[Application of uncertainty assessment in NIR quantitative analysis of traditional Chinese medicine].

The near infrared (NIR) spectra of Liuyi San samples were collected during the mixing process and the quantitative models by PLS (partial least squares) method were generated for the quantification of the concentration of glycyrrhizin. The PLS quantitative model had good calibration and prediction performances (r(cal) 0.998 5, RMSEC = 0.044 mg · g(-1); r(val) = 0.947 4, RMSEP = 0.124 mg · g(-1)), indicating that NIR spectroscopy can be used as a rapid determination method of the concentration of glycyrrhizin in Liuyi San powder. After the validation tests were designed, the Liao-Lin-Iyer approach based on Monte Carlo simulation was used to estimate ß-content-γ-confidence tolerance intervals. Then the uncertainty was calculated, and the uncer- tainty profile was drawn. The NIR analytical method was considered valid when the concentration of glycyrrhizin is above 1.56 mg · g(-1) since the uncertainty fell within the acceptable limits (λ = ± 20%). The results showed that uncertainty assessment can be used in NIR quantitative models of glycyrrhizin for different concentrations and provided references for other traditional Chinese medicine to finish the uncertainty assessment using NIR quantitative analysis.

Establishment and quality assessment of tissue cultures in Glycyrrhiza uralensis Fisch.

In this study, seedling, callus, cell, and adventitious root of Glycyrrhiza uralensis Fisch. have been established. In order to find the best one for producing G. uralensis active constituents, triterpenoid saponins and flavonoids in native root and tissue cultures were determined, and the contents in different G. uralensis materials were analyzed using cluster analysis. The contents of triterpenoid saponins and glycyrrhizic acid in tissue cultures were much lower than that in native G. uralensis. The total flavonoids content we determined in adventitious root was 6.31 mg g(-1), which was close to that of native root (9.82 mg g(-1)). Based on the cluster analysis, we found that G. uralensis cultures were not suitable for production of glycyrrhizic acid, while adventitious root had a greater capability of flavonoids production comparing to seedling, callus, and cell.

[Investigation on medicinal plant resources of Glycyrrhiza uralensis in China and chemical assessment of its underground part].

OBJECTIVE: In order to find out the current situation of wild and cultivated resources of Glycyrrhiza uralensis, at the same time, the contents of glycyrrhizic acid and liquiritin were detected by HPLC. METHOD: Field investigation was carried out, and chemical composition of collected underground part was analyzed in laboratory. RESULT: The natural distribution range of wild G. uralensis in China has no significant change. We can still find its distribution in the distribution areas recorded ten years ago, but the intensity of species group has greatly changed. Estimated according to the survey data obtained by quadrat reserves and distribution (i.e., reserves per unit area) or cultivation area, that the current wild reserves is less than 500,000 tons and the less than 150,000 tons for cultivated. The analysis results of glycyrrhizic acid and liquiritin contents in 99 wild samples of collected underground part show that the average contents of glycyrrhizic acid and liquiritin were respectively 34.8, 17.3 mg x g(-1), of which 61.6% samples can reach the standard (not less than 20, 10 mg x g(-1)) marked by "Chinese Pharmacopoeia" (2005 edition); The average glycyrrhizic acid and liquiritin contents of cultivated samples were respectively 28.5, 15.3 mg x g(-1), which were much lower than the wild samples. CONCLUSION: We should enhance efforts in protecting the wild resources, strive to improve the quality of cultivated herbs, vigorously develop high-quality G. uralensis cultivation industries and promote farmers income to resolve the resource crisis, which is the reasonable way to achieve continuable use of G. uralensis resources.

Determination of glycyrrhizin in liqueurs by on-line coupled capillary isotachophoresis with capillary zone electrophoresis.

An on-line coupled capillary isotachophoresis-capillary zone electrophoresis method for the determination of glycyrrhizin in liqueurs is described. The optimised electrolyte system was 5 mM HCl+11 mM epsilon-aminocaproic acid+0.05% hydroxyethylcellulose+30% methanol (leading electrolyte), 5 mM caproic acid+30% methanol (terminating electrolyte) and 20 mM caproic acid+10 mM histidine+0.1% hydroxyethylcellulose+30% methanol (background electrolyte). Method characteristics, i.e., linearity (20-500 ng/ml), accuracy (recovery 99+/-4%), intra-assay repeatability (2%), intermediate repeatability (3.8%) and detection limit (8 ng/ml) were determined. Speed of analysis, low laboriousness, high sensitivity and low-running cost are the typical attributes of the capillary isotachophoresis-capillary zone electrophoresis method. Developed method was successfully applied to analysis of liqueurs with liquorice extract and some foods (sweets and food supplements) containing liquorice. Found levels of glycyrrhizin in liqueurs, sweets and food supplements varied between 1-16 mg/l, 850-1050 mg/kg and 1.6-1.8 g/kg, respectively.

A high performance liquid chromatography method for the simultaneous determination of arctiin, chlorogenic acid and glycyrrhizin in a Chinese proprietary medicine.

A high performance liquid chromatography (HPLC) method was developed for the simultaneous determination of arctiin, chlorogenic acid and glycyrrhizin in the tablets of a Chinese proprietary medicine named, "Yin Qiao Jie Du Pian". The analysis was performed by a reverse phase gradient elution, using an aqueous mobile phase (containing 0.4% acetic acid and 4.5% tetrahydrofuran) modified by acetonitrile and detection made simultaneously at three wavelengths. The method was validated for specificity, accuracy, precision and limits of detection and quantification. Tablets of seven commercial brands were analyzed and found to contain different amounts of the three bioactive markers. This raised the question of the quality and the efficacy of the products. The method developed can be used for the quality control of "Yin Qiao Jie Du" tablets.