Synthesis of the Tetrasaccharide Repeating Unit of the Antigen from Escherichia coli O126 as Its Methyl Glycoside

Efficient activation of thioglycosides with N-(p-methylphenylthio)-ε-caprolactam-TMSOTf

N-(p-Methylphenylthio)-ε-caprolactam (1) in combination with trimethylsilyl trifluoromethanesulfonate (TMSOTf) provides an efficient thiophilic promoter system, capable of activating different thioglycosides. Both 'armed' and 'disarmed' thioglycosyl donors were activated for glycosidic bond formation. Notably, this reagent combination works well in reactivity-based one-pot oligosaccharide assembly strategy.

Chemical synthesis and immunological properties of oligosaccharides derived from the vegetative cell wall of Bacillus anthracis

Bacillus anthracis vaccine candidate : Sera of rabbits exposed to live and irradiated-killed spores of B. anthracis Sterne 34F2 or immunized with B. anthracis polysaccharide conjugated to KLH elicited antibodies that recognize isolated polysaccharide and two synthetic trisaccharides providing a proof-of-concept step in the development of vegetative and spore-specific reagents for detection and targeting of non-protein structures of B. anthracis .

Adhesion Inhibition of F1C-Fimbriated Escherichia coli and Pseudomonas aeruginosa PAK and PAO by Multivalent Carbohydrate Ligands

In order to evaluate their inhibition of bacterial adhesion, the carbohydrate sequences GalNAcbeta1-->4Gal and GalNAcbeta1-->4Galbeta1-->4Glc were synthesized. The disaccharide was conjugated to dendrons based on the 3,5-di-(2-aminoethoxy)-benzoic acid branching unit to yield di- and tetravalent versions of these compounds. A divalent compound was also prepared that had significantly longer spacer arms. Relevant monovalent compounds were prepared for comparison. Their anti-adhesion properties against F1C-fimbriated uropathogenic Escherichia coli were evaluated in an ELISA-type assay by using a recombinant strain and also by using Pseudomonas aeruginosa strains PAO and PAK. Adhesion inhibition was observed in all cases, and multivalency effects of up to one order of magnitude were observed. The combination of spacer and multivalency effects led to a 38-fold increase in the potency of a divalent inhibitor with long spacer arms towards the PAO strain when compared with the free carbohydrate.