Deep eutectic solvents as green media for extraction of flavonoid glycosides and aglycones from Platycladi Cacumen

Deep eutectic solvents (DESs) are emerging as alternatives to conventional ionic liquids and organic solvents due to their unique advantages. In the present study, the tuneability of DESs as tailor-made solvents to efficiently extract polar and non-polar bioactive compounds from Platycladi Cacumen was detailedly investigated. Totally 12 types of choline chloride-, betaine-, and l-proline-based DESs were synthesized for initial screening, and extraction conditions was optimized by single-factor experiment. Experiments with different DESs and principal components analysis demonstrated that the extractability of both flavonoid glycosides and aglycones was greater with certain designed DESs than conventional solvents. In addition, the water content in DESs led to significantly different extraction yields of flavonoid compounds. The target compounds were recovered from DESs by macroporous resin LX-38 with a satisfactory yield between 77.44% and 98.92%. The knowledge acquired in this study could contribute to further DES application in extraction of bioactive compounds from natural sources.