Extraction of aloe polysaccharides by recoverable aqueous biphasic system composed of thermo-sensitive magnetic ionic liquid and pH-sensitive copolymer

In this work, thermo-sensitive magnetic ionic liquids were applied to construct aqueous biphasic systems with pH-sensitive copolymers. These triple-responsive aqueous biphasic systems have been developed for the purification of aloe polysaccharides from crude extract of aloe pulp. These systems are responsive to external magnetic field and can accelerate phase separation applying only a magnet. Thermo-sensitive magnetic ionic liquid and pH-sensitive copolymer as phase-forming reagents can be effortlessly recovered through heating and pH adjustment without any use of organic solvents. The developed system presents several benefits, including expeditious extraction, magnet-assisted phase separation, efficient recovery induced by temperature and pH changes, especially without utilization of any organic solvent throughout the entire extraction and recovery procedures. Comprehensive studies on phase behaviors were carried out, providing valuable insights for extraction applications. The process of extraction, purification and recovery of aloe polysaccharides were thoroughly examined and optimized. Under optimal conditions, a near-total extraction of aloe polysaccharides was observed in the copolymer-rich phase, while the majority of the primary impurity, protein, was partitioned into the magnetic ionic liquid phase. Subsequent analyses of monosaccharide constituents confirmed high purity of the aloe polysaccharides product, with no impurities found. The recycled magnetic ionic liquid and copolymer have been demonstrated to possess recyclability for a minimum of seven cycles, exhibiting steadily good performance. This simple and green aqueous biphasic system exhibits considerable potential for extraction and purification of aloe polysaccharides, as well as other natural products.