Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Aug 21:21:1671-1677.
doi: 10.3762/bjoc.21.131. eCollection 2025.

Structural analysis of stereoselective galactose pyruvylation toward the synthesis of bacterial capsular polysaccharides

Tsun-Yi Chiang  1 , Mei-Huei Lin  1 , Chun-Wei Chang  1 , Jinq-Chyi Lee  2 , Cheng-Chung Wang  1   3
Affiliations

Structural analysis of stereoselective galactose pyruvylation toward the synthesis of bacterial capsular polysaccharides

Tsun-Yi Chiang et al. Beilstein J Org Chem. .

Abstract

Pyruvate ketal is a biologically essential moiety due to its key role as an intermediate in metabolic pathways, serving as a key precursor for the synthesis of various essential biomolecules in organisms. However, the R/S stereochemistry of pyruvate ketal is difficult to control through chemical methods. In this study, the acid-labile pyruvate ketal linked to the 4- and 6-positions of galactose was cautiously constructed, and the X-ray analysis of the R-configured product was successfully obtained. Subsequently, the compound was used for the synthesis of zwitterionic polysaccharide A1 (PS A1) precursor, and a clear structural elucidation was applied by using nuclear magnetic resonance and X-ray.

Keywords: capsular polysaccharides; carbohydrates; diastereochemistry; glycosylation; pyruvate ketals.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Pyruvylated galactose on bacterial polysaccharides PS A1 (1), 1.15 EPS (2) and Rhizobium leguminosarum bv. viciae VF39 EPS (3).
Figure 2
Figure 2
(a) Oak Ridge Thermal Ellipsoid Plot view of the X-ray crystal structure of pyruvylated galactose 6. (b) Hydrogen-bonding in the crystal structure of pyruvylated galactose 6.
Scheme 1
Scheme 1
Synthesis of trisaccharide precursor 14.
See this image and copyright information in PMC

References

    1. Hager F F, Sützl L, Stefanović C, Blaukopf M, Schäffer C. Int J Mol Sci. 2019;20:4929. doi: 10.3390/ijms20194929. - DOI - PMC - PubMed
    1. De Silva R A, Wang Q, Chidley T, Appulage D K, Andreana P R. J Am Chem Soc. 2009;131:9622–9623. doi: 10.1021/ja902607a. - DOI - PubMed
    1. Shi M, Kleski K A, Trabbic K R, Bourgault J-P, Andreana P R. J Am Chem Soc. 2016;138(43):14264–14272. doi: 10.1021/jacs.6b05675. - DOI - PubMed
    1. Nishat S, Andreana P R. Vaccines (Basel, Switz) 2016;4:19. doi: 10.3390/vaccines4020019. - DOI - PMC - PubMed
    1. De Silva R A, Appulage D K, Pietraszkiewicz H, Bobbitt K R, Media J, Shaw J, Valeriote F A, Andreana P R. Cancer Immunol Immunother. 2012;61:581–585. doi: 10.1007/s00262-012-1205-9. - DOI - PMC - PubMed