A Green Method of Extracting and Recovering Flavonoids from Acanthopanax senticosus Using Deep Eutectic Solvents

In recent years, green extraction of bioactive compounds from herbal medicines has generated widespread interest. Deep eutectic solvents (DES) have widely replaced traditional organic solvents in the extraction process. In this study, the efficiencies of eight DESs in extracting flavonoids from Acanthopanax senticosus (AS) were compared. Response surface methodology (RSM) was employed to optimize the independent variable including ultrasonic power, water content, solid-liquid ratio, extraction temperature, and extraction time. DES composed of glycerol and levulinic acid (1:1) was chosen as the most suitable extraction medium. Optimal conditions were ultrasonic power of 500 W, water content of 28%, solid-liquid ratio of 1:18 g center dot mL(-1), extraction temperature of 55 degrees C, and extraction time of 73 min. The extraction yield of total flavonoids reached 23.928 +/- 0.071 mg center dot g(-1), which was 40.7% higher compared with ultrasonic-assisted ethanol extraction. Macroporous resin (D-101, HPD-600, S-8 and AB-8) was used to recover flavonoids from extracts. The AB-8 resin showed higher adsorption/desorption performance, with a recovery rate of total flavonoids of up to 71.56 +/- 0.256%. In addition, DES solvent could efficiently be reused twice. In summary, ultrasonic-assisted DES combined with the macroporous resin enrichment method is exceptionally effective in recovering flavonoids from AS, and provides a promising environmentally friendly and recyclable strategy for flavonoid extraction from natural plant sources.

Automated summary

In this study, the efficiency of different deep eutectic solvents (DES) in extracting flavonoids from Acanthopanax senticosus (AS) was compared. The optimal conditions for extraction were determined using response surface methodology. The results showed that DES composed of glycerol and levulinic acid (1:1) was the most suitable extraction medium, achieving a higher extraction yield compared to traditional ethanol extraction. Additionally, the use of macroporous resin further enhanced the recovery of flavonoids from the extracts.