A hydrophobic deep eutectic solvents-based integrated method for efficient and green extraction and recovery of natural products from Rosmarinus officinalis leaves, Ginkgo biloba leaves and Salvia miltiorrhiza roots

Green extraction and separation of natural products is crucial for food industry, and has been widely concerned. Compared with hydrophilic natural products, the green extraction and separation of hydrophobic natural products is more challenging. In this work, a novel method which coupled the ultrasound-assisted extraction with high-speed countercurrent chromatography (HSCCC) separation based on hydrophobic deep eutectic solvent (DES) was proposed for hydrophobic compounds extraction and recovery. By using the developed method, the hydrophobic compounds in Rosmarinus officinalis leaves , Ginkgo biloba leaves and Salvia miltiorrhiza roots have been successfully extracted and recovered. The results indicated that hydrophobic DESs are more effective for extraction hydrophobic compounds than hydrophilic DESs and traditional solvents. And hydrophobic DESs can be used as HSCCC separation solvents to separate and recover hydrophobic compounds effectively. The infinite possibilities of DESs components and their combinations can provide inexhaustible selective space for hydrophobic compounds in the HSCCC separation process.