Full 1H NMR assignment and detailed O-acetylation patterns of capsular polysaccharides from Neisseria meningitidis used in vaccine production

We report essentially complete 1H NMR assignments for the capsular polysaccharides from Neisseria meningitidis serotypes A, C, W-135, and Y. These polysaccharides are components of current polysaccharide vaccines against meningococcal infection and of the polysaccharide-protein conjugate vaccines under development. From these NMR data the pattern of O-acetylation was determined. O-Acetylation of the W-135 polysaccharide is reported for the first time. We also show that, for the Types C and W-135 polysaccharides, a migration of O-acetyl groups occurs during storage in solution, and demonstrate that high field 1H NMR represents a simple and sensitive method to define the O-acetylation pattern of individual batches of these polysaccharides.