Synthesis of neisseria meningitidis x capsular polysaccharide fragments

N. meningitidis type X (Men X), first described in the 1960s1, has been found to cause a few cases of invasive disease and in 2006 WHO started to consider Men X as a substantial threat, when an unprecedented incidence of meningitis caused by Men X was observed in Niger and in Western Kenya. The development of carbohydrate-based vaccines has recently emerged as a possible approach with enormous potential benefits for human health. Since capsular polysaccharides (CPSs) are the key virulence factors for encapsulated bacteria, the development of more comprehensive conjugate vaccines including Men X CPS fragments become an urgent issue in the near future. The CPS of N. meningiditis X is a linear homopolymer of (14)-linked 2-acetamido-2-deoxy-alpha-D-glucopyranosyl phosphate residues, with an average chain length of 50 units. The present research project is focused on the synthesis of phosphodiester-linked oligomers of the native Men X CPS. In order to improve the immune response of the synthesized oligomers they will be employed in the synthesis of neo-glycoconjugates by exploiting the amino group of the spacer arm at the reducing end of each fragment.