Total synthesis of a structurally complex zwitterionic hexasaccharide repeating unit of polysaccharide B from Bacteroides fragilis via one-pot glycosylation.

ABSTRACT: Zwitterionic polysaccharides (ZPSs) present on the surface of a common gut commensal Bacteroides fragilis are endowed with unique immunological properties as they can directly bind to T-cells in the absence of protein conjugation. ZPSs are therefore considered to be potential antigens for the development of totally carbohydrate-based vaccines. Herein, we disclose the first total synthesis of a highly branched phosphorylated zwitterionic capsular polysaccharide repeating unit of Bacteroides fragilis. The hexasaccharide repeating unit bearing six different monosaccharides comprises three 1,2-cis-glycosidic linkages, a challenging 1,2-trans linkage in D-QuipNAc-β-(1→4)-D-Gal motif, and a 2-aminoethyl phosphonate appendage. The synthesis of target ZPS was accomplished utilizing an expeditious,

SUBMITTER: Puri K 

PROVIDER: S-EPMC11405768 | biostudies-literature | 2024 Sep

REPOSITORIES: biostudies-literature