藏药材麻花艽中铜锌铁锰含量分析

采用ICP-AES法对青海省内采集的麻花艽中的铜、锌、铁、锰的含量进行了测定。结果表明,麻花艽中四种元素含量丰富,各部位含量差异较大,其中基部茎部含量较高,入药部位根部次之,为以后的开发利用提供了基础数据。     

藏药材麻花秦艽中砷汞铅镉含量分析

对青海省内采集的麻花秦艽中的元素砷、汞、铅、镉的含量进行了分析测定。结果表明,麻花秦艽中四种元素含量较低,并且各部位含量差异较大,其中基部茎叶含量较高,入药部位根部最少,为以后的开发利用提供了基础数据。     

Identification of modification sites on human serum albumin and human hemoglobin adducts with houttuynin using liquid chromatography coupled with mass spectrometry

Houttuynin, a β‐keto aldehyde compound, is the major active ingredient in herba houttuyniae injection. The injection was once used as an anti‐inflammatory drug associated with occasional serious hypersensitivity reactions in the clinic, which were proposed to be related to the formation of protein adducts. N^α‐Boc‐lysine, FEEM and IVTNTT were used as model amino acids or peptides containing one nucleophilic residue to investigate adduct types by liquid chromatography coupled with ion trap mass spectrometry (LC/MSⁿ) and high‐resolution quadrupole time‐of‐flight mass spectrometry (Q‐TOF MS). These adducts were respectively characterized as Schiff bases formed by 1:1 reaction of houttuynin with lysine or N‐terminal residue and pyridinium adducts by 2:1 reaction. LC/MSⁿ analysis of trypsin digests of HSA/Hb incubations with houttuynin revealed that houttuynin‐modified HSA adducts were formed mainly at N‐terminal amino acid and lysine residues, specifically at Lys‐212, Lys‐414 and Lys‐525 for Schiff base adducts, and at Lys‐414 and Lys‐432 for pyridinium adducts, and houttuynin adducted more readily with N‐terminal valine of the α‐ and β‐chains in Hb and lysine amine (Lys‐62) of the β‐chain for Schiff base adducts. The results showed the direct modification of houttuynin to HSA/Hb in vitro, which was speculated to be responsible for the adverse reactions induced by houttuyniae injection. Copyright © 2012 John Wiley & Sons, Ltd.     

Fast profiling of chemical constituents in Yiqing Capsule by ultra-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry

An ultra-performance liquid chromatography/electrospray ionization tandem mass spectrometry (UPLC-ESI-MS(n)) has been developed for structural characterization and identification of multi-constituents in Yiqing Capsule, a well-known combined herbal remedy prepared from the extract mixtures of Rhizoma Coptidis, Radix et Rhizoma Rhei and Radix Scutellariae. The UPLC analysis was performed on an Agilent ZorBax SB-C(18) column (4.6 mm×50 mm, 1.8 μm) and gradient elution of 0.1% formic acid solution and acetonitrile in 16 min. Based on their retention times and mass spectra in comparison with the data from standards or references, a total of 29 compounds including 3 phenolic acids and 4 anthraquinones from Radix et Rhizoma Rhei, 8 alkaloids from Rhizoma Coptidis and 14 flavonoids from Radix Scutellariae were unambiguously identified or tentatively characterized in the complex system. The MS data and fragmentation information of two isomers of feruloylquinic acid were first reported in Radix et Rhizoma Rhei and in Yiqing Capsules. This study is expected to be accepted as an effective and reliable pattern for comprehensive and systematic characterization of this commonly used Chinese herbal preparation.     

Serum metabolite profiling of ST-segment elevation myocardial infarction using liquid chromatography quadrupole time-of-flight mass spectrometry

ST segment elevation myocardial infarction (STEMI) is one of the most common global causes of cardiovascular disease-related death. Several metabolites may change during STEMI. Hence, analysis of metabolites in body fluid may be considered as a rapid and accurate test for initial diagnosis. This study has therefore attempted to determine the variation in metabolites identified in the serum of STEMI patients (n = 20) and 15 controls. Samples collected from the Cardiology Department, Medical Faculty, Ataturk University, were extracted by liquid–liquid extraction and analysed using liquid chromatography quadrupole time-of-flight mass spectrometry. The METLIN database was used for the identification and characterization of metabolites. According to Q-TOF/MS measurements, 231 m/z values, which were significantly different between groups (P < 0.01 and fold analysis >1.5) were detected. Metabolite identification was achieved via the Human Metabolome database. According to the multivariate data analysis, leucine, isoleucine, l -proline, l -alanine, glycine, fumaric acid, citrate, succinate and carnitine levels were decreased, whereas levels of propionic acid, maleic acid, butyric acid, urea, oleic acid, palmitic acid, lysoPC [18:2(9Z)], glycerol, phoshpatidylethanolamine, caffeine and l -lactic acid were increased in STEMI patients compared with controls. In conclusion, malonic acid, maleic acid, fumaric acid and palmitic acid can be used as biomarkers for early risk stratification of patients with STEMI.     

Quality evaluation of Hpericum japomicum by using high‐performance liquid chromatography coupled with photodiode array detector and electrospray ionization tandem mass spectrometry

A high‐performance liquid chromatography coupled with photodiode array detection and electrospray ionization tandem mass spectrometry (HPLC‐PAD‐ESI‐MSⁿ) method was developed to evaluate the quality of Hpericum japomicum through establishing chromatographic fingerprint and simultaneous determination of seven phenolic compounds. The analysis was achieved on an Ultimate XB‐C₁₈ analytical column (250 mm × 4.6 mm i.d., 5 µm) using an aqueous solution of acetic acid (pH 3.8) and methanol as the mobile phase. Ten samples of H. japomicum from various habitats were investigated and the correlation coefficients of similarity were determined from the HPLC fingerprints. By using an online ESI‐MSⁿ, 20 common peaks in chromatographic fingerprints were identified as phenols, including flavones and their glycosides, flavonones and their glucosides, flavanols, xanthones, phloroglucinols, phenyl propanoids and chromones. Based on the above study, seven phenols which are considered to be major constituents in H. japomicum, including 3,4‐dihydroxybenzoic acid (1), taxfolin‐7‐O‐α‐l ‐rhamnoside (7), 7‐dihydroxy‐2‐(1‐methylpropyl)chromone‐8‐β‐d ‐glucoside (8), isoquercitrin (14), quercitrin (16), quercetin‐7‐O‐α‐l‐ rhamnoside (18) and quercetin (19) were quantified by the validated HPLC‐PAD method. This developed method by combination of chromatographic fingerprint and quantification analysis could be applied to control the quality of H. japomicum. Copyright © 2009 John Wiley & Sons, Ltd.     

In vitro metabolism of corydaline in human liver microsomes and hepatocytes using liquid chromatography-ion trap mass spectrometry

Corydaline is a pharmacologically active isoquinoline alkaloid isolated from Corydalis tubers. It exhibits the antiacetylcholinesterase, antiallergic, antinociceptive, and gastric emptying activities. The purposes of this study were to establish in vitro metabolic pathways of corydaline in human liver microsomes and hepatocytes by identification of their metabolites using liquid chromatography-ion trap mass spectrometry. Human liver microsomal incubation of corydaline in the presence of an NADPH-generating system resulted in the formation of nine metabolites, namely, four O-desmethylcorydaline [M1 (yuanhunine), M2 (9-O-desmethylcorydaline), M3 (isocorybulbine), and M4 (corybulbine)], three di-O-desmethylcorydaline [M5 (9,10-di-O-desmethylcorydaline), M6 (2,10-di-O-desmethylcorydaline), and M7 (3,10-di-O-desmethylcorydaline)], M8 (hydroxyyuanhunine), and M9 (hydroxycorydaline). Incubation of corydaline in human hepatocytes produced four metabolites including M1, M5, M6, and M9. O-Demethylation and hydroxylation were the major metabolic pathways for the metabolism of corydaline in human liver microsomes and hepatocytes.     

Simultaneous determination of harpagoside and cinnamic acid in rat plasma by liquid chromatography electrospray ionization mass spectrometry and its application to pharmacokinetic studies

A simple and sensitive method was developed for the simultaneous quantification of harpagoside and cinnamic acid in rat plasma using high-performance liquid chromatography system coupled to a negative ion electrospray mass spectrometric analysis. The plasma sample preparation was a simple deproteinization by the addition of two volumes of acetonitrile. The analytes were separated on an Intersil C8-3 column (2.1 mm i.d.x250 mm, 5 microm) with acetonitrile-5 mm ammonium formate aqueous solution (60:40, v/v) as mobile phase at a flow-rate of 0.2 mL/min. Detection was performed on a quadrupole mass spectrometer equipped with electrospray ionization (ESI) source operated under selected ion monitoring (SIM) mode. [M+HCOO]- at m/z 539 for harpagoside, [M-H]- at m/z 147 for cinnamic acid and [M-H]- at m/z 137 for salylic acid (internal standard) were selected as detecting ions, respectively. The method was validated over the concentration range 7-250 ng/mL for harpagoside and 5-500 ng/mL for cinnamic acid. The lower limits of quantitation for harpagoside and cinnamic acid were 7 and 5 ng/mL, respectively. The intra- and inter-day precisions (RSD%) were within 9.5% and the assay accuracies (RE%) ranged from -5.3 to 3.0% for both analytes. Their average recoveries were greater than 86%. Both analytes were proved to be stable during all sample storage, preparation and analysis procedures. The method was successfully applied to the pharmacokinetic study of harpagoside and cinnamic acid following oral administration of Radix Scrophulariae extract to rats.     

Determination of lignans in flaxseed using liquid chromatography with time-of-flight mass spectrometry

A new method of flaxseed-derived lignan determination was developed using HPLC with high-resolution time-of-flight MS (TOF-MS), optimized, and compared to two existing methods (HPLC/MS/MS and GC/MS). The limits of detection (LODs) for HPLC/TOF-MS (0.002–0.043 pg) were comparable with those of the optimized and improved HPLC/MS/MS (0.001–0.015 pg), whereas the LODs for the optimized GC/MS were higher (0.02–3.0 pg, yet lower than reported before). Using the newly developed detection and separation methods, several key flaxseed sample preparation parameters (including extraction, hydrolysis, and sample purification) were evaluated resulting in the development of efficient protocol for lignan quantification from flaxseed hulls and embryos. The results confirmed the importance of quantification of both aglycones and unhydrolyzed glucosides in order to obtain the total lignan estimates.     

Simultaneous determination of prochlorperazine and its metabolites in human plasma using isocratic liquid chromatography tandem mass spectrometry

Oral prochlorperazine (PCZ), an antiemetic, undergoes extensive first-pass metabolism. The study developed a simultaneous analytical method for PCZ and its major metabolites, prochlorperazine sulfoxide (PCZSO), N-demethylprochlorperazine (NDPCZ) and 7-hydroxyprochlorperazine (PCZOH), in human plasma using an isocratic liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Deproteinized plasma specimens were separated using a 3 μm particle size octadecylsilyl column, and the run time was 10 min. The calibration curves were linear over the concentration ranges of 0.01-40 μg/L for PCZ, NDPCZ and PCZOH, and 0.05-80 μg/L for PCZSO. The intra- and inter-assay precisions and accuracies were within 7.0 and 99-104% and within 9.0 and 99-105%, respectively. The lower limits of quantification in human plasma were 10 ng/L for PCZ, NDPCZ and PCZOH, and 50 ng/L for PCZSO. The validated method was applied to the determination of plasma samples in 37 cancer patients receiving PCZ. Large interindividual variations were observed in plasma concentrations of PCZ, PCZSO, NDPCZ and PCZOH (relative standard deviation, 89.4, 88.7, 86.4 and 78.2%, respectively). In conclusion, this simultaneous LC-MS/MS method with acceptable analytical performance can be helpful for evaluating the pharmacokinetics of PCZ, including the determination of its metabolites in cancer patients and in clinical research.     

Chemical profiling and identification of Radix Cudramiae and their metabolites in rats using an ultra-high-performance liquid chromatography method coupled with time-of-flight tandem mass spectrometry

Radix Cudramiae, known as “Chuan-Po-Shi” in China, is a herbal medicine widely used in the southwest of the country, especially applied by the Miao and Zhuang nationalities for the treatment of liver diseases, such as acute liver injury and liver fibrosis. As a kind of ethnomedicine, the report on its chemical analysis was still blank, which restricted its clinical application. Therefore, this paper aimed to illustrate the chemical characteristics of Radix Cudramiae. A rapid analytical strategy based on ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry was developed to profile the natural small-molecular compounds in Radix Cudramiae, as well as the related prototypes and their metabolites in rats after drug administration. As a result, a total of 74 compounds were detected in the aqueous exact of Radix Cudramiae. In vivo, 45 chemicals including 16 prototypes and 29 metabolites in rat serum, along with 35 chemicals including 17 prototypes and 18 metabolites in rat liver, were screened out and identified. For the first time, the chemical constituents of Radix Cudramiae and their metabolic characteristics were discovered. It was hoped that this work would be beneficial for the safe and effective application of Radix Cudramiae in a clinic.     

Characterization of imazamox degradation by-products by using liquid chromatography mass spectrometry and high-resolution Fourier transform ion cyclotron resonance mass spectrometry

The photodecomposition of imazamox, a herbicide of the imidazolinone family, was investigated in pure water. The main photoproducts from the photolysis were followed over time by liquid chromatography mass spectrometry and structures were proposed from exact mass determinations obtained by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. The method comprised exact mass determination with better than 0.2 ppm mass accuracy and a corresponding structural visualization taking care of respective isotopes with an adapted van Krevelen diagram that enabled a systematic approach to the characterisation of the elementary composition of each photoproduct. By taking advantage of the high resolving power of FT-ICR MS to make precise formula assignments, the derived 2D van Krevelen diagram (O/C; H/C; m/z) enabled one to structurally differentiate the formed photoproducts and to propose a degradation pathway for imazamox. Figure Overview of applied method to analyse the photolysis process of imazamox herbicide     

Rapid quantification of iridoid glycosides analogues in the formulated Chinese medicine Longdan Xiegan Decoction using high-performance liquid chromatography coupled with mass spectrometry [corrected

Longdan Xiegan Decoction (LXD) is a formulated preparation composed of 10 ingredient herbs, with iridoids as the main bioactive components. In this study, a rapid, simple and reliable method of simultaneous determination of four iridoid glycosides in LXD using high-performance liquid chromatography (HPLC) coupled with electrospray ionization mass spectrometry (MS) was first developed and validated. The four iridoid glycosides references were isolated from LXD extract and purified using a preparative HPLC chromatography. The sample preparation for quantification comprised of a simple ultrasonic extraction and the satisfactory chromatographic separation of the four structurally similar iridoid glycosides was effected in less than three minutes on a CAPCELL PAK C(18) MGII column (3 microm, 100 mm x 2.0 mm), using an elution system of 10% methanol and their concentrations in different batches of LXD and ingredient herbs were simultaneously determined by HPLC-MS/MS using a multiple reaction monitoring (MRM) mode. The method was validated with respect to the overall intra- and inter-day variation (RSD less than 8%) and the limits of quantification for the four iridoid glycosides were 35, 20, 37 and 33 ng/mL, respectively.     

Quantitative analysis of acetaminophen and its six metabolites in rat plasma using liquid chromatography/tandem mass spectrometry

Acetaminophen (APAP) is a widely used analgesic and antipyretic drug. It is mainly metabolized by phase 1 and 2 reactions in the liver, and thus it could be involved in many drug–drug interactions. Therefore, the study of APAP metabolism is important in toxicological and pharmacokinetic studies. The objective of this study was to develop a rapid and sensitive method for the determination of APAP and its six metabolites in rat plasma for the pharmacokinetic studies. APAP and its metabolites were separated through a Capcell Pak MGII C₁₈ column and quantitated with a 16 min run in a triple‐quadruple mass spectrometer. The mobile phases were composed of 0.1% formic acid in either 95% water or 95% acetonitrile and analysis was performed twice in positive and negative modes. Validations such as accuracy, precision, recovery, matrix effect and stability were found to be within acceptance criteria of validation guidelines, indicating that the assay was applicable to the determination of the plasma concentrations of drug and its six metabolites. In conclusion, we developed an LC‐MS/MS method for the quantitative analysis of APAP and its six metabolites in rat plasma, and this method appears to be useful for pharmacokinetic/toxicokinetic studies of APAP and its metabolites in rats. Copyright © 2012 John Wiley & Sons, Ltd.     

Determination of salbutamol in human plasma and urine using liquid chromatography coupled to tandem mass spectrometry and its pharmacokinetic study

A sensitive and selective liquid chromatography coupled to tandem mass spectrometry (LC‐MS/MS) was developed and validated for the determination of salbutamol in human plasma and urine, and successfully applied to the pharmacokinetic study of salbutamol in Chinese healthy volunteers after inhalation of salbutamol sulfate aerosol. Salbutamol and the internal standard (IS) acetaminophen in plasma and urine were extracted with ethyl acetate, separated on a C₁₈ reversed‐phase column, eluted with mobile phase of acetonitrile–ammonium acetate (5 m m ; 30:70, v/v), ionized by positive ion pneumatically assisted electrospray and detected in the multi‐reaction monitoring mode using precursor → product ions of m/z 240.2 → 148.1 for salbutamol and 152 → 110 for the IS. The lower limits of quantitation of salbutamol in human plasma and urine by this method were 0.02 and 1 ng/mL, respectively. The specificity, matrix effect, recovery, sensitivity, linearity, accuracy, precision and several stabilities were validated for salbutamol in human plasma and urine. In conclusion, the validation results showed that this method is robust, specific and sensitive, and can successfully fulfill the requirement of clinical pharmacokinetic study of salbutamol in healthy Chinese volunteers. Copyright © 2011 John Wiley & Sons, Ltd.     

Quantitative analysis of docetaxel in human plasma using liquid chromatography coupled with tandem mass spectrometry

An assay for the quantitative determination of docetaxel in human plasma is described. Docetaxel was extracted from the matrix using liquid-liquid extraction with ter-butylmethylether, followed by high-performance liquid chromatographic analysis using an alkaline eluent. Paclitaxel was used as internal standard. Positive ionization electrospray tandem mass spectrometry was performed for selective and sensitive detection. The method was validated according to the FDA guidelines on bioanalytical method validation. The validated range for docetaxel was from 0.25--1000 ng/mL using 200 microL plasma aliquots. The method requires only a limited volume (200 microL) of human plasma and the method can be applied in studies requiring a low lower limit of quantitation of 0.25 ng/mL. The assay was applied successfully in several clinical and pharmacological studies with docetaxel.     

Metabolomics study of cured tobacco using liquid chromatography with mass spectrometry: Method development and its application in investigating the chemical differences of tobacco from three growing regions

Cured tobacco is an important plant material. Component studies are a big challenge for its significantly diverse chemical properties and vastly different concentrations. In this work, liquid chromatography with quadrupole time‐of‐flight mass spectrometry was used to perform a metabolomics study of cured tobacco owing to its efficient separation and detection of semipolar metabolites. A solvent of methanol/water (8:2, v/v) and 30 min of ultrasound time were found to be optimal to perform extraction. 95, 92, and 93% of metabolite features had within 20% of coefficient of variation for repeatability, intraday and interday precision analysis, respectively, indicating a good stability of the method developed. 113 metabolites were identified in cured tobacco based on accurate mass, retention time, and MS/MS fragments. The developed method was applied to a metabolomics study of cured tobacco from three growing regions. Forty three metabolites were found to be contributed to the classification. It is shown that the developed method can be applied to metabolomics analysis of plant materials.     

Studies on lignan constituents from Schisandra chinensis (Turcz.) Baill. fruits using high-performance liquid chromatography/electrospray ionization multiple-stage tandem mass spectrometry

A reversed-phase high-performance liquid chromatography-diode array detector-electrospray ionization multiple-stage tandem mass spectrometry (RP-HPLC-DAD-ESI-MS(n)) method has been developed for the detection and analysis of lignan constituents in the methanol extract from the fruits of Schisandra chinensis (Turcz.) Baill. RP-HPLC-DAD-ESI-MS(n) and electrospray ionization Fourier transform ion cyclotron resonance multiple-stage tandem mass spectrometry (ESI-FT-ICR-MS(n)) have been applied to investigate the characteristic product ions of four lignan reference compounds. Then, the logical fragmentation pathways of the lignans have been proposed. By comparing the retention time (t(R)) of HPLC, the ESI-MS(n) data and the structures of analyzed compounds with the data of reference compounds and in the literature, 11 peaks in HPLC have been unambiguously identified and another 5 peaks have been tentatively identified or deduced. Also, in the present paper, the extracted ion chromatograms (EIC) have been used to analyze the lignan isomers. The experimental results demonstrate that RP-HPLC-DAD-ESI-MS(n) is a specific and useful method for the identification of the lignan constituents and their isomers.     

Determination of azasetron hydrochloride in rabbit plasma by liquid chromatography tandem mass spectrometry and its application

A sensitive and selective liquid chromatography tandem mass spectrometry method for determination of azasetron hydrochloride in rabbit plasma was developed. After addition of doxapram hydrochloride as internal standard (IS), protein precipitation by 10% trichloroacetic acid was used as sample preparation. Chromatographic separation was achieved on a Zorbax SB-C(18) (2.1 × 50 mm, 3.5 μm) column with acetonitrile-water as mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reaction monitoring mode was used to quantification using target fragment ions m/z 349.9 → 223.5 for azasetron hydrochloride and m/z 378.9 → 291.8 for the IS. Calibration plots were linear over the range of 6-1000 ng/mL for azasetron hydrochloride in plasma. The lower limit of quantitation for azasetron hydrochloride was 6 ng/mL. The mean recovery of azasetron hydrochloride from plasma was in the range 85.6-92.7%. The RSDs of intra-day and inter-day precision were both less than 12%. This method is simple and sensitive enough to be used in pharmacokinetic research for determination of azasetron hydrochloride in rabbit plasma.     

Determination of nonsteroidal antiinflammatory drugs in water samples using liquid chromatography coupled with diode-array detector and mass spectrometry

An analytical method for the determination of trace levels of six different nonsteroidal antiinflammatory drugs (NSAIDs) in water samples has been developed and validated. Environmentally relevant pharmaceuticals were chosen according to human consumption in Poland. Final analysis of the target compounds was performed by RP LC-diode-array detection-MS, whereas sample preparation included an SPE step. For this SPE step, a number of packing materials, such as LiChrolut RP-18, calixarene, Strata-X, BAKERBOND Narc-2, BAKERBOND Polar Plus, BAKERBOND styrene divinylbenzene-1, and Discovery DSC-18, were used, and their respective advantages and disadvantages in this study were discussed. The RP-18 phase was found to be the most retentive for all analytes. The detection limits for compounds in surface waters were varied from 0.005 for diflunisal to 0.095 microg/L for ibuprofen. The average recoveries of NSAIDs from the surface water samples ranged from 80 up to 103%. RSD value is relatively low (from 4% for fenoprofen up to 8% for ibuprofen). The performance of the method was tested with several environmental water samples.