Extraction of Natural Products by Direct Formation of Eutectic Systems

A eutectic system forms when two or more substances reorganize into a superlattice that has a lower melting point than each of the individual components. Deep eutectic solvents (DESs) are environmentally friendly solvents often used for the dissolution, extraction, and separation of chemical compounds. Instead of using DESs for extraction, hydrogen bond acceptors (HBAs) or hydrogen bond donors (HBDs) can be used to form a deep eutectic system (DESys) directly with the target compound for one-step dissolution and extraction. The feasibility of direct formation of a DESys for high efficiency extraction was demonstrated with turmeric as the extraction target. The data showed that the target compounds indeed directly interacted with HBAs (and for other compounds, HBDs), which increases process efficiency and reduces the time required for target compounds to compete with another HBD (or HBA) to form hydrogen bonds. In addition, the results showed that the target compounds have different physicochemical properties in DESys and DES, which resulted in different analytical behaviors of the targets. This research may lead to changes in how eutectic systems are used and the development of new applications based on the formation of DESys.