Chemical synthesis of fragments of streptococcal cell wall polysaccharides

Abstract

This thesis describes the design and synthesis of fragments of various cell wall carbohydrates of the Streptococcus species, including the branched Group B-specific antigen (GBC) of Group B Streptococcus, glycerol phosphate (GroP) modified group A carbohydrate (GAC), and the O-acetylated type 1 capsular polysaccharide of Streptococcus pneumonia (Sp1). All the synthesized fragments were equipped with a spacer at the reducing end for further conjugation with proteins or active small molecules to explore the mechanisms of carbohydrate-based vaccines in immune responses and to develop novel vaccines. To investigate the structure-activity relationship, several fragments of each polysaccharide were assembled varying in length.