title: Application of ionic liquid-based microwave-assisted extraction of flavonoids from Scutellaria baicalensis Georgi.
abstract: In the present work, a rapid ionic liquid-based microwave-assisted extraction (ILMAE) method was successfully applied to simultaneous extraction of baicalin, wogonoside, baicalein and wogonin from Scutellaria baicalensis Georgi. A series of 1-alkyl-3-methylirnidazolium ionic liquids with different anions and cations were assessed for extraction efficiency, and 1-octyl-3-methylimidazolium bromide was selected as the optimal solvent. In addition, the parameters of ILMAE procedure for the four flavonoids were optimized, and the optimal ILMAE method was validated in the linearity, stability, precision and recovery. Meanwhile, the microstructures of S. baicalensis powders were observed before and after extraction with the help of a scanning electron microscope (SEM) in order to explore the extraction mechanism, and the activity of the crude enzyme solution from S. baicalensis was determined through the hydrolysis of baicalin. Finally, the extraction yields and extraction time of WaterHRE, WaterMAE, ILHRE and Chp were 5.18% (30min), 8.77% (90s), 16.94% (30min) and 18.58% (3h), respectively. The results indicated that compared with the conventional extraction approaches, ILMAE possessed great advantages in extracting flavonoids, such as the highest extraction yield (22.28%), the shortest extraction time (90s), etc.
authors.affiliation: The Institute of Molecule Science of Shanxi University, Taiyuan 030006, PR China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: The Institute of Molecule Science of Shanxi University, Taiyuan 030006, PR China.
authors.forename: San-Hu
authors.initials: SH
authors.lastname: Zhao
authors.affiliation: The Institute of Molecule Science of Shanxi University, Taiyuan 030006, PR China.
authors.forename: Jue
authors.initials: J
authors.lastname: Chen
authors.affiliation: The Institute of Molecule Science of Shanxi University, Taiyuan 030006, PR China. Electronic address: lwzhang@sxu.edu.cn.
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Zhang
mesh_terms: D005419:Flavonoids / Q000302:isolation & purification*; D052578:Ionic Liquids / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008872:Microwaves; D031364:Scutellaria baicalensis / Q000737:chemistry*
chemical_list: D005419:Flavonoids; D052578:Ionic Liquids
keywords: Flavonoids; Ionic liquids; Microwave-assisted extraction (MAE); Scanning electron microscopy (SEM); Scutellaria baicalensis Georgi