ABSTRACT
A quantitative analytical method based on HPLC coupled with the charged aerosol detector (CAD) for quantitative analysis of multi-components with a single marker (QAMS) was established for simultaneous determinations of astragaloside Ⅰ, astragaloside Ⅱ, astragaloside Ⅳ, calycosin-7-O-β-D-glucoside, formononetin and 7,2'-dihydroxy-3',4'-dimethoxyisoflavan in Astragalus membranaceus. The separation was performed on an Agilent SB-C18 (150 mm×4.6 mm, 3.5 μm), with gradient elution using the mobile phase consisting of 0.05% formic acid solution and 0.05% formic acid acetonitrile at the flow rate of 1.0 mL·min-1. The column temperature was 35 ℃, and the injection volume was 20 μL. For CAD, the drift tube temperature was at 50 ℃. The contents of six components in A. membranaceus were determined by both external standard method (ESM) and QAMS, and then were compared. The results showed that chromatographic peaks were separated well and the linear ranges of astragaloside Ⅰ, astragaloside Ⅱ, astragaloside Ⅳ, calycosin-7-glucoside, formononetin and 7,2'-dihydroxy-3',4'-dimethoxyisoflavan were 0.113-2.250 mg·mL-1, 0.012-0.240 mg·mL-1, 0.004-0.080 mg·mL-1, 0.065-1.300 mg·mL-1, 0.005-0.100 mg·mL-1 and 0.007-0.150 mg·mL-1, respectively. The content ranges of astragaloside Ⅰ, astragaloside Ⅱ, astragaloside Ⅳ, calycosin-7-glucoside, formononetin and 7,2'-dihydroxy-3',4'-dimethoxyisoflavan were 0.306-0.922 mg·g-1, 0.053-0.183 mg·g-1, 0.015-0.092 mg·g-1, 0.069-0.823 mg·g-1, 0-0.098 mg·g-1 and 0.020-0.107 mg·g-1 in 20 batches of A. membranaceus, respectively. Using astragaloside Ⅱ as an internal reference, the relative correlation factors of astragaloside Ⅰ, astragaloside Ⅳ, calycosin-7-O-β-D-glucoside, formononetin, and 7,2'-dihydroxy-3',4'-dimethoxyisoflavan were calculated as 0.561, 0.835, 0.299, 0.796, and 0.799, respectively. The results were compared with those obtained by the external standard method to verify the feasibility, rationality and repeatability of QAMS method, and there was no significant difference in assay results between the two methods. In conclusion, the QAMS method is accurate and feasible, and could be used to determine the contents such as astragaloside Ⅰ, astragaloside Ⅱ, astragaloside Ⅳ, calycosin-7-glucoside, formononetin and 7,2'-dihydroxy-3',4'-dimethoxyisoflavan, and it can be used for quality control of A. membranaceus.
ABSTRACT
A new method was developed for the chromatographic fingerprint analysis of Toosendan Fructus by HPLC coupled with the charged aerosol detector (CAD) in the present study. Samples were well separated on an Agilent ZOBAX SB C18 column (4.6 mm×250 mm, 5 μm) by gradient elution using acetonitrile and water containing 0.1% formic acid (v/v) at the flow rate of 1.0 mL·min-1. The column temperature was 30℃ and the injection volume was 5 μL. The nitrogen inlet pressure of the charged aerosol detector (CAD) was 35 psi, and the nebulizer chamber temperature was 35℃. In addition, the method of the chromatographic fingerprints combined with multivariate statistical analysis was effective and reasonable lead to an accurate classification of 20 batches of samples from different locations. The results showed that 28 common peaks were observed in the fingerprint and the samples were classified into three clusters. The established method was well validated, and showed high precision, good repeatability, and satisfactory stability. It may serve in the quality control and evaluation of Toosendan Fructus.
ABSTRACT
OBJECTIVE: To evaluate hepatoprotection in Nrf2/ARE oxidation/chemical stress defense pathwaycaused by isoliquiritigenin (Iso) based on analysis of bile acids using profile of bile acids. METHODS: High performance liquid chromatography coupled with quadrupole mass spectrometry (HPLC-MS/MS) was applied to determine the contents of all kinds of endogenous bile acids including free bile acids, taurine conjugates and glycine conjugates. By the luciferase reporter gene assay for screening Nrf2-ARE signal targeting molecular experiments in liquorice extract, isoliquiritigenin was capable of markedly activating Nrf2-driven gene expression, therefore it was used to evaluate hepatoprotection in Nrf2/ARE oxidation/chemical stress defense pathway. RESULTS: Based on the analysis using principle components analysis (PCA), partial least square-discriminant analysis (PLS-DA), Nrf2+/+, Nrf2-/- and Iso Nrf2+/+ groups could be distinguished from their Iso Nrf2-/- group, which suggested that the variance of the contents of bile acids could evaluate hepatoprotection caused by Iso. Bile acids of ursodeoxycholic acid (UDCA), chenodeoxycholic acid (CDCA), cholic acid(CA), sodium taurodeoxycholate hydrate (TDCA), deoxycholic acid (DCA), taurocholic acid(TCA) proved to be important corresponds to Iso induced liver protection according to analysis of partial least square-discriminant analysis (PLS-DA) and the statistical analysis showed that there were significant differences among the four groups. It indicated that UDCA, CDCA, CA, TDCA, DCA and TCA could be considered as sensitive biomarkers of Iso induced liver protection. CONCLUSION: This work can provide the base for the further research on the evaluation and mechanism of hepatoprotection caused by liquorice.