Acidic dimethyl sulfoxide: A solvent system for the fast dissolution of pectin derivatives suitable for subsequent modification

Abstract

This study investigates the use of dimethyl sulfoxide (DMSO) as a solvent for the dissolution and subsequent chemical modification of various pectin derivatives. DMSO was found to effectively dissolve low-methoxy pectin, high-methoxy pectin, polygalacturonic acid hydrazide, pectin amide, and polygalacturonic hydroxamic acid when the negative charges on the polysaccharide backbone were neutralized with organic acids. The dissolution process was further enhanced by increasing the temperature, although higher temperatures also promoted chain cleavage. The dissolved pectin derivatives were successfully modified through transesterification and Schiff base formation, demonstrating the potential of acidic DMSO as a non-toxic and cost-effective solvent system for homogeneous pectin chemistry. The study opens new possibilities for the functionalization of pectin in various industrial and biomedical applications.