Kaishun Bi

Simultaneous determination of berberine, palmatine and jatrorrhizine by liquid chromatography–tandem mass spectrometry in rat plasma and its application in a pharmacokinetic study after oral administration of coptis–evodia herb couple

A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to simultaneously determine berberine, palmatine and jatrorrhizine in rat plasma. After mixing with the internal standard (IS) tetrahydropalmatine, plasma samples were pretreated by protein precipitation with acetonitrile-methanol (1:2, v/v). Chromatographic separation was carried out on a C18 column using a mixture of water (containing 0.1% formic acid) and acetonitrile (30:70, v/v) as mobile phase. The detection was performed by selected reaction monitoring (SRM) mode via electrospray ionization (ESI) source operating in the positive ionization mode. The method was linear over the concentration range of 1.0-250.0 ng/mL for all components. The intra- and inter-day precision values were less than 14.6% and the deviations were within +/-4.0%. The fully validated LC-MS/MS method has been successfully applied to the pharmacokinetic study of berberine, palmatine and jatrorrhizine in rat plasma after oral administration of coptis-evodia herb couple. Three peaks were observed in both individual and mean plasma-concentration curves of berberine, palmatine and jatrorrhizine, which may be attributed to distribution re-absorption and enterohepatic circulation.

Plasma metabolic profiling of Alzheimer's disease by liquid chromatography/mass spectrometry.

OBJECTIVES The identification of Alzheimers disease (AD) biomarkers may allow for a less invasive and more accurate diagnosis as well as serve as a predictor of future disease progression and treatment response. The aim of this study was to map potential biomarkers in plasma for AD. DESIGN AND METHODS Plasma metabolic perturbations between AD and healthy old person were investigated using ultra performance liquid chromatography/mass spectrometry (UPLC/MS) and metabonomics approach. The principal component analysis (PCA) of UPLC/MS spectra showed that metabolic changes between two groups. RESULTS The PCA of UPLC/MS spectra showed that metabolic changes observed between AD and control were clear. Nine potential biomarkers in correlation with the extent of AD were found. CONCLUSIONS Based on PCA, several potential biomarkers (LPCs, sphingosine and tryptophan) were found and further identified by the following LC/MS/MS analysis. All of them could be the potential early markers of AD.

Simultaneous determination of baicalin, wogonoside, baicalein, wogonin, oroxylin A and chrysin of Radix scutellariae extract in rat plasma by liquid chromatography tandem mass spectrometry

A liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous determination of baicalin, wogonoside, baicalein, wogonin, oroxylin A and chrysin in rat plasma, using naringin as an internal standard. After acidifying with HCl, plasma samples were pretreated by liquid-liquid extraction with acetone. Chromatographic separation was accomplished on a Hypersil Gold-C(18) analytical column (2.1×150 mm, 5 μm) utilizing a gradient elution profile and a mobile phase consisting of (A) 0.1% formic acid in water and (B) acetonitrile. Detection was performed by multiple reaction monitoring (MRM) mode using electrospray ionization in the positive ion mode. All analytes showed good linearity over the investigated concentration range (r>0.9900). The lower limit of quantification was 0.5 ng/ml for baicalin, wogonoside, wogonin and oroxylin A, and 1.0 ng/ml for baicalein and chrysin. Intra-day and inter-day precisions (RSD%) were less than 15% and accuracy (RE%) ranged from -6.7% to 5.8%. The validated method was successfully applied to investigate the pharmacokinetics of the major flavonoids of Radix scutellariae extract after oral administration to rats.

Simultaneous determination of 13 bioactive compounds in Herba Artemisiae Scopariae (Yin Chen) from different harvest seasons by HPLC–DAD

Herba Artemisiae Scopariae is a Chinese herbal medicine widely used for the remedy of liver diseases. A high performance liquid chromatography method coupled with diode array detection was developed to simultaneously determine 13 different bioactive compounds in Herba Artemisiae Scopariae (Yin Chen) including chlorogenic acid (1), 6,7-dihydroxycoumarin (2), caffeic acid (3), 4-hydroxyacetophenone (4), scopoletin (5), rutin (6), hyperoside (7), isoquercitrin (8), scoparone (11), 7-methoxycoumarine (12) and quercetin (13). By using four different wavelengths in the HPLC analysis, the developed method was able to determine the bioactive compounds with excellent resolution, precision and recovery. The method was applied to determine the amounts of the bioactive compounds in nine samples from different cultivated regions and harvest seasons in China, and significant variations were revealed. Chlorogenic acid was the most abundant among the analyzed compounds. The samples harvested in the spring contained higher contents of chlorogenic acid than those collected in other seasons. Other phenolic acids as caffeic acid, 3,5-dicaffeoylquinic acid, 4,5-dicaffeoylquinic acid and 4-hydroxyacetophenone accumulated at much higher amounts in about May to July. The samples analyzed contained a much lower level of the amount of other flavonoids and coumarins as rutin, hyperoside, isoquercitrin and scoparone.

Simultaneous determination of seven bioactive components in Oolong tea Camellia sinensis: quality control by chemical composition and HPLC fingerprints.

A simple and reliable method of high-performance liquid chromatography (HPLC) was developed for the quality control of oolong tea (the dry leaves of Camellia sinensis ): the quality control included the HPLC fingerprint and the quantitative determination of seven bioactive compounds chemicals, namely, (-)-gallocatechin, (-)-epigallocatechin, (-)-epigallocatechin gallate, caffeine, (-)-epicatechin, gallocatechin gallate, and (-)-epicatechin gallate. The developed analyses of the chemicals excelled in quantifying the chemicals in oolong tea. The chemical fingerprint of oolong tea was established using the raw materials of three main production sites in China, that is, Fujian (southern and northern parts), Taiwan, and Guangdong. The fingerprints from different cultivated sources were analyzed by hierarchical cluster analysis, similarity analysis, principal component analysis (PCA), analysis of variance (ANOVA), and discriminant analysis. The results indicated that the combination of chromatographic fingerprint and quantification analysEs could be used for the quality assessment of oolong tea and its derived products.

Simultaneous determination of catecholamines and their metabolites related to Alzheimer's disease in human urine

A simple and specific high-performance liquid chromatography method coupled with fluorescence detection (HPLC-FL) has been developed for the simultaneous determination of L-3,4-dihydroxyphenylalanine, norepinephrine, dopamine, epinephrine and 3,4-dihydroxyphenylacetic acid in human urine. The samples were derivatized by 1,2-diphenylethylenediamine with isoprenaline as internal standard. The factors affecting the fluorescence yield were investigated, including the reaction and separation conditions. The catecholamine derivatives were separated on a Kromasil C(18) column with methanol and sodium acetate buffer as mobile phase. The limits of detection for all catecholamines ranged from 0.2 to 1.1 ng/mL. The linear ranges were from 2.5 to 200 ng/mL except 3,4-dihydroxyphenylacetic acid from 5 to 200 ng/mL. The intra- and interday RSDs for all catecholamines were 1.0-8.0 and 2.1-14%, respectively. The method was successfully applied to determine the catecholamines in human urine from 14 Alzheimers disease patients and 14 healthy volunteers. It was concluded that the mean levels of catecholamines in urine of Alzheimers disease patients were all lower than those in healthy volunteers. The cluster analysis and independent samples T-test were used to distinguish the Alzheimers disease patients and healthy volunteers.

Simultaneous determination of naringin, hesperidin, neohesperidin, naringenin and hesperetin of Fractus aurantii extract in rat plasma by liquid chromatography tandem mass spectrometry.

A liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous determination of naringin, hesperidin, neohesperidin, naringenin and hesperetin in rat plasma, using liquiritin as the internal standard. Plasma samples extracted with a solid-phase extraction procedure were separated on a Zorbax SB-C18 analytical column (2.1 mm × 150 mm, 5 μm) and detected by electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode. The calibration curves were linear over the range of 3.0-600 ng/ml for naringin, 0.5-100 ng/ml for hesperidin, 3.5-700 ng/ml for neohesperidin, 5.0-1000 ng/ml for naringenin and hesperetin, respectively. The lower limits of quantification were 0.5 ng/ml for naringin, hesperidin, naringenin and hesperetin, and 0.35 ng/ml for neohesperidin. Intra- and inter-day precision (RSD%) was less than 15% and accuracy (RE%) ranged from -3.3% to 4.8%. The validated method was successfully applied to investigate the pharmacokinetics of the major flavanones of Fructus aurantii extract after oral administration to rats.

Dispersive liquid–liquid microextraction coupled with high‐performance liquid chromatography‐diode array detection for the determination of N‐methyl carbamate pesticides in vegetables

This paper described a simple, rapid and efficient method for the determination of N-methyl carbamate pesticides in tomato, cucumber, carrot and lettuce samples by dispersive liquid-liquid microextraction coupled with HPLC-diode array detection. Some experimental parameters that influenced the extraction efficiency, such as types and volumes of extraction and disperser solvents, extraction time and salt effect were examined and optimized. Under optimum conditions, the LOD of the method were 0.5-3.0 μg/kg depending on the compounds and the kind of vegetables. The linearities of the method were obtained in the range of 10.0-300 μg/kg for aldicarb, MTMC, carbofuran and carbaryl, and 20.0-600 μg/kg for isoprocarb, with the correlation coefficients ranging from 0.9921 to 0.9993. The RSD varied from 2.9 to 7.5% (n=5). The recoveries of the method for the five carbamates from vegetable samples at two different spiking levels were ranged from 77.8 to 98.2%. Results showed that the method we proposed can meet the requirements for the determination of N-methyl carbamate in vegetable samples and was finally applied to the analysis of target pesticides in vegetable samples taken from local markets.

Pharmacokinetic study of matrine, oxymatrine and oxysophocarpine in rat plasma after oral administration of Sophora flavescens Ait. extract by liquid chromatography tandem mass spectrometry.

A rapid, sensitive and selective high-performance liquid chromatography tandem mass spectrometric method (HPLC-MS) has been developed and validated for the simultaneous determination of matrine (MT), oxymatrine (OMT) and oxysophocarpine (OSP) in rat plasma after oral administration of Sophora flavescens Ait. extract using pseudoephedrine hydrochloride as an internal standard (I.S.). The three analytes were extracted from the plasma samples by liquid-liquid extraction with chloroform. The chromatographic separation was accomplished on a Kromasil C18 column (150 mm x 4.6 mm). Detection was performed on a single quadrupole mass spectrometer by selected ion monitoring (SIM) mode via electrospray ionization (ESI) source. The total run time was 12 min between injections. The assay had a lower limit of quantification of 1.0 ng/ml for MT, 2.0 ng/ml for OMT and 2.0 ng/ml for OSP using 200 microl of plasma. The calibration curves were linear in the measured range. The overall precision and accuracy for all concentrations of quality controls and standards was better than 15%. The proposed method enables unambiguous identification and quantification of MT, OMT and OSP in vivo. This was the first report on determination of the major quinolizidine alkaloids in rat plasma after oral administration of Sophora flavescens Ait. extract. The results provided a meaningful basis for evaluating the clinical applications of the herbal medicine.

Metabonomic study of biochemical changes in the urine of Morning Glory Seed treated rat.

This paper was designed to study metabonomic characters of the nephrotoxicity induced by Morning Glory Seed (MGS), a well-known traditional Chinese medicine which was used for the treatment of edema, simple obesity and lung fever. Urinary samples from control and MGS treated rats were analyzed by ultra-performance liquid chromatography/mass spectrometry (UPLC-MS) in positive ionization mode. Blood biochemistry and histopathology were examined to identify specific changes of renal damage. The results affirmatively suggested that ethanol extract of Morning Glory Seed (EMGS), instead of water extract of Morning Glory Seed (WMGS), should be responsible for the nephrotoxicity caused by this herbal medicine. The UPLC-MS analysis revealed that the levels of 8 endogenous metabolites as biomarkers were significantly changed in urine from EMGS treated rats. The underlying regulations of EMGS-perturbed metabolic pathways were discussed according to the identified metabolites. The present study proves the potential of UPLC-MS based metabonomics in mapping metabolic response for toxicology.