ABSTRACT
Chemical synthesis has played a role in the modern field of lipopolysaccharide (LPS) research, particularly in relation to the structure and function of lipid A, which is the active entity of LPS. The success of the first chemical synthesis of lipid A made an epoch-making contribution to the field: a synthetic specimen prepared according to the structure proposed for lipid A of Escherichia coli F515 showed identical full endotoxic activity observed with the corresponding bacterial preparation. This compound shares the same hydrophilic backbone structure of bisphosphorylated glucosamine ß(1–6)disaccharide with mature lipid A but contains two fewer fatty acyl groups than the latter. Such a line of research may lead to the discovery of new, possibly artificial compounds with clinical values. In addition to the cyclic ester protection of the phosphate, the protection strategy for the glucosamine residues was also changed in the following several points. The 6-hydroxy group in the glycosyl donor.
