Deep eutectic solvents boosting solubilization and Se-functionalization of heteropolysaccharide: Multiple hydrogen...

Area of Science:

• Green Chemistry
• Biopolymer Science
• Materials Science

Background:

• Natural heteropolysaccharides present challenges in solubilization and functionalization due to complex structures.
• Conventional functionalization methods often lack efficiency and control over derivative properties.

Purpose of the Study:

• To investigate the feasibility of deep eutectic solvents (DESs) for efficient solubilization and Se-functionalization of Artemisia sphaerocephala (PAS) heteropolysaccharide.
• To explore the role of DES constituents in controlling the functionalization efficiency and derivative structure.
• To compare DES-mediated Se-functionalization with conventional methods.

Main Methods:

• Experimental validation of DES performance.
• Density functional theory (DFT) calculations to understand solvent-polysaccharide interactions.
• Choline chloride-based DES/DMSO binary mixed solvents were employed.
• Se-functionalization of PAS using DES/DMSO.

Main Results:

• Choline chloride-based DES/DMSO demonstrated superior solubilization of PAS by optimizing hydrogen bond disruption and reconstruction.
• DES/DMSO significantly enhanced Se-functionalization efficiency due to exposed and activated polysaccharide hydroxyl groups.
• The resulting Se-functionalized derivative showed reduced molecular mass and a rigid solution conformation, influenced by co-solvent effects and an acidic environment.

Conclusions:

• DESs offer a highly feasible and efficient approach for heteropolysaccharide solubilization and functionalization.
• Modulating DES composition provides a framework for tailored polysaccharide functionalization, controlling conversion efficiency and derivative structure.
• This study advances green chemistry applications in biopolymer modification.