The Study Of Correlation Between Structural Characteristics Of Glycyrrhiza Uralensis Fisch Root And Glycyrrhizinate Content

In this study,Glycyrrhiza Uralensis Fisch root materials were collected once a month from March to October in the traditional Chinese medicine planting base of pingyao county,Shanxi Province.In this study,for the first time,the transverse section microstructure of roots of Glycyrrhiza Uralensis Fisch in different months was observed by light microscope.Enzyme-linked immunosorbent assay(ELISA)was used to determine the activity of four key enzymes in the synthesis of triterpenoid saponins.High performance liquid chromatography(HPLC)was used to determine the change of glycyrrhizin contents and to explore the correlation among the three.The microscopic structure of the transverse section of the root in different months was observed by paraffin section method.It was found that the root of biennial Glycyrrhiza Uralensis Fisch had the characteristics of typical dicotyledons,mainly composed of pericytes and vascular tissues.With the advance of month,the number of pericortical layers gradually increased,especially the cork layer.In March,it was 3-4 layers,and in October,it increased to 5-7 layers.The vascular rays gradually developed,the number of catheters increased,and the aperture gradually increased.The overall trend of black accumulation is increasing,with a slight decrease in March to April,a large increase in June,and a significant increase in September and October.The epidermis and cortical tissue of the primary structure of the root were completely exfoliated in August.The activity of four key enzymes(HMGR,DXR,SE,CYP450)was determined by enzyme-linked immunoassay assay.The results showed that HMGR activity showed a decreasing-stable fluctuation-declining trend,DXR activity showed an increasing-stable fluctuation-rising trend,SE activity showed an increasing-fluctuating-rising trend,CYP450 activity was significantly higher than the other three enzymes(about 500 m U/L).The activity of four key enzymes was higher from May to August.The activity of the key enzymes in triterpenoid saponins synthesis was measured,and therate of glycyrrhizinate synthesis could be predicted,which provided a basis for the analysis of the synthesis law and content of triterpenoid saponins.The contents of glycyrrhizin were determined by HPLC.The results showed that the contents of glycyrrhizin from March to October and the control were 3.290,1.900,2.620,2.940,4.480,5.100,7.430,5.300 and 5.030respectively(mgg-1).The content of glycyrrhizin decreased slightly from march to April,gradually increased from April to September,reached the highest in September,and decreased slightly in October.The content of glycyrrhizin was slightly higher than the control group in August,and significantly higher than the control group from September to October,indicating that the quality of Glycyrrhiza Uralensis Fisch from September to October was better.During the growth and development of two-year Glycyrrhiza Uralensis Fisch,there was an obvious correlation among the root of transverse microstructure,the activity of the key enzyme for the synthesis of triterpenoid saponins and the change of glycyrrhizinate content: the secondary structure of Glycyrrhiza Uralensis Fisch began to form from March to April,and the black accumulation decreased slightly.Glycyrrhizin content decreased slightly.The changes are same.In June and July,Glycyrrhiza Uralensis Fisch root transport tissue development was more obvious,in June,the black accumulation increased more;In July,SE and CYP450 showed the highest enzyme activity,which promoted the synthesis of triterpenoid saponins.In July,glycyrrhizinate content increased rapidly,second only to September.The correlation among the three is obvious.In September and October,the secondary structure was completely formed,vascular rays and phloem parenchyma cells were very developed,and the black accumulation was significantly increased.The overall high activity of the four key enzymes from May to August indicates that this period is the preparation period for the synthesis of glycyrrhizin active components,which promotes the synthesis of glycyrrhizin and makes its content reach the highest level in September.In September,glycyrrhizinate content increasedthe fastest and the content was the highest.The correlation among the three is obvious.Therefore,the best harvest time of Glycyrrhiza Uralensis Fisch is from September to October,during which Glycyrrhiza Uralensis Fisch growth and development is completed,the glycyrrhizinate content is high,the Glycyrrhiza Uralensis Fisch quality is good.The results can provide a theoretical basis for the development and effective use of Glycyrrhiza Uralensis Fisch resources.