College of Chemistry and Chemical Engineering, Guizhou University, Guiyang, 550025, China.
College of Chemistry and Chemical Engineering, Guizhou University, Guiyang, 550025, China.
J Chromatogr A. 2020 Sep 27;1628:461446. doi: 10.1016/j.chroma.2020.461446. Epub 2020 Aug 1.
Ionic liquids, as tuneable, highly soluble, non-flammable, non-volatile and reusable extractants, have attracted extensive attention in the extraction of flavonoids from plants. In the present work, novel dual-chain imidazolium-derived ionic liquids were synthesized by a simple and efficient method and characterized (NMR spectroscopy, thermal stability, viscosity, conductivity, and polarity). Then, the imidazolium ionic liquids with different cation were used in the microwave-assisted extraction of flavonoids from Pinus massoniana Lamb. The results showed that the ionic liquid [Bmbim]Br, with a relatively low viscosity, conductivity and π* as well as a relatively large β, offered the best extraction efficiency and selectivity for flavonoids. Subsequently, the parameters of the extraction procedure for flavonoids were optimized as follows: extraction temperature of 80 °C, extraction time of 60 min, microwave power of 300 W, solid-liquid ratio of 1:20, and [Bmbim]Br solution concentration of 1.0 mol/L. The extraction yield of total flavonoids was 41.07 mg/g. Finally, a recovery method of the ionic liquid had been demonstrated, and the recovery rate of ionic liquid was 73.14%.
离子液体作为可调谐、高溶解、不可燃、不挥发和可重复使用的萃取剂，在植物中黄酮类化合物的提取中引起了广泛关注。在本工作中，通过一种简单有效的方法合成了新型的双链咪唑衍生离子液体，并对其进行了表征（NMR 光谱、热稳定性、粘度、电导率和极性）。然后，将不同阳离子的离子液体用于微波辅助从马尾松中提取黄酮类化合物。结果表明，粘度、电导率和π*相对较低，β相对较大的离子液体[Bmbim]Br 对黄酮类化合物具有最佳的提取效率和选择性。随后，优化了黄酮类化合物提取过程的参数，如下：提取温度 80°C，提取时间 60min，微波功率 300W，固液比 1:20，[Bmbim]Br 溶液浓度 1.0mol/L。总黄酮的提取率为 41.07mg/g。最后，还展示了离子液体的回收方法，离子液体的回收率为 73.14%。
