Ji Shuai, Wang Yujie, Su Zhenyu, He Dandan, Du Yan, Guo Mengzhe, Yang Dongzhi, Tang Daoquan
Department of Pharmaceutical Analysis, School of Pharmacy, Xuzhou Medical University 209 Tongshan Road Xuzhou 221004 China
Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University 209 Tongshan Road Xuzhou 221004 China
RSC Adv. 2018 Apr 16;8(25):13989-13996. doi: 10.1039/c8ra01056k. eCollection 2018 Apr 11.
Flavonoid glycosides and triterpenoid saponins are the main chemical constituents of licorice. In this study, an ionic liquids-ultrasound based extraction (IL-UAE) method was established to simultaneously extract liquiritin (LQ), liquiritin apioside (LA), isoliquiritin (ILQ), isoliquiritin apioside (ILA) and glycyrrhizic acid (GA) from licorice. A series of 1-alkyl-3-methylimidazolium ILs with different anions and alkyl chain lengths of cations were investigated and compared, and 1-butyl-3-methylimidazolium acetate ([CMIM]Ac) was finally selected as the extractant. The extraction parameters of the IL-UAE procedure were optimized, and the established method was validated in linearity, stability, precision, repeatability and recovery. The IL-UAE approach exhibited much higher extraction efficiency comparing with conventional UAE, and needed shorter extraction time and smaller solvent to solid ratio comparing with the pharmacopoeia method. In addition, the microstructures of licorice powders were observed before and after extraction with help of a scanning electron microscope (SEM) in order to explore the extraction mechanism. The results suggested that ILs as green solvents were effective for extraction of flavonoid glycosides and triterpenoid saponins from licorice.
黄酮苷和三萜皂苷是甘草的主要化学成分。本研究建立了一种基于离子液体-超声的萃取（IL-UAE）方法，用于同时从甘草中提取甘草苷（LQ）、甘草苷芹糖基苷（LA）、异甘草苷（ILQ）、异甘草苷芹糖基苷（ILA）和甘草酸（GA）。研究并比较了一系列具有不同阴离子和阳离子烷基链长度的1-烷基-3-甲基咪唑鎓离子液体，最终选择1-丁基-3-甲基咪唑鎓乙酸盐（[CMIM]Ac）作为萃取剂。对IL-UAE方法的萃取参数进行了优化，并对所建立的方法进行了线性、稳定性、精密度、重复性和回收率验证。与传统超声辅助萃取相比，IL-UAE方法具有更高的萃取效率，与药典方法相比，所需萃取时间更短，溶剂与固体比更小。此外，借助扫描电子显微镜（SEM）观察了甘草粉末萃取前后的微观结构，以探讨萃取机理。结果表明，离子液体作为绿色溶剂对从甘草中萃取黄酮苷和三萜皂苷是有效的。
