Synthesis of the Dideoxyacetamido Disaccharide of Pseudomonas aeruginosa O-Antigen

OBJECTIVE To stereoselectively synthesize a dideoxyacetamido disaccharide of Pseudomonas aeruginosa O-antigen using chemical methods.

METHODS Starting from phenylseleno-D-glucoside, a quinovosamine acceptor building block was efficiently constructed through key steps including the introduction of an anomeric linker, deoxygenation at the C6-hydroxyl, and reductive amination of the C2-azido group. This acceptor was then coupled with a D-fucosamine glycosyl donor via glycosylation to stereoselectively furnish the target α-1,3-linked disaccharide.

RESULTS The target disaccharide was successfully synthesized. The structures of all intermediates and the final product were unambiguously confirmed by nuclear magnetic resonance spectroscopy, high-resolution mass spectrometry, and optical rotation analysis. The product was obtained with high purity.

CONCLUSION The synthetic route for the dideoxyacetamido disaccharide is concise and efficient, affording the target product in high purity, which provides a material basis for subsequent immunological and bioactivity studies on this antigen.