离子液体微波辅助萃取川芎中内酯类化合物

Microwave-assisted Extraction of Lactone from Ligusticum Chuanxiong Hort Using Ionic Liquid

以离子液体1-丁基-3-甲基咪唑双三氟甲基磺酰亚胺鎓盐([Bmim]Tf2N)为萃取剂,采用微波辅助萃取法(MAE)对川芎中的洋川芎内酯I和H及藁本内酯的萃取进行了研究.考察了温度、时间、相比和原药粒径等因素对萃取效果的影响,比较了MAE和传统溶剂回流萃取法(SRE)的萃取率,并对萃取后的固体做了SEM研究.结果表明,萃取温度对萃取率影响显著,在180℃下对3种内酯类化合物均体现出良好的萃取效率;萃取在1min内达到平衡;固/液比为1/30～1/5g/mL和原药粒径0.096～0.25mm范围内对萃取效率没有显著影响;与SRE相比,MAE耗时短、效率高,对提高藁本内酯萃取效率尤为显著,提高达46%;由样品表面结构变化可见,MAE萃取的样品结构被破坏,有助于活性组分释放、提高萃取率.

A microwave-assisted extraction （MAE） method was used to extract Senkyunolide I, Senkyunolide H and Z-ligustilide from Ligusticum Chuanxiong Hort. Ionic liquid, 1-butyl-3-methylimidazolium bis（trifluoromethanesulfonyl）imide （[Bmim]Tf2N）, was employed as extractant. Influential factors such as system temperature, extraction time, phase ratio and particle size were examined. The yield of the three target ingredients was compared between MAE and solvent reflux extraction （SRE）, and the sample matrix was studied by SEM. The result shows that temperature is the key factor of extraction process, the best result is obtained at 180℃. Extraction equilibrium can be reached within 1 min. Phase ratio （solid/liquid） and particle size do not make contribution to the extraction efficiency within the limits of 1/30～1/5 g/mL for phase ratio and 0.096～0.25 mm particle sizes. Compared with SRE, MAE costs less time and gives higher extraction efficiency, an increase of 46% was reached for Z-ligustilide, because the structure of Ligusticum Chuanxiong Hort was damaged, as shown by SEM images, which was beneficial to the extraction of natural products.