Lin Zheng

Guiyang Medical University, Kuei-yang, Guizhou Sheng, China

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Publications (10)3.44 Total impact

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    ABSTRACT: The in vivo effects of traditional herbal medicines are generally mediated by multiple bioactive components. The main constituents of Polygonum orientale L. are flavonoids such as orientin, vitexin, cynaroside, and quercitrin. The aim of this study was to develop and validate a method for characterizing these flavonoids, in order to better understand the pharmacokinetics and pharmacodynamics of P. orientale L. We used ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) to analyze the flavonoids. After precipitation of the proteins with methanol, the flavonoids were separated on a BEH C18 column (50mm×2.1mm, i.d., 1.7μm) by using an elution gradient of acetonitrile. Flavonoid content was determined using the multiple reaction monitoring (MRM) mode at m/z 449.2→329.2 for orientin, m/z 433.2→313.0 for vitexin, m/z 449.2→287.1 for cynaroside, m/z 449.2→303.4 for quercitrin, and m/z 417.0→267.0 for the internal standard, puerarin. Pharmacokinetics was assessed after intravenous administration of P. orientale L. extracts (POE) in Beagle dogs at a dose of 22, 44, or 88mg/kg. Analysis of the standard curves by linear regression revealed high linearity over a 243-fold dynamic range for the four flavonoids (the lower limit of quantitation values were 4-21ng/mL). The relative standard deviations of intra- and inter-day measurements were less than 15.1%, and the method was accurate to within -8.7% to 7.2%; the extraction recoveries from dog plasma were 70.6-89.3%, 69.8-88.7%, 72.5-85.7%, and 71.0-79.1% for orientin, vitexin, cynaroside, and quercitrin, respectively. Our results suggest non-linear pharmacokinetic characteristics with rapid clearance of the flavonoids. In conclusion, UPLC-ESI-MS/MS is a rapid and sensitive method for simultaneous quantification of multiple flavonoids from POE in dog plasma and is suitable for pharmacokinetic studies of herbal medicines.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 03/2014; 957C:96-104. · 2.78 Impact Factor
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    ABSTRACT: Isomeric polyphenolic glycosides that possess regioisomeric O-acylated saccharide residues can be found in many medicinal plants and their preparations as well as some synthetic intermediates. The need for a pure and sufficient quantity of compounds for nuclear magnetic resonance measurements calls for a microanalytical method for their rapid differ entiation. In the current investigation, an electrospray ionization–tandem mass spectrometric method was developed for rapid differentiation of two pairs of regioisomeric acylated monosaccharides, quercetin-3-O-(3″-O-galloyl)-α-L-rhamnopyranoside and quercetin-3-O-(2″-O-galloyl)-α-L-rhamnopyranoside as well as quercetin-3-O-(3″-O-galloyl)-β-D-glucopyranoside and quercetin-3-O-(2″-O-galloyl)-β-D-glucopyranoside; the mechanisms governing their similar or differential fragmentations are also discussed. The work may facilitate the structural determination of these regioisomers and their analogs in pure form or in complex matrix.
    Spectroscopy Letters 01/2014; 47(1):19-23. · 0.67 Impact Factor
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    ABSTRACT: A simple and selective ultra performance liquid chromatography–electrospray ionization tandem mass spectrometry (UPLC–ESI-MS/MS) assay was developed for the determination of the human plasma protein binding of four bioactive flavonoids (such as orientin and vitexin) in Polygonum orientale. Protein precipitation was used for sample preparation. Equilibrium dialysis technique was applied to determine the plasma protein binding under physiological conditions. The separation was achieved through a Waters C18 column with a mobile phase composed of 0.1% formic acid in acetonitrile and 0.1% aqueous formic acid using step gradient elution at a flow rate of 0.35 mL/min. A Waters ACQUITY™ TQD system was operated under the multiple reaction monitoring (MRM) mode of positive electrospray ionization. All of the recovery, precision, accuracy and stability of the method met the requirements. Good correlations (r>0.99) of the four compounds were found, which suggested that these compounds can be simultaneously determined with acceptable accuracy. Results showed that the plasma protein bindings of the four bioactive flavonoids were in the range of 74–89% over the six concentrations studied. The binding parameters containing protein binding affinity, protein binding dissociation constant, and protein binding site were studied. The maximum ability to bind with protein was also determined in the assay in order to understand the drug-protein binding of each compound better.
    Journal of Pharmaceutical Analysis. 01/2013; 3(5):376–381.
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    ABSTRACT: To study the protective effect of flowers, branch with leaves and main stem of Polygonum orientale on H9c2 myocardial cells oxidative injury induced by H202 and discuss its efficacious substance foundation of anti-myocardial ischemia. UPLC fingerprint was established for flowers, branch with leaves and main stem of P. orientale, and the chromatographic peak was identified. Meanwhile, the protective effect of composites of flowers, branch with leaves and main stem of P. orientale in different proportions on myocardial cells oxidative injury was observed (with MTT method as indicators of concentration screening and cell livability) and MDA were detected. The correlation analysis was made between activity information of composites and chemical information of UPLC fingerprint to infer efficacious substance foundation. Branch with leaves and flowers from Polygonum orientale showed a protective effect on H9c2 myocardial cells oxidative injury. According to the study on spectrum-activity relationship, peak 3-5, 11-14, 18-19, 21-25 showed a positive correlation with their antioxidant activities. This study determined activity of Polygonum orientale on anti-oxidative injury, laying an experimental foundation for in-depth study and development of P. orientale herbs.
    Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 09/2012; 37(17):2585-8.
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    ABSTRACT: To establish a UPLC-MS/MS analysical method for simultaneous determination of concentrations of isoorientin, scutellarin and cynaroside in rat plasma and to study their pharmacokinetic characteristics after intravenous injection of 3 doses of Fufang Hongcao in rats. Acidified plasma samples were precipitated for protein with methanol. Waters Acquity BEH C18 column was adopted for spectrum, with mobile phase as 0. 1% formic acid acetonitrile-0. 1% formic acid-water gradient elution. Detection was carried out by the multiple reaction monitoring (MRM) positive ion mode with ESI ionization source. Three flavonoids show a good linear relationship, with the extraction recovery ranging between 78.56% and 101.91% and a high intra-and inter-day precisions and accuracy. The MRT of the three flavonoids were all lower than 22 min in rats. The above men tioned method is so specific, rapid, sensitive that it is suitable for pharmacokinetic studies of Fufang Hongcao injection in rats.
    Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 02/2012; 37(4):529-32.
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    ABSTRACT: To establish a UPLC method for simultaneous determination of seven chemical markers (gallic acid, catechin, alphitonin, taxifolin, kaempferol-3-O-beta-D-glucoside, quercetin-3-O-alpha-L-rhamnoside, and kaempferol-3-O-alpha-L-rhamnoside) of the flowers of Polygonum Oriental collected from Guizhou province. Separation was performed at 45 degrees on a ACQUITY UPLC BEH C18 column (2.1 mm x 150 mm, 1.7 microm) with a gradient solvent system of 0.1% formic acid in acetonitrile-0.1% aqueous formic acid as the mobile phase. The flow rate was 0.3 mL x min(-1), the detection wavelength was 280 nm, and the sample injection volume was 1 microL. In the selected linear range, all calibration curves of the seven chemical markers showed good linearity. The recoveries (n = 6) were in the range of 97.90% -101.4% and RSD were less than 3.8%. The results showed that the seven compounds contained in all the samples of the flowers of P. orientale can be chosen as their chemical markers and that this UPLC-PAD method is simple, reliable and suitable for the quality control of the flowers of P. orientale. However, the chemical markers may be present at different levels for samples collected in different areas and at different times. A collection time of mid-to-late August with relatively high content of the chemical markers was suggested for the flowers of P. orientale.
    Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 11/2011; 36(22):3141-5.
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    ABSTRACT: To establish an UPLC-MS/MS method for simultaneous determination protocatechuic acid, isoorientin and scutellarin in rat tissues after a single intravenous administration of Compound Hongcao for injection, and investigate the distribution character of the three compounds. Three compounds were simultaneously determined by UPLC with Waters Acquity UPLC BEH C18 column. The mobile phase, consisting of acetonitrile and 0.1% aqueous formic acid, was programmed as a linear gradient. The flow rate was 0.35 mL x min(-1). The compounds were ionized in the electrospray ionization ion source of the mass spectrometer and detected in the multiple reaction model. The tissue samples were homogenated and the suspension were extracted with methanol for further use. The relationship between the concentration and the peak areas of the three compounds were all linear (r > 0. 99). The precisions, accuracy, extract recoveries and stability of the analytes meet the requirements. The method has been successfully applied to tissue distribution studies of the three compounds. The present study demonstrates that the higher tissues concentration of three components were obtained in kidney, lung and heart after a single intravenous administration of ones. The present study demonstrates that the three compounds have unequal distribution character. It was showed that the three compounds were mainly distributed in abundant blood-supply tissues such as kidney, lung and heart. It was also found that protocatechuic acid, isoorientin and scutellarin exceretion rapidly and have no long-term accumulation. The method was shown to be effective, convenient, and suitable for simultaneous study the distribution of the three compounds in rat.
    Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 11/2011; 36(22):3189-93.
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    ABSTRACT: To identify the compounds in herb of Polygonum orientale by ultra-performance liquid chromatography with PDA and electrospray ionization tandem mass spectrometry (UPLC-PDA-ESI/MS). The chromatographic separation was carried out at 45 degrees C on a BEH C18 column (2.1 mm x 100 mm, 1.7 microm) eluted in the gradient program. The mobile phase consisted of acetonitrile and water containing 0.1% formic acid. The detecion of PDA was set between 190 nm and 400 nm. The mass spectra was obtain by Waters ACQUITY triple quadrupole tandem mass spectrometer in negative ion mode with ion spray voltage 3 kV. The temperature of the source and desolvation were set at 120 degrees C and 350 degrees C, separately. Nitrogen was used as the desolvation gas (750 L h(-1)) and cone gas (50 L h(-1)). For collision induced dissociation (CID), argon was used as the collision gas at a flow rate of 0.18 mL min(-1). The mass range recorde, m/z 100-1000. One phenolic acid, eleven flavonoids were well separated and identified by the method. The method is simple and rapid for the compound identification in the herb of P. orientale.
    Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 01/2011; 36(1):57-9.
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    ABSTRACT: To study the rationality of extraction prosess for the Ligusticum chuanxiong in Hongye Xintong Soft Capsule by super critical fluid extraction(SFE). Conditions for the extraction were optimized by orthogonal experimental design as guided by the extraction rate and content of ligustilid in the extract; Combined with the experiment of rats ligated the left coronary artery, the two compounds containing different extracts (steam distillation and SFE) were compared to determine the extraction prosess. The best extraction conditions were established as following: pressure 30 MPa, temperature 50 degrees C, extracting time 4 h, separate pressure 10 MPa. separate temperature 40 degrees C. Compared with steam distillation, the compound containing SFE extract showed stronger protective effects on rats ligated the left coronary artery. Super critical fluid can extract active ingredients in Ligusticum chuanxiong effectively.
    Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 02/2009; 34(2):161-4.
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    ABSTRACT: To establish the fingerprint detecting standard of Compound Hongcao Injection by reversed phase high performance liquid chromatography. The chromatographic conditions were as follows: an Inersil-ODS-3 column was used; the mobile phases (acetontrile and 0.1% phosphoric acid) with gradient elution; the flow rate 1.0 mL x min(-1) and the UV absorbance detection at 300 nm. Under the same selected chromatographic conditions, the HPLC fingerprints of raw drugs and their intermediate, finished products were obtained with good separation and correlation according to the technical requirements of fingerprint on Injection of Chinese traditional medicine. 17 common peaks as well as their retention times and peak area ratios on HPLC fingerprint can be used as the important parameters of the quality control for Compound Hongcao Injection.
    Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 04/2005; 30(6):440-2.