently published protocol [Org. Lett.2005, 70, 6987].
synthesis, oligosaccharide, vaccine, Conjugation, protecting groups, antibacterial, Benzophenone ketal, Benzophenone ketal; Oligosaccharide; Protecting groups; Synthesis; Conjugation; Antibacterial; Vaccine
NCBI PubMed ID: 16650395Journal NLM ID: 0043535Publisher: Elsevier
Correspondence: pozsgayv@mail.nih.gov; vipo@helix.nih.gov
Institutions: Laboratory of Developmental and Molecular Immunity, National Institute of Child Health and Human Development, National Institutes of Health, 31 Center Dr. Rm. 2A29, MSC 2423, Bethesda, MD 20892-2423, USA
Methods: chemical synthesis
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