High effective extraction of selected anthraquinones from Polygonum multiflorum using ionic liquids with ultrasonic assistance

In recent years, the toxicity of Polygonum multiflorum has been attributed to the anthraquinones. Therefore, the selective removal of anthraquinones will effectively improve the safety of Polygonum multiflorum. An ionic liquid-based extraction was firstly proposed to selectively extract anthraquinones from herbal powders with ultrasonic assistance. The relationship between selective extraction effect and important extraction conditions was investigated. Furthermore, the mechanism of the selective extraction was explored with the extraction kinetics and computation method. In addition, the recovery of ionic liquids was also investigated. Finally, high extraction efficiency (97.2%) and good selectivity (7.32) for anthraquinones from Polygonum multiflorum were achieved, and the ionic liquid was recovered with satisfactory recovery rate. It could provide a promising alternative method to isolate anthraquinones from other natural products. (C) 2020 Published by Elsevier B.V.