微波辅助提取石蒜和虎杖中有效成分的动力学机理

以鳞茎药材石蒜(Lycoris radiata)和根茎药材虎杖(Rhizma Polygoni Cuspidati)作为研究对象,采用微波辅助提取(MAE)石蒜中的石蒜碱、力可拉敏和加兰他敏以及虎杖中的大黄素和白藜芦醇,研究了提取过程的动力学机理。分别对这5种组分在提取温度、提取时间、搅拌速度和颗粒度等因素影响下MAE过程的动力学行为和特征进行了探讨,并与常规的溶剂回流提取法(SRE)进行对比研究,采用扫描电镜观察了MAE和SRE提取后样品的表面细胞结构。结果表明,石蒜和虎杖的MAE提取过程具有明显不同的动力学特征,其机理分别基于内部扩散传质控制和细胞破壁引起的界面反应控制。与SRE相比,MAE能引起石蒜和虎杖的细胞结构发生显著变化,降低了表观活化能Ea,组分的表观速率常数明显增大。

Kinetic Mechanisms for the Extraction of Active Constituents in Lycoris Radiata and Rhizma Polygoni Cuspidati by Microwave-assisted Extraction

The kinetic mechanisms for the extraction of active constituents in dissimilar plants Lycoris radiata and Rhizma polygoni cuspidati by microwave-assisted extraction(MAE) were investigated.Lycorine,lycoramine and galanthamine in Lycoris radiate,resveratrol and emodin in Rhizma polygoni cuspidati were target constituents.The kinetic behaviors and characters in their MAE processes were studied,and the conventional solvent reflux extraction(SRE) was also performed for comparison study.With the help of scanning electron microscopy(SEM),the cell microstructures of the samples extracted by MAE and SRE of Lycoris radiata Herbert and Rhizma polygoni cuspidati were observed.The results showed that the apparent rate constants of the constituents for MAE were greater than SRE but their activation energies smaller.The MAE process of Lycoris radiata Herbert was based on the internal mass-transfer mechanism,and the MAE process of Rhizma polygoni cuspidati was a typical cell-rupture process.