不同微波辅助法提取苦参生物碱的比较

Comparison of Extraction for Alkaloids from Sophora flavescens by Different Microwave Assisted Method

目的:比较密闭微波辅助提取法(PMAE)、聚焦微波辅助提取法(FMAE)及微波辐射-溶剂回流提取法(PMIRE)3种微波辅助方法用于提取苦参生物碱的差异,探讨PMAE,FMAE,PMIRE的提取过程及其微波作用机制。方法:以苦参碱与氧化苦参碱为目标物,采用HPLC测定,通过优化微波功率、提取温度、提取时间、药材颗粒度、固液比等试验因素,计算其热力学函数,电子扫描电镜观察药材表面结构变化。结果:与常规的回流提取(SRE)法相比,PMAE,FMAE,PMIRE的提取效率明显提高,其热力学函数ΔH°和ΔS°明显增大,ΔG°更小。微波作用能使药材表面结构发生细胞破壁,强化提取过程。结论:微波辅助提取苦参生物碱的提取效率均优于常规的溶剂回流提取法;微波辅助的方式、作用程度、提取过程不同,提取效率有较大差异;PMAE提取时间最短;PMIRE由于微波直接作用强,细胞破壁效果更好,提取率最高,且仪器设备简单,操作简便。

Objective： To compare differences of pressurized microwave-assisted extraction method （PMAE）, focused microwave-assisted extraction method （FMAE） and post microwave irradiated-reflux extraction method （PMIRE） in extracting alkaloids from Sophoraflavescens, and investigate extraction process and microwave mechanism of these 3 kinds of microwave assisted extraction methods. Method： With oxymatrine and matrine as target alkaloids, which were determined by HPLC, thermodynamic functions were calculated by optimizing microwave power, extraction temperature, extraction time, solid-liquid ratio, medicinal granule and other factors, surface structural change of herbs was observed by electronic scanning inicroscope. Result： Compared with conventional solvent reflux extraction （SRE）, extraction efficiency of PMAE, FMAE and PMIRE increased significantly, AH^and AS^of alkaloids increased obviously, but AG^became smaller. Microwave irradiation could enable cell wall of herbs surface structure to rupture, and strengthen extraction process. Conclusion： Extraction efficiency of alkaloids from S. flavescens with microwave assisted extraction was superior to SRE; Extraction efficiency had large differences by different microwave assisted manners, irradiation degree and extraction process; PMAE had shortest extraction time in the closed system; Because of strong microwave direct role, PMIRE had the best cell-rupture and extraction yield, and its equipment was simple and easy-operating.