Synthesis of 2-deoxy-4-O-alpha- and -beta-D-mannopyranosyl-L-erythro-pentonic acids

The tetrasaccharide L-alpha-D-heptose1-->2-L-alpha-D-heptose1--> 3-L-alpha-D-heptose1-->(3-deoxy-D-manno-octulosonic acid) and phosphate in lipid A define the conserved epitope in Haemophilus lipopolysaccharides recognized by a monoclonal antibody

A murine monoclonal antibody, MAHI 3 (immunoglobulin G2b), that is broadly reactive with Haemophilus influenzae lipopolysaccharides (LPSs) but nonreactive with all enterobacterial LPSs tested was generated by fusing mouse myeloma cells with spleen cells of BALB/c mice immunized with azide-killed H. influenzae RM.7004. MAHI 3 bound to all H. influenzae, all other human Haemophilus spp., all Bordetella pertussis and Bordetella parapertussis, and all Aeromonas spp. tested but not to any Neisseria or Moraxella catarrhalis strains, as determined by enzyme immunoassay, colony dot immunoblotting, and immunoblotting. In an inhibition enzyme immunoassay, MAHI 3 reacted with all 45 H. influenzae LPSs tested but not with the LPS from the rough mutant I69 Rd-/b+, which has only 3-deoxy-D-manno-octulosonic acid (P) [Kdo(P)] and lipid A. The antibody was not inhibited by H. influenzae lipid A or lipid-free polysaccharide isolated after mild acid hydrolysis. Only native LPSs show positive inhibitory activity, indicating that part of lipid A is involved in the binding of MAHI 3. From the results, it is indicated that the structural element recognized by MAHI 3 is Hep alpha 1-->2Hep alpha 1-->3Hep alpha 1-->Kdo together with part of lipid A, including the phosphate.

Structure of a hexasaccharide proximal to the hydrophobic region of lipopolysaccharides present in Bordetella pertussis endotoxin preparations

A branched-chain hexasaccharide containing 3-deoxy-D-manno-oct-2-ulosonic acid was released by detergent-promoted hydrolysis from Bordetella pertussis endotoxin preparations that were first dephosphorylated with aqueous HF and then treated with nitrous acid. Its structure (2) [Formula: See text] was determined by chemical and physical methods. This hexasaccharide is present in all four lipopolysaccharides that make up the B. pertussis strain 1414 (phase 1) endotoxin preparations analysed, and is situated near to the hydrophobic domains. An analogous structure reported previously (ref 7) is erroneous and should be disregarded.

Synthesis of allyl 6-O-(3-deoxy-alpha- and -beta-D-manno-oct-2- ulopyranosylonic acid)-(1----6)-2-deoxy-2-[(3R)-3-hydroxytetradecanamido]- beta-D-glucopyranoside 4-phosphate and of the copolymer of the alpha anomer with acrylamide

The title disaccharides were synthesized by mercuric cyanide-catalyzed condensation of methyl (4,5,7,8-tetra-O-acetyl-3-deoxy-alpha-D-manno-oct-2-ulopyranosyl bromide)onate and allyl 2-[(3R)-3-acetoxy-tetradecanamido]-3-O-benzyl-2-deoxy-beta-D- glucopyranoside, followed by phosphorylation of the alcoholic function of the amino sugar. The phosphorylated anomers were separated by chromatography and deprotected by conventional methods. Polymeric material was obtained by copolymerisation, catalyzed by peroxosulphate and N,N,N',N'-tetramethylethylenediamine, of the alpha anomer with acrylamide; it contained ca. one disaccharide unit for 18 acrylamide residues.