| Aim at the problem that how to identify different sources of licorice in practical application, we have studied the chemical constituents of licorice in this thesis, we have developed methods for quantifying the 12 chemical constituents in licorice, and fingerprints of different sources licorice. So that we can identify different sources licorice from the perspective of chemical characteristics. Based on the research above, we have proposed a draft quality standard of licorice.The main results are as follows:1. Studied on chemical constituents from the roots of Glycyrrhiza uralensis Fisch. Make the use of various column chromatography,36 compounds were isolated from the 95% and 50% ethanol extract of Glycyrrhiza uralensis Fisch.34 compounds had been identified. Betulinic acid (6),oleanolic acid (8) were isolated from Glycyrrhiza uralensis Fisch. for the first time. Docosyl caffeate (10),7,2',4'-trihydroxy-5-methoxy-3-arylcoumarin (20),hedysarimcoumestan B (32),hedysarimcoumestan E (33) were isolated from Glycyrrhiza for the first time.2. Developed methods for quantifying the 12 chemical constituents in licorice by HPLC and UPLC respectively. Developed a method for simultaneously quantifying four flavonoid glycosides including liquiritin apioside, liquiritin, isoliquiritin apioside and formononetin-7-O-β-D-glucoside in licorice at the wavelength of 265 nm; echinatin, isoliquiritigenin, licoarylcoumarin, glycycoumarin, kumatakenin, glycyrol, glycyrin and glycyrrhizic acid were quantified at the wavelength of 350 nm and 250 nm. Using the HPLC and UPLC analytical methods, determined the contents of 100 licorice samples collected from all over the country, and compare the results of the two methods, statistics showed that the two methods showed no significant difference, each can be accurate and reliable quantified the 12 ingredients of licorice and each method could be used for quality evaluation on liicorice. While each method had its own characteristics, HPLC was able to meet the daily use,UPLC method with a short analysis time and a high analysis efficiency, was suitable for high-throughput analysis.3. Established HPLC and UPLC fingerprints of different sources licorice respectively. Evaluated the similarity of the 100 licorice samples collected from all over the country by the software of "traditional medicine fingerprint similarity evaluation".4. Distinguished three kinds of authentic licorice. The chemical component indexes and the fingerprinting characteristics for distinguishing three kinds of authentic licorice. For identifying the different kinds licorice:base on the analysis of 100 licorice samples, a sample, of which the ratio of liquiritin apioside to.liquiritin(mg/g) was less than 2.0, was usually G. uralensis Fisch. Thus it could be distinguished from G. inflata Bat. and G. glabra L. with 97.2% accuracy. And a sample, of which the ratio of formononetin-7-O-β-D-glucoside to isoliquiritin apioside was more than 0.2, was usually G.glabra L, and which was less than 0.2, was usually G. inflata Bat.,which could be distinguished from G. inflata Bat and G. glabra L. The accuracy was 94.7%. Licoarylcoumarin glycycoumarin, kumatakenin, glycyrol and glycyrin which exist in G. uralensis Fisch. could not be found in G. inflata Bat. and G. glabra L. Therefor, by this mean, G. uralensis Fisch. could be distinguished from the other two species licorice. In addition, glycycoumarin had been identified as a specific component of G. uralensis Fisch. And this chromatographic peak had been identified in the fingerprint. In UPLC fingerprints and HPLC fingerprints at the wavelengths of 350 nm and 250 nm, the characteristic peaks of three kinds of authentic licorice had been found respectively, by which the statutable three species of licorice could be distinguished.5. Discriminated the licorice of different modes of production. Different modes of production licorice were identified from two angles:the content of 12 chemical components and the fingerprints of licorice. The wild, semi-wild and cultivated licorice from Inner Mongolia Hangjinqi, the total contents of the 12 components of the wild or semi-wild licorice(more than 50 mg/g) were higher than the cultivated licorice. However, due to smaller sample, we should study continuously for more samples; The similarity evaluation results of three fingerprints show that:In addition to the cultivated licorice at 350 nm wavelength, the fingerprint slightly lower than other production licorice, the similarity of semi-wild licorice and wild licorice are good.At 250 nm wavelength, the similarity of three production licorice were also good, we can not distinguish the three modes of licorice on the fingerprint.The result on the wild and cultivated licorice from 8 habitats showed that the content of 12 chemical components of cultivated licorice were less than the content of wild licorice. T test result showed that very significant difference (P<0.01) was shown in the level of 8 content between cultivated and wild licorice, such as liquiritin apioside, liquiritin, formononetin-7-O-β-D-glucoside, isoliquiritin apioside, licoarylcoumarin, glycycoumarin, glycyrin, glycyrrhizic acid; significant differences (P<0.05) had been shown in the level of isoliquiritigenin and glycyrol; the level of echinatin and kumatakenin showed no significant difference (P>0.05). The fingerprints of wild and cultivated licorice showed high similarity. They could not be distinguished by fingerprint.6. Discriminated the licorice of different habitats. Respectively, licorice of different habitats were identified by two methods of chemical constituents and fingerprints. The determination of chemical compositions showed that the level of 12 kinds of chemical compositions of the 8 habitats licorice were different. The level of echinatin and glycyrrhizic acid showed very significant difference (P<0.01); the level of liquiritin showed significant difference (P<0.05). Similarity of fingerprints of different habitats licorice showed that at 350 nm wavelength, fingerprints of different habitats licorice were very similar; at 250 nm wavelength, only the fingerprint of Ningxia licorice shows lower similarity than others, while the other licorice fingerprints showed very high similarity. In this study, licorice of different habitats could not be distinguished by fingerprint.7. Developed a draft revision of licorice quality standard. A method for the identification of three species licorice had been established based on the chemical composition characteristics and the fingerprint, which also provided a reference for the improvement of licorice quality standard.The research characteristic and innovation of this thesis are as follows:(1) The chemical constituents from the roots of Glycyrrhiza uralensis Fish. were studied and 4 compounds were isolated from Glycyrrhiza and 2 compounds were isolated from Glycyrrhiza uralensis Fish. for the first time;(2) The determination method for 12 chemical components of licorice could reflect more comprehensively chemical information and inferior quality of licorice.(3) Three kinds of authentic licorice were distinguished from the perspective of chemical characteristics, make sure of the chemical methods in identified the three kinds of authentic licorice.
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