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.
Peng-Bo Duan,Ping-Ting Xiao,Xing Yang,Jin-Hua Hao,Kai Li,E-Hu Liu
In this work, the hypoglycemic components in Platycladi Cacumen, an essential traditional Chinese medicine, were evaluated by combining phytochemical investigation, spectrum-effect relationship analysis, and chemometric methods. The phytochemical studies on Platycladi Cacumen extract lead to the isolation of 21 potential bioactive compounds. The chromatographic fingerprints of Platycladi Cacumen samples were established by high-performance liquid chromatography. The hypoglycemic effects of Platycladi Cacumen samples were further evaluated by inhibition of α-glucosidase and detected by the high-performance liquid chromatography method. The spectrum-effect relationship study by bivariate correlations analysis and orthogonal partial least squares regression revealed that myricitrin (P9), quercitrin (P13), afzelin (P18), and amentoflavone (P24) were more relevant to the α-glucosidase inhibitory activity. The results of α-glucosidase inhibitory activity of 21 isolated compounds and molecular docking studies also indicated these flavonoids had potent α-glucosidase inhibitory activity. Collectively, the present study established the spectrum-effect relationship mode of Platycladi Cacumen and discovered the major hypoglycemic components, which provides a feasible method for screening bioactive components.