ATR-FTIR spectra of polysaccharide isolated from Euphorbia caducifolia and its chemical modifications: A study of Principal component analysis

Abstract

Polysaccharides are the carbohydrates composed of same or different types of saccharides in an organized manner with glycosidic bonds. These are useful for various industrial applications mainly in food and pharmaceutical companies. Modifications of the polysaccharides change its structure and lead to the physical as well as functional differences. Mostly, chemical methods are used to modify its structure to study the structure-activity relationship in interest towards its physical properties like solubility and biological activities among various types of molecular modifications. In this study, a polysaccharide isolated from stems of Euphorbia caducifolia and modified its structure chemically by substituting different groups by sulfonation, carboxymethylation, acetylation and phosphorylation with various degree of substitutions. Molecular modifications of the polysaccharides showed the impact on water solubility as a physiochemical property. Thus, ATR-FTIR spectroscopy was employed along with a chemometric analysis, i.e., Principal components analysis (PCA) to understand and identify the chemical moieties differed from the unmodified polysaccharide. From PCA analysis, PC1 and PC2 components suffice to differentiate the modified polysaccharides with its native form.