Application of Choline Chloride as Natural Deep Eutectic Solvents for the Green Extraction of Phenolic Compounds from Rheum Ribes Leaves

Abstract

Deep eutectic solvents are applied as a new type of sustainable solvents.The new generation of green solvents are considerable utilize to extraction of bioactive compounds due to their physicochemical properties and structure. In this study, the extraction process of phenolic compounds from rhubarb roots using of ultrasound-assisted extraction (UAE) method was investigated.Totally 8 different types of choline chloride- and L-proline-based deep eutectic solvents containing various H-bond donors/acceptors were synthesized.The extraction conditions for phenolic acids such as effect of different DESs,extraction temperature,water content in nades,ratio of solid to liquid and extraction time were studied.The optimal parameters were found to be extraction time of 30 min, temperature of 313.15 K, DES 30 wt % water and solid/liquid ratio of 1:20 led to significantly effect on the extraction of phenolic contents from plant material. The quantification and characterization of two biactive flavonoids in the extracts was analyzed via ultra-high pressure liquid chromatography (UPLC) with photodiode dedection.Compared with conventional extraction system, deep eutectic solvents (DESs) showed high extraction efficiency for both polar and less polar compounds. This study reveals,the developed DESs have significant as alternative new green dissolving agents in the extraction of phenolic compounds from plant resource due to their high solubilization ability and low toxicity.