Switching from deep eutectic solvents to deep eutectic systems for natural product extraction

This article presents a comprehensive overview of recent advancements in natural product extraction, focusing on the evolution from deep eutectic solvents (DESs) to deep eutectic systems (DESys) for extraction. DESs, known for their environmentally friendly properties, have become crucial in extracting various natural products from plants, including micromolecules, lignin, and polysaccharides. Research into the extraction mechanism reveals that target compounds typically form hydrogen bonds with DESs, effectively becoming part of the solvent system. This insight has led to the development of the DESys extraction method, where hydrogen bond acceptors (HBAs) and hydrogen bond donors (HBDs) are directly mixed with the sample to form a DESys containing the target compounds. The shift from DES-based extraction to DESys-based extraction introduces innovative approaches where target compounds are integral to the solvent system, allowing for one-step dissolution and extraction. This methodology eliminates the need for pre-prepared DESs, simplifying processes and enhancing extraction efficiency. Additionally, strategies for DESs recycling and reuse contribute to sustainability efforts, offering cost-effective and environmentally friendly extraction solutions. The expanding applications of DES-based and DESys-based natural product extraction in cosmetics, food, industry, and environmental fields highlight their promising development potential. By delineating the transition from DES-based to DESys-based extraction of natural products, this review offers valuable insights for advancing the practice of green chemical engineering.