Effects Of Different Processing And Extraction Conditions On Content And Proportion Of The Principal Component Isomers In Licorice

The effects of different processing and extraction conditions on content and proportion of the principal component isomers in licorice were investigated in this paper.Chapter One: The general situation of licorice herbs and the principal component isomers was introduced. And the research progress of the method of licorice processing and glycyrrhizic acid extraction at home and abroad was reviewed. The objective and significance of the study were also clarified in this study.Chapter One: The effects and change rule of licorice processing conditions on the content and proportion of the principal component isomer 18α-glycyrrhizic acid(18α-Gly) and18β-glycyrrhizic acid(18β-Gly), and on the content of impurity during processing were studied. Effects of processing time,processing temperature on the content of each component of mixture of standard substances and licorice pieces, and on the proportion of principal component isomer were observed. The results showed that the principal component isomer18α-Gly, 18β-Gly partly resolved with the extended processing time and processing temperature. The total content of principal component was declined after processing. But the configuration of principal component isomers has not changed in the processing. The proportion of principal component isomer 18α-Gly, 18β-Gly remained constant. When processing temperature below 90 ℃,the effects of processing time,processing temperature on the content of the principal component and impurity in licorice pieces are not obvious.When heated to 140 ℃,the degradation of 18α-Gly,and 18β-Gly occurred with the extended processing time, and the content of principal component decreased significantly. The proportion of the principal component in licorice pieces was not affected by the processing time and the processing temperature. The principal component and impurity in licorice pieces were sensitive to each processing factor,which can be a part of the scientific evidences for completing Quality Control System of licorice.Chapter three: The effects of glycyrrhizic acid extraction conditions on the extraction ratio and the proportion of principal component isomer 18α-glycyrrhizic acid(18α-Gly) and18β-glycyrrhizic acid(18β-Gly) were studied. And the effects of extraction solvent(solventtype, ethanol concentration, concentration of ammonia), ultrasonic extracting time and extraction method on the extraction ratio and the proportion of principal component isomer18α-Gly and 18β-Gly were also observed. The results indicated that the extraction solvent,extraction time and extraction method influence the content of 18α-Gly and 18β-Gly obviously but had no effect on the proportion of 18α-Gly and 18β-Gly. The optimum extracting condition for glycyrrhizic acid is adding 60% ethanol which contains 0.5%ammonia and using ultrasonic extract for 1h.