Strategies for green extraction of Dioscin from Dioscorea nipponica Makino by ultrasound-assisted switchable natural deep eutectic solvents

Traditional maceration extraction methods for dioscin typically involve substantial consumption of organic solvents and long extraction times. The present study aimed to develop a green and sustainable extraction procedure for the extraction of Dioscin from Dioscorea nipponica Makino (DNM). A series of switchable natural deep eutectic solvent (SNADES) based on medium chain fatty acids were prepared to achieve high extraction efficiency of Dioscin from DNM. As a result, hexanoic acid and heptanoic acid were selected as the optimal solvents. The optimal extraction conditions were as follows: a molar ratio of 1:1, a liquid-solid ratio of 50 mL·g −1 , an ultrasonic duration of 50 min, and a polarity switch phosphoric acid dosage of 800 μL without additional salt. The SNADES-UALLME method established in this study minimizes the use of organic reagents and provides a new insight for development of green extraction methods for active ingredients from traditional Chinese medicine.