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Xu C.-L.,Nanjing University | Chen J.-W.,Nanjing University | Chen J.-W.,Jiangsu Key Laboratory for TCM Formulae Research | Ju W.-Z.,Nanjing University of Traditional Chinese Medicine | And 7 more authors.
Biomedical Chromatography | Year: 2012

A rapid, sensitive and specific method using liquid chromatography with tandem mass spectrometric detection (LC-MS) was developed for the analysis of sauchinone in rat plasma. Di-O-methyltetrahydrofuriguaiacin B was used as internal standard (IS). Analytes were extracted from rat plasma by liquid-liquid extraction using ethyl acetate. A 2.1mm i.d. × 150mm, 5μm, Agilent Zorbax SB-C18 column was used to perform the chromatographic analysis. The mobile phase was methanol-deionized water (80:20, v/v). The chromatographic run time was 7min per injection and the flow-rate was 0.2mL/min. The tandem mass spectrometric detection mode was achieved with electrospray ionization interface in positive-ion mode (ESI+). The m/z ratios [M+Na]+, m/z 379.4 for sauchinone and m/z 395.4 for IS were recorded simultaneously. Calibration curve were linear over the range of 0.01-5μg/mL. The lowest limit of quantification was 0.01μg/mL. The intra-day and inter-day precision and accuracy of the quality control samples were 2.94-9.42% and 95.79-108.05%, respectively. The matrix effect was 64.20-67.34% and the extraction recovery was 93.28-95.98%. This method was simple and sensitive enough to be used in pharmacokinetic research for determination of sauchinone in rat plasma. © 2011 John Wiley & Sons, Ltd. Source

Chen Y.,Nanjing University | Chen J.-W.,Nanjing University | Chen J.-W.,Jiangsu Key Laboratory for TCM Formulae Research | Liu S.-J.,Nanjing University of Traditional Chinese Medicine | And 6 more authors.
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2012

A liquid chromatography-mass spectrometry method has been developed and validated for the quantification of bullatacin, a bistetrahydrofuran annonaceous acetogenin, in rat plasma. Squamostatin-A was selected as the internal standard. Analytes were extracted from rat plasma by liquid/liquid extraction using ethyl acetate with high efficiency. The chromatographical separation was performed on an Agilent Zorbax SB-C 18 column (150mm×2.1mm, 5μm). The mobile phase consisted of methanol and deionized water (95:5, v/v) containing 0.01% (v/v) formic acid. The chromatographic run time was 7min per injection and flow rate was 0.2mL/min. The retention time was 3.22 and 5.23min for internal standard and bullatacin, respectively. The elutes were detected under positive electrospray ionization and the target analytes quantified by selected ion monitoring mode (645.9m/z for bullatacin and 661.9m/z for squamostatin-A). The method was sensitive with the limit of quantitation at 0.5ng/mL in 100μL of rat plasma. Good linearity (r 2=0.9998) was obtained covering the concentration of 0.5-2000ng/mL. The intra- and inter-day assay precision ranged from 3.2 to 8.7% and 2.7 to 9.2%, respectively. In addition, the stability, extraction recovery and matrix effect involved in the method were also validated. This method was applied to measure the plasma bullatacin concentrations after a single tail vein intravenous administration of bullatacin in rats. © 2012 Elsevier B.V. Source

Chen H.-j.,Nanjing University | Li X.,Nanjing University | Li X.,Jiangsu Key Laboratory for Chinese Materia Medica Processing | Chen J.-w.,Nanjing University | And 2 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2010

A high performance liquid chromatography method coupled with diode array detection (HPLC-DAD) was developed for simultaneous determination of five major active flavonoids, two aristolactams and four main lignans in Saururus chinensis, namely rutin (1), isoquercitrin (2), quercetin-3-O-β-d-glucopyranosyl (1 → 4)-α-l-rhamnoside (3), quercitrin (4), quercetin (5), aristolactam A II (6), sauristolactam (7), dihydroguaiaretic acid (8), sauchinone (9), licarin A (10) and licarin B (11). The analysis was performed on an Agilent Eclipse XDB C18 column (4.6 mm × 150 mm, 5 μm) with gradient elution of 0.4% aqueous phosphoric acid and acetonitrile. The detection wavelengths were 280 and 360 nm. All calibration curves showed good linearity (r2 > 0.9991) within test ranges. The method was reproducible with intra- and inter-day variation less than 3.2%. The recovery of the assay was in the range of 95.1-103.9%. The validated method was successfully applied for the analysis of the eleven bioactive compounds in seven samples from different harvesting seasons and significant variations were revealed. The results indicated that the developed method can be used as a suitable quality control method for S. chinensis and it should be harvested in August (fruiting period) for Jiangsu cultivation regions, taking the yield into consideration, with the highest amounts of lignans, relative higher amounts of flavonoids and lower amounts of aristolactams. © 2009 Elsevier B.V. All rights reserved. Source

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