A robust and universal NMR method for the compositional analysis of polysaccharides

Area of Science:

• Carbohydrate Chemistry
• Analytical Chemistry
• Biochemistry

Background:

• Accurate determination of polysaccharide monomeric composition is crucial for understanding their structure-function relationships.
• Existing methods often suffer from incomplete hydrolysis or significant monosaccharide degradation, limiting their accuracy.

Purpose of the Study:

• To develop a precise and reproducible method for quantifying the monomeric composition of various polysaccharides.
• To optimize hydrolysis conditions to minimize degradation of released monosaccharides.

Main Methods:

• A modified two-step Saeman hydrolysis procedure was employed.
• Quantitative analysis was performed using 600 MHz proton nuclear magnetic resonance ((1)H NMR) spectroscopy.
• Experimental conditions, including hydrolysis duration and sulfuric acid concentration, were optimized.

Main Results:

• The method successfully hydrolyzed resistant polysaccharides completely while minimizing monosaccharide degradation.
• A correction strategy using a standard mixture significantly improved accuracy and reproducibility, with relative deviations down to 1%.
• Hydrolysis duration and sulfuric acid concentration were identified as critical factors for reliable results.

Conclusions:

• The optimized Saeman hydrolysis coupled with (1)H NMR quantification provides a highly accurate and reproducible method for polysaccharide monomeric composition analysis.
• This method is applicable to a wide range of polysaccharides, including resistant types.
• The study highlights the importance of optimizing hydrolysis parameters and implementing degradation correction for reliable analytical outcomes.