Aqueous biphasic systems based on dual deep eutectic solvents for simultaneous extraction and targeted partitioning...

A green extraction method using dual deep eutectic solvents (DESs) in aqueous biphasic systems (ABSs) was developed for Cinnamomum cassia (C. cassia). 16 DES-based ABSs were constructed utilizing IL-based DESs (I) as the chaotropic agent and DESs (II) as the kosmotropic agent. An optimal system (DES I:DES II:H₂O = 3:3:4) efficiently extracted polysaccharides, phenols, flavonoids, and organic acids. Notably, polysaccharides were exclusively partitioned into the bottom phase, while other compounds were enriched in the top phase for the system composed of DES I (tetrabutyl-ammonium trifluoroacetate:glycerol) and DES II (glucose:fructose). Based molecular simulation, hydrogen bonding, van der Waals interactions, and electrostatic interactions may mainly govern the distribution of bioactive compounds. Correlation analysis identified viscosity as the key factor influencing efficiency. The extracted compounds retained potent antioxidant and antibacterial activities. This study provides a sustainable and effective strategy for the integrated extraction and separation of multiple bioactive compounds from C. cassia.