Synthesis of Pseudomonas aeruginosa lipopolysaccharide core antigens containing 7-O-carbamoyl-L-glycero-alpha-D-manno-heptopyranosyl residues

The monosaccharide allyl 7-O-carbamoyl-L-glycero-alpha-D-manno-heptopyranos ide, the reducing disaccharide 7-O-carbamoyl-L-glycero-alpha-D-manno-heptop yranosyl-(1 --> 3)-L-glycero-D-manno-heptopyranose and the disaccharides al lyl 7-O-carbamoyl-L-glycero-alpha-D-manno-heptopyranosyl-(1 --> 3)-L-glycer o-beta- and alpha-D-manno-heptopyranoside were prepared in good yields. The 7-O-carbamoyl substituent was regioselectively introduced via NH3-NH4HCO3 treatment of a 6,7-O-carbonate group. Glycosylation steps were carried out using Me3SiOTf or BF3E2O promoted coupling of allyl alcohol with trichloroa cetimidate or fluoride glycosyl donors, respectively. The deprotected allyl glycosides were reacted with cysteamine to afford spacer glycosides which were subsequently linked to bovine serum albumin. The artificial antigens w hich are related to the dephosphorylated heptose region of the lipopolysacc haride core region from Pseudomonas aeruginosa classified into RNA group I may be used for the characterization of monoclonal antibodies directed agai nst inner core epitopes of human-pathogenic Pseudomonas species. (C) 1999 E lsevier Science Ltd. All rights reserved.