NMR analysis of compositional heterogeneity in polysaccharides

Authors: Cheng, Huai

Submitted to: Pure and Applied Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/24/2016
Publication Date: 7/1/2017
Citation: Cheng, H.N. 2017. NMR analysis of compositional heterogeneity in polysaccharides. Pure and Applied Chemistry. 89(7):877-883.

Interpretive Summary: Polysaccharides are important raw materials for food and industrial applications. Because they are natural materials extracted from plants, they are often heterogeneous in composition. Thus, a conventional analysis of a copolysaccharide can only give an average value for composition. It is shown in this work that NMR spectroscopy can enable the extent of compositional heterogeneity to be estimated in some polysaccharides. Two methodologies can be used, depending on the nature of the heterogeneity. These methodologies will allow us to use NMR as a quality control method to detect the presence or the absence of heterogeneity in these polysaccharides.

Technical Abstract: Many copolysaccharides are compositionally heterogeneous, and the composition determined by the usual analytical or spectroscopic methods provides only an average value. For some polysaccharides, the NMR data contain copolymer sequence information, such as diad, triad, and tetrad sequence intensities. In such cases, it is possible to estimate the extent of compositional heterogeneity through NMR. Two general types of methodologies can be used: perturbed Markovian and discrete component approaches. The theoretical bases for these approaches are reviewed in this work, and three examples are shown of the application of these NMR methodologies to copolysaccharides.