Nuclear magnetic resonance assessment of controlled hydrolysis of the capsular polysaccharides of Streptococcus pneumoniae serotypes 19A and 19F

Abstract

ABSTRACTSeveral glycoconjugate-based vaccines are inserted nowadays in infant vaccination schedules of most countries. In an initial stage, polysaccharides are modified under controlled conditions. The assessment of polysaccharide regions available for conjugation process after the hydrolysis is crucial to predict the conjugation results for achieving the final active pharmaceutical ingredient. Two hydrolyzed capsular polysaccharides were analyzed by a heteronuclear single-quantum correlation experiment. It was adjusted for assessing 3JP-H to check the position of phosphate mono-ester residue after the hydrolysis process. All evaluated polysaccharides have been shown to remain with the anomeric position available for subsequent conjugation. The adjusted spectroscopic experiment was shown to be effective to study the hydrolysis of phosphate di-ester linked to capsular polysaccharides.