A green and highly efficient method of extracting polyphenols from Lilium davidii var. unicolor Salisb using deep eutectic solvents

It is important to find pollution-free, eco-friendly solvents to replace traditional organic solvents. As a new class of medium, deep eutectic solvents (DESs) provide a source of breaking through the green engineering barrier and bring new opportunities for extraction using green chemistry. In this research, the methods of polyphenol extraction from Lilium davidii var. unicolor Salisb with different types of DESs such as choline chloride, betaine, and tetrabutyl ammonium chloride-based DESs were investigated. Compared with traditional extraction solvent systems using methanol, DESs, which are composed of choline chloride and citric acid, have a higher extractive yield. The extraction conditions of polyphenol from Lilium davidii var. unicolor Salisb were studied; moreover, macroporous adsorptive resin was shown to be an efficient way in which to recover polyphenolic compounds. Recovery and reuse of DESs were also analyzed. DESs as "green and designed" solvent can be used to extract polyphenolic compounds from natural products.