title: Synthesis of an Aminooxy Derivative of the Tetrasaccharide Repeating Unit of Streptococcus dysgalactiae 2023 Polysaccharide for a PS A1 Conjugate Vaccine.
abstract: A highly efficient and stereocontrolled synthesis of an aminooxy derivative of the tetrasaccharide repeating unit of a rhamnose-rich polysaccharide isolated from the cell envelop of bovine mastitis Streptococcus dysgalactiae 2023 is reported for the first time. The synthesis was accomplished utilizing a stereoselective and convergent [2 + 2] glycosylation strategy inclusive of a disaccharide Schmidt donor and an inclusive rhamnose disaccharide acceptor. The synthetic aminooxy tetrasaccharide was conjugated to T-cell stimulating immunogen PS A1 from Bacteroides fragilis ATCC 25285/NCTC 9343 via a physiologically stable oxime linkage to furnish the first semisynthetic bacterial-based immunogen construct targeting S. dysgalactiae 2023. The synthetic tetrasaccharide was assembled in 19 steps with a ∼5.0% overall yield.
authors.affiliation: Department of Chemistry and Biochemistry and School of Green Chemistry and Engineering, University of Toledo , 2801 W. Bancroft Street, Toledo, Ohio 43606, United States.
authors.forename: Samir
authors.initials: S
authors.lastname: Ghosh
authors.affiliation: Department of Chemistry and Biochemistry and School of Green Chemistry and Engineering, University of Toledo , 2801 W. Bancroft Street, Toledo, Ohio 43606, United States.
authors.forename: Sharmeen
authors.initials: S
authors.lastname: Nishat
authors.affiliation: Department of Chemistry and Biochemistry and School of Green Chemistry and Engineering, University of Toledo , 2801 W. Bancroft Street, Toledo, Ohio 43606, United States.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Andreana
mesh_terms: D000818:Animals; D001441:Bacteroides fragilis / Q000276:immunology; D002240:Carbohydrate Sequence; D002417:Cattle; D005260:Female; D006031:Glycosylation; D008414:Mastitis, Bovine / Q000276:immunology / Q000382:microbiology; D010091:Oximes / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry* / Q000276:immunology*; D013237:Stereoisomerism; D013291:Streptococcus / Q000737:chemistry* / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D018074:Vaccines, Conjugate / Q000737:chemistry* / Q000276:immunology*
chemical_list: D010091:Oximes; D011134:Polysaccharides; D018074:Vaccines, Conjugate