Klebsiella pneumoniae is a Gram-negative pathogenic bacterium that emerges a challenge for modern medicine due to intensively rising multi-drug resistance. Polysaccharides linked to the core region of LPS O-chains represent promising targets for development vaccines for immunoprophylaxis or immunotherapy of K. pneumoniae-caused diseases. The O-antigens of the most prevalent O1 serotype are built up from galactan I, galactan II and galactan III.
Herein we report the synthesis of biotinylated 2-,4- and 6-saccharides 1‑6 structurally related both to galactan I and galactan II (scheme 1). For the assembling of target oligosaccharides convergent strategy based on disaccharide donors 9 and 11 was used. The key step for preparation of galactofuranose-containing synthetic blocks was pyranoside-into-furanoside (PIF) rearrangement [1].
Biotinylated oligosaccharides 1-6 were immobilized on the surface of streptavidin coated plates to form glycoarray which was applied for screening of sera against K. pneumoniae. The obtained results demonstrate the applicability of such a glycoarray-based assay for typing Klebsiella strains belonging to most frequent O1 serogroup [2].
Scheme 1. Key blocks and stages in the synthesis of galactan I and galactan II related oligosaccharides.
This work was supported by RSF grant 19-73-30017.
- V.B. Krylov, D.A. Argunov, D.Z. Vinnitskiy, S.A. Verkhnyatskaya, A.G. Gerbst, N.E. Ustyuzhanina, A.S. Dmitrenok, J. Huebner, O. Holst, H.-C. Siebert, N.E. Nifantiev, Chem. Eur. J., 2014, 20, 16516-16522.
- D.A. Argunov, A.S. Trostianetskaia, V.B. Krylov, E.A. Kurbatova, N.E. Nifantiev, Eur. J. Org. Chem., 2019, in press.
