The Rise of Green Solvents: Application and Efficiency of Deep Eutectic Solvents in the Extraction of Flavonoids

Deep eutectic solvents (DESs) provide a sustainable and effective way to extract flavonoids from herbal medicines, which are known for their notable antioxidant effects. Traditional extraction approaches are often costly and utilize harmful solvents. This review summarizes the fundamental concepts, preparation methods, and key factors that affect the safe and effective use of DESs for extracting flavonoids. The adaptability of DESs enables their integration with other green extraction technologies, such as ultrasound- and microwave-assisted extractions, thereby enhancing their extraction efficiency. The extraction mechanism of flavonoids by DESs mainly includes the hydrogen bonding interactions between the DESs and flavonoids. This adaptability also highlights the potential of DESs for the eco-friendly extraction of flavonoids. Current research shows that DESs may significantly contribute to the sustainable sourcing of flavonoids, representing a major advancement in the extraction and purification of flavonoids. Several future research directions about the extraction of flavonoids using DESs were also proposed, such as scaling up industrial processes, developing sustainable formulations of DESs, and integrating with other extraction techniques. The review points out those DESs are a practical and environmentally friendly choice for natural extraction methods, greatly supporting sustainable practices in flavonoids extraction.