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1.
LC‐MS/MS method for the determination of agomelatine in human plasma and its application to a pharmacokinetic study 下载免费PDF全文
Xiaolin Wang Dan Zhang Man Liu Hongna Zhao Aihua Du Lingjie Meng Huichen Liu 《Biomedical chromatography : BMC》2014,28(2):218-222
A sensitive and selective LC‐MS/MS method for the determination of agomelatine in human plasma was developed and validated. After simple liquid–liquid extraction, the analytes were separated on a Zorbax SB‐C18 column (150 × 2.1 mm i.d., 5 µm) with an isocratic mobile phase consisting of 5 mm ammonium acetate solution (containing 0.1% formic acid) and methanol (30:70, v/v) at a flow‐rate of 0.3 mL/min. The MS acquisition was performed in multiple reaction monitoring mode with a positive electrospray ionization source. The mass transitions monitored were m/z 244.1 → 185.3 and m/z 285.2 → 193.2 for agomelatine and internal standard, respectively. The methods were validated for selectivity, carry‐over, matrix effects, calibration curves, accuracy and precision, extraction recoveries, dilution integrity and stability. The validated method was successfully applied to a pharmacokinetic study of agomelatine in Chinese volunteers following a single oral dose of 25 mg agomelatine tablet. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
2.
《Biomedical chromatography : BMC》2018,32(10)
In this study the comparison of human liver microsomes in in vitro incubation as well as ZnO‐ and TiO2‐assisted photocatalytic degradation of clozapine as a mimicking method of phase I metabolism transformation was performed. Based on reversed‐phase UHPLC separation and high‐resolution MS/MS data, eight transformation products were identified and seven of them were found to be hepatic metabolites of the parent compound. The multivariate chemometric comparison of the obtained results shows ZnO‐assisted photocatalysis to be a more suitable approach to phase I metabolism simulation. The photocatalytic experiments demonstrated that the disappearance of clozapine followed pseudo‐zero order kinetics. 相似文献
3.
Jiu-ming Li Jian-ping Yong Feng-lan Huang Shu-zhen Bai 《Chemistry of Natural Compounds》2012,48(1):103-105
The sex pheromone of Grapholitha molesta, (Z/E)-8-dodecylen-1-ol acetate, was easily synthesized in an overall yield of 41.5% with 1,8-octanediol as starting material via
mono-esterification, PCC oxidation, and Witting reactions. The Z/E ratio is 83:17. Configuration transformation of Z/E 83:17 compound with sodium nitrite and nitric acid resulted in the production of a compound with Z/E 24:76. The products were confirmed by IR, 1H NMR, and MS spectral data. 相似文献
4.
Fiori J Gotti R Albini A Cavrini V 《Rapid communications in mass spectrometry : RCM》2008,22(17):2698-2706
The photostability of guaiazulene (1,4-dimethyl-7-isopropylazulene; GA), a natural azulenic compound used in cosmetic and health-care products, as well as in pharmaceutical preparations, was investigated in solution (methanol, ethanol, acetonitrile), by different techniques: gas chromatography/mass spectrometry (GC/MS) and high-performance liquid chromatography combined with atmospheric pressure chemical ionization mass spectrometry and UV detection (LC/APCI-MS and HPLC/UV). A solar simulator (xenon-arc lamp) was used as UV-A radiation source. The study involved: monitoring compound decomposition, identifying products of photodegradation (PPs), assessing the role of oxygen and evaluating the kinetics of the process. Minor PPs are volatile compounds and were characterized by GC/MS, while oligomeric polyoxygenated compounds, tentatively characterized on the basis of MS and MS/MS spectra, were found to be the main photoproducts. The photodegradation was found to be enhanced by the presence of oxygen; nevertheless, determination of the singlet oxygen quantum yield for GA gave a lower value than that for the reference standard Rose Bengal. The obtained results and the developed stability-indicating methods (GC/MS and LC/MS) are of interest for stability studies and/or quality control purposes of GA as raw material or cosmetic products. 相似文献
5.
Identification of transformation products from β‐blocking agents formed in wetland microcosms using LC‐Q‐ToF 下载免费PDF全文
Alfred Svan Mikael Hedeland Torbjörn Arvidsson Justin T. Jasper David L. Sedlak Curt E. Pettersson 《Journal of mass spectrometry : JMS》2016,51(3):207-218
Identification of degradation products from trace organic compounds, which may retain the biological activity of the parent compound, is an important step in understanding the long‐term effects of these compounds on the environment. Constructed wetlands have been successfully utilized to remove contaminants from wastewater effluent, including pharmacologically active compounds. However, relatively little is known about the transformation products formed during wetland treatment. In this study, three different wetland microcosm treatments were used to determine the biotransformation products of the β‐adrenoreceptor antagonists atenolol, metoprolol and propranolol. LC/ESI‐Q‐ToF run in the MSE and MS/MS modes was used to identify and characterize the degradation products through the accurate masses of precursor and product ions. The results were compared with those of a reference standard when available. Several compounds not previously described as biotransformation products produced in wetlands were identified, including propranolol‐O‐sulfate, 1‐naphthol and the human metabolite N‐deaminated metoprolol. Transformation pathways were significantly affected by microcosm conditions and differed between compounds, despite the compounds' structural similarities. Altogether, a diverse range of transformation products in wetland microcosms were identified and elucidated using high resolving MS. This work shows that transformation products are not always easily predicted, nor formed via the same pathways even for structurally similar compounds. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
6.
Mathilde Triquigneaux Béatrice Tuccio Robert Lauricella Laurence Charles 《Journal of the American Society for Mass Spectrometry》2009,20(11):2013-2020
Mass spectrometry (MS) was used in conjunction with electron paramagnetic resonance (EPR) to characterize products arising
from reactions between reduced glutathione (GSH) and 2-methyl 2-nitroso propane (MNP) in an oxidative medium, to evaluate
the reactivity of this tripeptide as a nucleophile toward a nitroso compound. Depending on the experimental conditions, different
radical species could be detected by EPR, which allowed some structural assumptions. These samples were then submitted to
electrospray ionization, in both positive and negative ion modes, for structural elucidation in tandem mass spectrometry.
Although the primary nitroxide products could not be detected in MS, structurally related compounds such as hydroxylamine
and O-methyl hydroxylamine could be fully characterized. In the absence of light, a S-adduct was formed via a Forrester-Hepburn reaction, that is, a nucleophile addition of MNP onto the thiol function in reduced
glutathione to yield a hydroxylamine intermediate, further oxidized into nitroxide. In contrast, irradiating the reaction
medium with visible light could allow an inverted spin trapping reaction to take place, involving the oxidation of both MNP
and GSH before the nucleophilic addition of the sulfenic acid function onto the nitrogen of MNP, yielding a so-called O-adduct. It was also found that dilution of the reaction medium with methanol for the purpose of electrospray ionization could
allow nitroxides to be indirectly observed either as hydroxylamine or O-methyl hydroxylamine species. 相似文献
7.
Christoph Bttcher Edda von Roepenack‐Lahaye Jürgen Schmidt Stephan Clemens Dierk Scheel 《Journal of mass spectrometry : JMS》2009,44(4):466-476
Total phenolic choline ester fractions prepared from seeds of Arabidopsis thaliana and Brassica napus were analyzed by capillary LC/ESI‐QTOF‐MS and direct infusion ESI‐FTICR‐MS. In addition to the dominating sinapoylcholine, 30 phenolic choline esters could be identified based on accurate mass measurements, interpretation of collision‐induced dissociation (CID) mass spectra, and synthesis of selected representatives. The compounds identified so far include substituted hydroxycinnamoyl‐ and hydroxybenzoylcholines, respective monohexosides as well as oxidative coupling products of phenolic choline esters and monolignols. Phenolic choline esters are well separable by reversed‐phase liquid chromatography and sensitively detectable using electrospray ionization mass spectrometry in positive ion mode. CID mass spectra obtained from molecular ions facilitate the characterization of both the type and substitution pattern of such compounds. Therefore, LC/ESI‐MS/MS represents a valuable tool for comprehensive qualitative and quantitative analysis of this compound class. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
8.
Zhang YP Shi SY Xiong X Chen XQ Peng MJ 《Analytical and bioanalytical chemistry》2012,402(9):2965-2976
Traditional activity-guided fractionation of natural products is a time-consuming, labor intensive, and expensive strategy,
which cannot compete with high-throughput and rapid screening of natural products. Therefore, more efficient approaches are
necessary for searching active compounds from natural products. Three main methods based on high-performance liquid chromatography
(HPLC) analysis combined with 2,2′-diphenyl-1-picrylhydrazyl (DPPH) assay, DPPH spiking HPLC analysis, on-line post-column
HPLC-DPPH analysis, and HPLC-based DPPH activity profiling, were then developed for the rapid screening of antioxidants from
complex mixtures. In the present study, a comparative study of these three methods has been conducted to identify antioxidants
from an ethyl acetate fraction of Pueraria lobata flowers. The parameters in HPLC analysis and DPPH assay were optimized. The results indicated that all three methods could
achieve similar information with regard to antioxidants, without the need for preparative isolation techniques. However, there
were differences in instrumental set-up, sensitivity, and efficiency. DPPH spiking HPLC analysis seemed to be more sensitive
and effective with simpler instrumental set-up and easier operation, which could also detect the total antioxidant capacity
of color complexes. Eighteen antioxidants were tentatively screened and identified from P. lobata flowers by DPPH spiking HPLC-MS/MS. Among them, ten compounds including one new compound were first isolated from P. lobata flowers, and the DPPH radical scavenging activity of the new compound was reported for the first time. 相似文献
9.
报道了9-(β-D-2'-脱氧核糖基)-6-甲基嘌呤合成的新方法. 以肌苷1为原料, 经酯化、氯化、氨解得6-氯嘌呤核苷(4), 再经过羟基保护、6-位甲基化反应及脱保护反应得到关键中间体6-甲基嘌呤核苷7, 用1,3-二氯-1,1,3,3-四异丙基二硅氧烷保护7核糖上的3,5-二羟基, 2-羟基与苯氧基硫代甲酰氯反应后得到9, 然后与氢化三正丁基锡[HSn(Bu-n)3]还原脱氧, 最后脱保护得到目标化合物11. 产物结构经MS, 1H NMR, 元素分析等鉴定. 相似文献
10.
Tamar Shamai Yamin Hagit Prihed Moran Madmon Merav Blanca Avi Weissberg 《Journal of mass spectrometry : JMS》2020,55(10)
V‐nerve agents present information‐poor spectra, both in GC‐EI‐MS and LC‐ESI‐MS/MS, with dominant fragments/product ions corresponding to the amine‐containing residue. Hence, derivatives/isomers with the same amine residue exhibit similar mass spectral patterns, leading to ambiguity in the phosphonate structure. We present a simple approach for their structural elucidation based on two complementary experiments: ESI‐MS/MS of the original compound, which provides information about the amine moiety, and ESI‐MS/MS of the phosphonic acid hydrolysis products generated by N‐iodosuccinimide, which provides ions' characteristic of the phosphonate structure. This approach enables the structural elucidation of the original V‐agents with a higher degree of certainty. 相似文献
11.
Andreas Schürmann Veronika Dvorak Claudio Crüzer Patrick Butcher Anton Kaufmann 《Rapid communications in mass spectrometry : RCM》2009,23(8):1196-1200
In pesticide residue analysis using liquid chromatography/tandem mass spectrometry (LC/MS/MS) the confirmation of a sebuthylazine finding in a tarragon (Artemisia dranunculus) sample was demonstrated to be false positive. A coeluting interfering matrix compound produced product ions in MS/MS analysis, perfectly corresponding to the multiple reaction monitoring (MRM) of two sebuthylazine transitions. Using the EU directive 2002/657/EC which regulates the confirmation of suspected positive findings would have resulted in a false‐positive finding. A third LC/MS/MS transition with a deviant ion ratio and a gas chromatography (GC)/MS/MS analysis revealed the false‐positive results. With optimized high resolving ultra‐performance liquid chromatography (UPLC) conditions it was possible to separate spiked sebuthylazine from the interfering matrix compound. Using its exact mass and isotope ratios from LC/time‐of‐flight (TOF) MS measurements, the compound was identified as nepellitorine, a – not surprising – endogenous alkamide in tarragon (Arthemisia dranunculus). False‐positive results, especially in heavy matrix samples such as herbs, can be dealt with by further confirmatory analysis, e.g. a third transition, GC analysis if possible or more advantageous by an orthogonal criterion like exact mass. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
12.
Bo Zhong Yaxin Li Nethrie Idippily Aaron Petty Bin Su Bingcheng Wang 《Biomedical chromatography : BMC》2019,33(4)
Compound 27 {1, 12‐bis[4‐(4‐amino‐6,7‐dimethoxyquinazolin‐2‐yl)piperazin‐1‐yl]dodecane‐1,12‐dione} is a novel small molecule agonist of EphA2 receptor tyrosine kinase. It showed much improved activity for the activation of EphA2 receptor compared with the parental compound doxazosin. To support further pharmacological and toxicological studies of the compound, a method using liquid chromatography and electrospray ionization tandem mass spectrometry (LC–MS/MS) has been developed for the quantification of this compound. Liquid–liquid extraction was used to extract the compound from mouse plasma and brain tissue homogenate. Reverse‐phase chromatography with gradient elution was performed to separate compound 27 from the endogenous molecules in the matrix, followed by MS detection using positive ion multiple reaction monitoring mode. Multiple reaction monitoring transitions m/z 387.3 → 290.1 and m/z 384.1 → 247.1 were selected for monitoring compound 27 and internal standard prazosin, respectively. The linear calibration range was 2–200 ng/mL with the intra‐ and inter‐day precision and accuracy within the acceptable range. This method was successfully applied to the quantitative analysis of compound 27 in mouse plasma and brain tissue with different drug administration routes. 相似文献
13.
Silvan Eichenberger Michaël Méret Stefan Bienz Laurent Bigler 《Journal of mass spectrometry : JMS》2010,45(2):190-197
N‐Hydroxylated polyamine derivatives were found to decompose during the ionization process of liquid chromatography‐atmospheric pressure chemical ionization‐mass spectrometry (LC‐APCI‐MS) experiments. The phenomenon was studied with a model compound, a synthetic N‐hydroxylated tetraamine derivative. It was found that reduction, oxidation and water elimination occurred during APCI to generate the corresponding amine, N‐oxide, and imine. The investigation further revealed that decomposition of hydroxylamines during APCI depends upon the concentration of the analyte and on the acidity of the solution introduced into the ionization source. The pH‐dependence of decomposition was utilized for the development of an MS method that allows for the unambiguous identification of N? OH functionalities. This method was applied for the study of natural products including polyamine toxins from the venom of the spider Agelenopsis aperta and mayfoline, a cyclic polyamine derivative of the shrub Maytenus buxifolia. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
14.
Vahideh Mahdavi Fatemeh Ghorbani-Paji Mohammad Kazem Ramezani 《International journal of environmental analytical chemistry》2019,99(10):968-976
Currently, there is growing interest in the degradation pathways of organic contaminants such as pesticides. In the case of pesticides, the determination of metabolites in agricultural products and environment is necessary as some of them could present similar toxicity to or even higher toxicity than the parent compound. The development of analytical methodology for the identification and quantification of carbendazim fungicide and its metabolites in cucumber was studied. Cucumber (cucumis sativus) is a global food in terms of economic importance and nutritional quality. Careful optimisation of the liquid chromatography–mass spectrometry (LC-MS)/MS parameters was achieved in order to attain a fast separation with the best sensitivity. The detection was carried out on an Ion-Trap tandem mass spectrometer (MS/MS) by electrospray ionisation in positive ion mode (ESI+) with multiple reaction monitoring (MRM). 相似文献
15.
Anna Martínez‐Villalba Oscar Núñez Encarnación Moyano M. Teresa Galceran 《Electrophoresis》2013,34(6):870-876
Veterinary medicines are widely administered to farm animals since they keep animals healthy at overcrowded conditions. Nevertheless the continuous administration of medicines to farm animals can frequently lead to the presence of residues of veterinary drugs in consumption products. Amprolium is a quaternary ammonium compound used in the treatment of coccidiosis. In this paper, a method based on CZE to analyze residues of amprolium in eggs was developed and validated for the first time. Parameters such as electrolyte type, concentration, and pH were optimized. In order to improve sensitivity, field‐amplified sample injection (FASI) was used for in‐line preconcentration after a quick and simple sample treatment based on SPE (Envi‐Carb). During method‐validation studies using egg samples, a matrix interference was found at the migration time of amprolium. This compound was identified as thiamine and confirmed by MSn experiments using CEcoupled to MS (CE‐MS) with an ion‐trap mass analyzer. CZE conditions were reoptimized to separate thiamine from amprolium allowing the quantification of amprolium in eggs at concentrations down to 75 μg/kg, which are far below the MRL‐legislated values. 相似文献
16.
Wenna Zhou Zhenzhen Yuan Gang Li Jian Ouyang Yourui Suo 《Natural product research》2018,32(8):892-897
In this study, a valid method was established for the isolation and purification of flavone glycosides from Hippophae rhamnoides L. seed residues using high-speed counter-current chromatography in one step, with a solvent system of ethyl acetate-methanol-n-butyl alcohol-water (9:1:0.5:9, v/v/v/v). A total of 28.8 mg compound I and 57.3 mg compound II were obtained from 200 mg of flavone H-glycosides rich extract, with purities of 98.3 and 96.4%, respectively. The structures of two compounds were identified by MS and NMR. 3-O-β-D-Sophorosylkaempferol-7-O-{3-O-[2(E)-2,6-dimethyl-6-hydroxyocta-2,7-dienoyl]}-α-L-rhamnoside is compound I and compound II named hippophanone is a new compound were identified by MS and NMR. The method was efficient and convenient, which could be used for the preparative separation of flavone glycosides from H. rhamnoides L. seed residues. 相似文献
17.
《Biomedical chromatography : BMC》2018,32(9)
A rapid, sensitive and reproducible LC–MS/MS method was developed and validated to determine iguratimod in human plasma. Sample preparation was achieved by protein precipitation with acetonitrile. Chromatographic separation was operated on an Ultimate® XB‐C18 column (2.1 × 50 mm, 3.5 μm, Welch) with a flow rate of 0.400 mL/min, using a gradient elution with acetonitrile and water which contained 2 mm ammonium acetate and 0.1% formic acid as the mobile phase. The detection was performed on a Triple Quad™ 5500 mass spectrometer coupled with an electrospray ionization interface under positive‐ion multiple reaction monitoring mode with the transition ion pairs of m/z 375.2 → 347.1 for iguratimod and m/z 244.3 → 185.0 for agomelatine (the internal standard), respectively. The method was linear over the range of 5.00–1500 ng/mL with correlation coefficients ≥0.9978. The accuracy and precision of intra‐ and inter‐day, dilution accuracy, recovery and stability of the method were all within the acceptable limits and no matrix effect or carryover was observed. As a result, the main pharmacokinetic parameters of iguratimod were as follows: Cmax, 1074 ± 373 ng/mL; AUC0–72, 13591 ± 4557 ng h/mL; AUC0–∞, 13,712 ± 4613 ng h/mL; Tmax, 3.29 ± 1.23 h; and t1/2, 8.89 ± 1.23 h. 相似文献
18.
A method based on pressurized liquid extraction and LC‐MS/MS has been developed for determining nine benzoylureas (BUs) in fruit, vegetable, cereals, and animal products. Samples (5 g) were homogenized with diatomaceous earth and extracted in a 22 mL cell with 22 mL of ethyl acetate at 80°C and 1500 psi. After solvent concentration and exchange to methanol, BUs were analyzed by LC‐MS/MS using an IT mass analyzer, which achieved several transitions of precursor ions that increase selectivity providing identification. LOQs were between 0.002 and 0.01 mg/kg, which are equal or lower than maximum residue limits established by the Codex Alimentarius. Excellent linearity was achieved over a range of concentrations from 0.01 to 1 mg/kg with correlation coefficients 0.995–0.999 (n=7). Validation of the total method was performed by analyzing in quintuplicate seven different commodities (milk, eggs, meat, rice, lettuce, avocado, and lemon) at three concentration levels (0.01, 0.1, and 1 mg/kg). The recoveries ranged from 58 to 97% and the RSDs from 5 to 19% depending on the compound and the commodity. The combination of pressurized liquid extraction with LC‐MS/MS provides a sensitive and selective method for the determination of BUs in food. 相似文献
19.
Herba Dendrobii has been documented in the Compendium of Materia Medica, with special efficacy in nourishing Yin and treating diabetes. However, the chemical profile of Dendrobium chrysanthum Lindl. has not been reported yet. The compositions were analysed with UPLC/Q-TOF-MS/MS. 53 compounds were tentatively characterised, and 14 compounds might be new compounds. Some novel lactones of poly-phenylpropanoids were firstly detected, and di-p-hydroxyphenylpropionic acidic p-coumaric acid lactone, a new compound of the first example, was obtained and identified. UPLC/Q-TOF-MS/MS was a feasible and efficient method to discover the unique compounds in complex matrices of D. chrysanthum. 相似文献
20.
Pavel Hradil Lubomír Kvapil Jan Hlav
Tom Weidlich Antonín Ly
ka Karel Lemr 《Journal of heterocyclic chemistry》2000,37(4):831-837
The cyclization of phenacyl anthranilate has been studied with the aim to develop the synthesis of 2‐(2′‐aminophenyl)‐4‐phenyloxazole. However, a different course of the reaction than expected was observed. 2‐Phenyl‐2‐hydroxymethyl‐4‐oxo‐1,2,3,4‐tetrahydroquinazoline ( 3a ) was formed by the reaction of phenacyl anthranilate ( 2 ) with ammonium acetate under various conditions. 3‐Hydroxy‐2‐phenyl‐4(1H)‐quinolinone ( 4 ) arose by heating compound 3a in acetic acid. The same compound was obtained by melting compound 3a , but the yield was lower. Different types of products resulted in the reaction of compound 3a with acetic anhydride. Under mild conditions acetylated products 2‐acetoxymethyl‐2‐phenyl‐4‐oxo‐1,2,3,4‐tetrahydroquinazoline ( 7a ) and 2‐acetoxymethyl‐3‐acetyl‐2‐phenyl‐4‐oxo‐1,2,3,4‐tetrahydroquinazoline ( 8 ) were prepared. If the reaction was carried out under reflux of the reaction mixture, molecular rearrangement took place to give cis and trans 2‐methyl‐4‐oxo‐3‐(1‐phenyl‐2‐acetoxy)vinyl‐3,4‐dihydroquinazolines ( 9a and 9b ). All prepared compounds have been characterised by their 1H, 13C and 15N NMR spectra, IR spectra and MS. 相似文献