Determination of C-Polysaccharide Content in Streptococcus Pneumoniae Capsular Polysaccharides by Quantitative Proton Magnetic Resonance Spectroscopy
A quantitative nuclear magnetic resonance(qNMR)method to analyze the content of residual C-polysaccharide(C-Ps)in the Streptococcus pneumoniae capsular polysaccharide was developed.The characteristic peak for C-Ps was confirmed at δH 3.24 by 2D 1H-15N heteronuclear multiple bond correlation(HMBC).By using pneumococcal serotypes 6A,6B and 10A capsular polysaccharids as model samples and dimethyl sulfone as internal standard,the proton qNMR(1H qNMR)absolute quantitation method was established and validated.The linear detection range for C-Ps was 2.5-198 μg/mL(R2>0.999),the limit of quantification was 2.5 μg/mL,and the spiked recoveries were 102%‒109%.The relative standard deviation(RSD)of repeatability and the RSD of 5 days stability of this method were lower than 3%and 1%,respectively.The established 1H qNMR method could be successfully used to determine the absolute C-Ps contents of Streptococcus pneumoniae capsular polysaccharides.This method showed many advantages such as simple operation,good repeatability and robustness,and could be easily adopted for the quality control of Streptococcus pneumoniae capsular polysaccharides during the research and development stages.
Quantitative proton nuclear magnetic resonanceStreptococcus pneumoniae capsular polysaccharideC-polysaccharidePhosphocholineQuality control