微波辅助提取石蒜和虎杖中有效成分的热力学机理研究

采用微波辅助提取(MAE)技术研究了石蒜和虎杖两种不同植物中石蒜碱、力可拉敏和加兰他敏以及白藜芦醇和大黄素提取过程的热力学机理. 以溶剂回流提取方法(SRE)作为对比, 采用一种简单的测定提取分配系数的方法, 计算了这些组分在两种提取过程中的热力学函数ΔH0, ΔS0和ΔG0, 对其化学结构与极性以及在MAE过程中的热力学行为进行了讨论, 并用扫描电镜法观察了MAE和SRE提取后样品的细胞结构. 结果表明, 石蒜和虎杖的提取是一个吸热熵增的过程, 微波的作用导致石蒜和虎杖细胞结构发生显著变化, 使MAE热力学函数变化较大, 其提取过程的热力学行为特征与SRE明显不同, 但提取效率提高.

Investigation of Thermodynamic Mechanism for Extraction of Active Constituents in Lycoris radiata and Rhizma Polygoni Cuspidati Using Microwave-assisted Extraction

The extraction mechanism of lycorine, lycoramine, galanthamine and resveratrol, emodin in two dissimilar plants namely Lycoris radiata and Rhizma Polygoni Cuspidati was investigated by using the closed microwave-assisted extraction(MAE), respectively. Solvent reflux extraction(SRE) was also performed for comparison study. A simple model was applied to calculate partition coefficients K, ΔH0, ΔS0 and ΔG0 of the constituents determined for MAE and SRE, and their thermodynamic behavior, chemical structures and polarities were further discussed. With the observation of scan electron microscopy, the cell microstructures of Lycoris radiata Herbert and Rhizma Polygoni Cuspidati were changed in MAE process. The results show that MAE and SRE were endothermic and entropy increase processes, the effects of microwave on cell led thermodynamic functions to greater change, MAE with the higher yields was more spontaneous than SRE.