Supercritical Carbon Dioxide Extraction of Glycyrrhizin from Licorice Root

摘要

As the development of the natural medicine, the glycyrrhizin extracted from the licorice root was found to have potential therapeutic value in the treatment of several diseases, especially available for anti-SARS virus [1-2]. Therefore, the purpose of this work was to find an optimal method to extract and refine the glycyrrhizin. In this work, the extraction of glycyrrhizin by means of organic solvents and supercritical carbon dioxide (SC-CO_2) was investigated. The SC-CO_2 extraction apparatus was designed and set up by our own laboratory. The experimental conditions was as follows: pressure 10MPa-30MPa, temperature from 30°C to 60°C, CO_2 flow rate about 10kg/h. The constitution of the solvent, and the particle size were all discussed in order to obtain the maximum extraction yield. The extraction of glycyrrhizin from licorice root with supercritical carbon dioxide was also compared with conventional extraction methods. Those methods include the extraction at room temperature (ERT), the traditional Soxhlet extraction, and the heat reflux extraction. The results show that the yield obtained by SC-CO_2 extraction was similar to that obtained by conventional solvent extraction. But the quality of the production extracted by SC-CO_2 was better than that of the production extracted by other methods. Subsequently, HPLC was used to analyze the chemical compositions of these productions.