Ultrasonic-assisted extraction-synergistic deep eutectic solvents for green and efficient incremental extraction of Paris polyphylla saponins

Traditional Chinese medicine Paris polyphylla contains a multitude of bioactive chemicals, primarily sapo-nins, that have been employed in the pharmaceutical sector for anti-cancer and anti-inflammatory func-tions. The low toxicity and exceptional dissolvability of deep eutectic solvents (DESs) make them a promising option in contrast to conventional organic reagents for extraction. This study reports ultrasonic-assisted extraction (UAE) approach was successfully applied for extracting P. polyphylla sapo-nins employing ten DESs based on choline chloride. The chosen DES outperformed water and 80 % etha-nol in terms of extraction performance. The maximum extraction yields of five target saponins in the pilot-scale application were 5.647, 5.984, 0.659, 0.653 and 0.613 mg/g under optimized conditions, which were 1.328-3.229 times higher than those obtained using conventional extraction media after statistical optimization using single-factor experiments and response surface methodology. A scanning electron microscope was used to examine the microstructure of samples before and after extraction. Additionally, five saponins were enriched and recovered with an acceptable recovery yield of 81.33- 90.60 %, and at least four times the regenerating DES could be reused. The ultimate goal of this research was to devise a green, safe, high-efficiency and sustainable strategy to efficiently extract bioactive chem-icals from plant matrices. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study successfully applied the ultrasonic-assisted extraction method to extract Paris polyphylla sapo-nins using deep eutectic solvents (DESs). The chosen DES showed better extraction performance compared to water and ethanol. The extraction yields of target saponins were significantly higher than those obtained from conventional extraction media after optimization. The results suggest the potential application of DESs in efficient extraction of bioactive chemicals from plant matrices.