甘草中甘草酸的多级逆流提取技术研究

Multistage Countercurrent Extraction Techniques for Extraction of Glycyrrhizic Acid from Licorice

摘要:

研究利用多级逆流技术提取甘草酸的新方法。采用正交试验考察提取温度、提取时间、级数和液固比对提取效率的影响，确定多级逆流提取甘草酸的最佳工艺条件；在优选出的最佳工艺条件下，考察了提取溶剂对提取率的影响，并与室温冷浸法、超声波法、索氏提取法和微波提取法做了比较。结果表明：多级逆流提取甘草酸的最佳条件为提取温度70℃，单级提取时间60min，液比6，提取级数为5。在此最佳条件下，多级逆流提取的提取率高于室温冷浸44.3h、超声波提取40min、索氏提取4h、微波萃取54min的提取率。多级逆流提取具有快速、高效、节能、节约溶剂的特点，用于中草药有效成分的提取，值得推广应用。

Abstract:

Multistage countercurrent extraction (MCE) technique for extraction of glycyrrhizic acid (GA) from glycyrrhiza uralensis Fisch was studied in this paper. The effects of countercurrent extraction stages, temperature, extraction time and ratio of water/licorice on glycyrrhizic acid percentage extraction, which is defined as the ratio of mass of glycyrrhizic acid (GA) in the extracted solution and mass of licorice root, were investigated. The appropriate MCE conditions were obtained from the orthogonal test. The percentage extraction efficiency of GA was analyzed by high performance liquid chromatography (HPLC). The results showed that the effect of extraction temperature on percentage extraction of GA was the most remarkable factor and the stage is the least one. The optimum conditions of MCE are five stages extracting 60min for every stage under 60℃. The ratio of water/ licorice is 6∶1. In the optimal conditions, the yield of glycyrrhizic acid is higher than that of microwave-assisted extraction (MAE), ultrasonic extraction (USE), Soxhlet extraction (SHE) and extraction at room temperature (ERT) for 54min, 40min, 4h and 44.3h, respectively. Due to the high extraction efficiency and less time and solvent consuming, MCE is recommendable to the application of GA extraction from glycyrrhiza uralensis Fisch.