Studies On Separation And Purification Of Secondary Metabolites Of Licorice

Deeply and systematically researches had done to the extraction flavonoids and glycyrrhizic acid from licorice using ultrasonic-assisted extraction, purification flavonoids and glycyrrhizic acid through macroporous resin and extraction, purification glycyrrhizic acid from the licorice reside. Moreover, the methods of extraction and determination of polysaccharides and alkaloid from licorice was studied. (1) Decided the spectrophotometry and thin-layer colorimetry analysis conditions of the flavonoids and glycyrrhizic acid in general and system way. (2) Comparison of extraction techniques for the flavonoids was presented. The extracting conditions of flavonoids through ultrasonic-assisted extraction was studied, and obtained the better process conditions. The results showed the extractions of flavonoids was 4.82%. The optimum purification conditions of the flavonoids with macroporous resin AB-8 was obtained. With macroporous resin to adsorb and purify, the yield of flavonoids was 3.82% and the content was 66%. Further more, the antibiotic bioactivity in vitro of the extracted flavonoids was studied. The experiments showed the flavonoids had obvious antibiotic action against such pathogens as Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Bacterium aeruginosa, and the minimal inhibitory concentration(MIC) were 0.03125, 0.03125, 0.125, 0.03125 mg/mL respectively. (3) The extraction methods for the glycyrrhizic acid was researched. Studied the factors of glycyrrhizic acid through ultrasonic-assisted extraction, and obtained the better process condition. The results showed the extractions of glycyrrhizic acid was 6.42%. The optimum purification conditions of the glycyrrhizic acid with macroporous resin DA201 was obtained. With macroporous resin to adsorb and purify, the yield of glycyrrhizic acid was 4.86% and the content was 76%. The extraction and purification of glycyrrhizic acid from licorice residue was studied, and obtained the better process condition. It was shown the yield of flavonoids and glycyrrhizic acid was 3.62% and 3.61% respectively, and the content was 66.04% and 80.83% respectively. (4) Established the methods of extraction and determination of polysaccharides and alkaloid from licorice. The results showed the contents of polysaccharides was 3.21% and the total contents of alkaloid was 0.27%. The techniques of extraction and separation of effective components of licorice was investigated in this thesis, and obtained flavonoids and glycyrrhizic acid in one process through one group of raw material, and provided the strong base of theory and practice to develop licorice medicine with high quality and profits.