Title：
Ultrasound-mediated deep eutectic solvent extraction of Gymnema sylvestre polysaccharides: intensified multidimensional optimization and sustainable green metrics assessment
This study developed an efficient and green method for extracting Gymnema sylvestre polysaccharides(GSP) using ultrasound and deep eutectic solvents (DES). Twelve DES systems with different hydrogen bond acceptor/hydrogen bond donor combinations were screened, and choline chloride-citric acid DES was identified as optimal due to its high hydrogen bond acidity and dipolarity, which matched GSP's hydroxyl-rich structure. Single-factor experiments explored the effects of ultrasonic time, temperature, power, DES water content, liquid-to-solid ratio, and choline chloride/citric acid molar ratio on GSP yield. Response Surface Methodology with a 4-factor, 3-level Box-Behnken Design optimized conditions: choline chloride/citric acid molar ratio 1.02:1, DES water content 39.32%, liquid-to-solid ratio 20.21:1, ultrasonic time 39.23 min, temperature 41.35 degrees C, and power 412 W. Under these conditions, GSP yield reached 29.23%, far higher than traditional water extraction (2.29%) and enzyme-assisted extraction (5.83%). GSP was characterized via UV-visible and Fourier transform infrared spectroscopy, confirming typical polysaccharide structures. In vitro assays showed GSP had antioxidant, antibacterial, and anticancer activities. DES maintained stable structure and > 90% extraction efficiency after 5 cycles. An XGBoost model (training set R-2 = 0.998) enabled accurate yield prediction, while six classical green evaluation models quantitatively confirmed the process's environmental friendliness. This work highlights DES as a transformative green solvent for natural product extraction, advancing sustainable GSP production.
Copyright 2002 - 2023 Wuhan Botanical Garden,Chinese Academy Of
Sciences
Email: wbgoffice@wbgcas.cn ICP: 05004779-1
