CO2-triggered switchable hydrophilicity solvent as a recyclable extractant for ultrasonic-assisted extraction of Polygonatum sibiricum polysaccharides

In this study, CO2-triggered switchable hydrophilicity solvents (SHSs) based on different amines and water were employed in the ultrasonic-assisted extraction of Polygonatum sibiricum polysaccharides (PSPs). When CO2 was pumped into the amine, the solution became hydrophilic and could be used as an extractant for PSPs extraction. When CO2 was removed, the solution switched hydrophobicity, with the extractants being separated from the extract and further recycled and reused. The factors affecting the solid-liquid extraction of PSPs were studied. The maximum extraction yield of 399.2 mg/g was obtained at a solid-liquid ratio of 1:20, extraction time of 60 min, extraction temperature of 50 degrees C, and ultrasonic power of 500 W. SHSs could be recovered and reused with 88.4% recovery after the fifth cycle. The molecular weights and monosaccharide compositions of PSPs were also determined. This study provides a new strategy for sustainable extraction of plant polysaccharides and other bioactive ingredients.

Automated summary

This study employed CO2-triggered switchable hydrophilicity solvents (SHSs) in ultrasonic-assisted extraction to extract Polygonatum sibiricum polysaccharides (PSPs). The solvents became hydrophilic in the presence of CO2, allowing for extraction of PSPs. Upon removal of CO2, the solvents switched to hydrophobicity, separating the extractants from the extract for recycling. Factors affecting PSPs extraction were investigated, and optimal extraction conditions were determined. The SHSs exhibited high recovery rates after multiple cycles and the characteristics of the extracted PSPs were analyzed. This study presents a novel strategy for sustainable extraction of plant polysaccharides and other bioactive ingredients.