Recovery of natural active molecules using aqueous two-phase systems comprising of ionic liquids/deep eutectic solvents

Due to environmental protection requirements, extraction of bioactive compounds from plant materials using environment-friendly green solvents has always been a research hotspot. And great efforts of scholars have been made in this direction, as well as environment-friendly solvents have been used to develop many innovative extraction techniques. Ionic liquids (ILs) and deep eutectic solvents (DESs) are two kinds of typical designable green solvents, which are potential replacements for traditional volatile organic solvents used for extracting. Under the substances action of inorganic salts or polymers, ILs/DESs can form an aqueous two-phase system (ATPS), which has obvious advantages for separating natural products. This paper discussed the phase separation principle of ILs/DESs-based ATPSs and reviewed the applications in the extraction of natural active molecules in recent years, as well as to promote the development of separation of the active constituents in Chinese materia medica. • The characteristics of ILs/DESs-based aqueous two-phase extraction for the separation of natural active components are discussed. • The review provides useful guide for the design and application of novel ILs/DESs-based aqueous two-phase system. • ATPS extraction can be combined with process intensification techniques (microwave-assisted, ultrasonic assisted, and centrifugal separation) to enhance the extraction and separation process.