Synthesis of Oligosaccharides Resembling the Streptococcus suis Serotype 18 Capsular Polysaccharide as a Basis for Glycoconjugate Vaccine Development

Abstract

Here we report the first total synthesis of several oligosaccharides resembling the capsular polysaccharide of swine pathogen S. suis serotype 18 repeating unit [→3)- d -GalNAc(α1-3)[ d -Glc(β1-2)]- d -GalA4OAc(β1-3)- d -GalNAc(α1-3)- d -BacNAc4NAc(α1→] n . Access to the pentasaccharide repeating unit antigen proved to be very challenging due to the poor reactivity in the context of the trisaccharide. The challenge was overcome by the creation of a galacturonic acid in a late stage of the synthesis.

Synthesis of oligosaccharides to identify an immunologically active epitope against Candida auris infection

“…Levulinoylation of the C2–OH in 10 using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC·HCl) and DMAP produced 11 in 86% yield. 15,16 Hydrolysis of thioglycoside 11 using N -bromosuccinimide (NBS) and subsequent treatment of hemiacetal 16 11 with diphenyl phosphite provided H -phosphonate 13 . 17…”

“…Levulinoylation of the C2-OH in 10 using 1-ethyl-3-(3dimethylaminopropyl) carbodiimide hydrochloride (EDC$HCl) and DMAP produced 11 in 86% yield. 15,16 Hydrolysis of thioglycoside 11 using N-bromosuccinimide (NBS) and subsequent treatment of hemiacetal 16 11 with diphenyl phosphite provided H-phosphonate 13. 17 Union of D-thiomannoside 18 15 and aminopentyl linker 19 14 promoted by NIS/TfOH afforded desired a-linked glycoside 16 in 85% yield (Scheme 2).…”

Semi‐Synthetic Glycoconjugate Vaccine Lead Against Acinetobacter baumannii 17978

“…Synthesis of protected monosaccharides 3 – 14 relied on slightly modified literature precedence (Supporting Information, Schemes S1 and S2), [17] while a synthesis of diamino‐D‐glucuronate 12 from commercially available D‐glucosamine was developed. The installation of azide group in 12 relied on double inversion at C3 via Lattrell‐Dax inversion[ 17g , 17h ] (Supporting Information, Scheme S3).…”

Semi‐Synthetic Glycoconjugate Vaccine Lead Against Acinetobacter baumannii 17978

“…Synthesis of protected monosaccharides 3 – 14 relied on slightly modified literature precedence (Supporting Information, Schemes S1 and S2), [17] while a synthesis of diamino‐D‐glucuronate 12 from commercially available D‐glucosamine was developed. The installation of azide group in 12 relied on double inversion at C3 via Lattrell‐Dax inversion [17g,h] (Supporting Information, Scheme S3).…”