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91.
《Biomedical chromatography : BMC》2018,32(9)
A simple and reliable LC–MS/MS method was established for simultaneous determination of 12 components from acetylkitasamycin and kitasamycin in swine plasma. The analytes were separated on a Shim‐pack VP‐ODS column with a 25 min gradient elution using 5 mmol/L ammonium acetate and acetonitrile as the mobile phase at a flow rate of 0.2 mL/min. Identification and quantification were accomplished by electrospray ionization) in positive mode using multiple reaction monitoring. The limits of quantitation of acetylkitasamycin A1A3, A13 and kitasamycin A3, A13 were 3 μg/L, and that of the other eight components was 5 μg/L. The mean recoveries of kitasamycin and acetylkitasamycin ranged from 85.3 to 103.5%. The developed method was successfully applied to a pharmacokinetic study in swine after intravenous (i.v.) and oral (p.o.) administration of acetylkitasamycin. The result showed that the plasma concentrations of acetylkitsamycin components were much higher than that of kitasamycin in swine after i.v. and p.o., in which acetylkitsamycin A4A5 was the highest component at each time point. 相似文献
92.
《Biomedical chromatography : BMC》2017,31(10)
A rapid and sensitive liquid chromatography with tandem mass spectrometry (LC‐MS/MS) method was developed and validated for the simultaneous determination of luteolin, luteolin‐7‐O ‐β ‐D‐glucopyranoside, physalin A, physalin D and physalin L in rat plasma. Scutellarein and dexamethasone were used as the internal standards (IS). Plasma samples were prepared by liquid‐liquid extraction with ethyl acetate. The five constituents were separated on an Acquity UPLC BEH C18 column (100 mm × 2.1 mm, 1.7 μm). A gradient elution procedure was used with acetonitrile (A)‐0.1% aqueous formic acid (B). Mass spectrometric detection was performed in negative ion multiple reaction monitoring mode with an electrospray ionization (ESI) source. This method showed good linearity (r 2 > 0.997) over a concentration range of 2.0–500 ng/mL with a lower limit of quantification of 2.0 ng/mL for all five compounds. The inter‐ and intra‐day accuracy ranged from 91.7 to 104%, and precisions (RSD) were <6.46% for all analytes. The extraction recoveries of all analytes were >85%. This validated method was successfully applied for the first time to the pharmacokinetic study of five ingredients after oral administration of 70% ethanol extract of Chinese lantern in rats. 相似文献
93.
《Biomedical chromatography : BMC》2017,31(6)
We developed and validated a high‐resolution liquid chromatography mass spectrometry method for the quantification of furosemide in camel plasma which was used for a pharmacokinetic study in camels. Plasma samples were extracted by supported liquid extraction and furosemide and internal standard (furosemide‐D5) were separated on a an Agilent Zorbax XDB C18 column (50 × 2.1 mm i.d., 3.5 μm). Data was acquired in full‐scan mode over a mass range of 200–400 Da in negative electrospray mode at a resolution of 70,000. Linear calibration curves were obtained over the concentration ranges of 1.0–10,000 ng/mL. The validated method was then successfully applied in evaluating the pharmacokinetics and metabolites of furosemide in six camels (Camelus dromedarus ) and we were able to advice on a withdrawal time of furosemide treatment before racing. 相似文献
94.
《Biomedical chromatography : BMC》2017,31(5)
The chromatographic hydrophobicity index (CHI) is an HPLC‐based parameter that provides reliable guidance in optimization of pharmacological efficiency and adsorption, distribution, metabolism and exertion (ADME) profile of drug candidates. In the present work, classical and three‐dimensional quantitative structure–property relationship (QSPR) models were developed for prediction of CHI values of some 4‐hydroxycoumarin analogs on immobilized artificial membrane column. Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) as 3D–QSPR methods were performed to gain insight into the key structural factors affecting on the chromatographic hydrophobicity of interested chemicals. The calculated parameters of Q 2, R 2 and standard error were 0.545, 0.996 and 0.773 for CoMFA model and 0.815, 0.986 and 1.44 for CoMSIA model, respectively. The contour maps for steric fields of the CoMFA model illustrate that the hydrophobicity of chemicals will be higher when the positions of R6, R7 and R8 in the 4‐hydroxycuomarin ring are substituted by alkyl groups. Moreover, by the analysis of the plots of electrostatic fields, it was concluded that the CHI value greatly increases if one hydrogen on coumarin ring is substituted by the F, Cl, Br, OH or OCH3 group. 相似文献
95.
《Biomedical chromatography : BMC》2017,31(10)
Propafenone is a potent antiarrhythmic agent; clinically propafenone has been used for a number of cardiac arrhythmias because it possesses multiple modes of action, via beta adrenergic receptor blockade and calcium antagonistic activity. Propafenone (PPF) exhibits extensive saturable presystemic biotransformation (first‐pass effect) resulting in two active metabolites: 5‐hydroxypropafenone (5‐OH PPF) formed by CYP2D6 and N‐ depropylpropafenone (NDP) formed by both CYP3A4 and CYP1A2 enzymes. A specific and sensitive LC–MS/MS method was developed and validated for quantitation of PPF, 5‐OH PPF and NDP using turboion spray in a positive ion mode. A solid‐phase extraction was employed for the extraction from human plasma. Chromatographic separation of analytes was achieved using an ACE‐5 C8 (50 × 4.6 mm) column with a gradient mobile phase comprising ammonium acetate containing 0.01% TFA in purified water and acetonitrile. The retention times achieved were 1.36, 1.23, 1.24 min and 1.34 min for PPF, 5‐OH PPF, NDP and IS (carbamazepine), respectively. Quantitation was performed by monitoring multiple reaction monitoring transition pairs of m /z 342.30 to m /z 116.20, m /z 358.30 to m /z 116.20, m /z 300.30 to m /z 74.20 and m /z 237.20 to m /z 194.10, respectively. The developed method was validated for various parameters. The calibration curves of PPF and 5‐OH PPF showed linearity from 1 to 500 ng/mL, with a lower limit of quantitation of 1.0 ng/mL and for NDP linearity from 0.1 to 25 ng/mL with a lower limit of quantitation of 0.1 ng/mL. The bias and precision for intra‐ and‐inter batch assays were <10 and 5%, respectively. The developed assay was used to evaluate pharmacokinetic properties of propafenone and its major metabolites in healthy human subjects. 相似文献
96.
In this paper, plasma concentration, plasma protein binding rate, body distribution, and excretion of both oral and intravenous administration of rats were determined by high performance liquid chromatography (HPLC) combining with UV detector. The blood drug concentration of oral and intravenous administration was summarized. The bioavailability of T1/2 was approximately 0.75?hr. At the meanwhile, the bioavailability was about 18.84?±?2.21%. The plasma protein binding rate of 1-methyl hydantoin was about 24.36?±?0.93%, belonging to low protein binding drug. The result shows that 1-methyl hydantoin can be rapidly distributed in various organs and tissues and quickly eliminated within 6?hr without accumulation in the organs. Its discharge from the urine and feces was 16.58?±?4.48% and 3.37?±?0.71%, respectively. All of the results showed that the recovery rate, liner relationship, specificity, stability, and precision of the method were good. The study also proved that 1-methyl hydantoin has been eliminated quite faster in rats. 相似文献
97.
A novel, rapid and sensitive liquid chromatography/quadrupole linear ion trap mass spectrometry [LC‐ESI‐(QqLIT)MS/MS] method was developed and validated for the quantification of protopanaxadiol (PPD) in rat plasma. Oleanolic acid (OA) was used as internal standard (IS). A simple protein precipitation based on acetonitrile (ACN) was employed. Chromatographic separation was performed on a Sepax GP‐C18 column (50 × 2.1 mm, 5 μM) with a mobile phase consisting of ACN–water and 1.5 μM formic acid and 25 mM lithium acetate (90 : 10, v/v) at a flow rate of 0.4 ml/min for 3.0 min. Multiple‐reaction‐monitoring mode was performed using lithium adduct ion as precursor ion of m/z 467.5/449.4 and 455.6/407.4 for the drug and IS, respectively. Calibration curve was recovered over a concentration range of 0.5–100 ng/ml with a correlation coefficient >0.99. The limit of detection was 0.2 ng/ml in rat plasma for PPD. The results of the intraday and interday precision and accuracy studies were well within the acceptable limits. The validated method was successfully applied to investigate the pharmacokinetic study of PPD after intravenous and gavage administration to rat. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
98.
因课程设置、学情等不同, PBL教学模式在中美高校化学实验课的实施过程中各具特色。本文从教材、课程考核、师资培训、研究机构和基金等4个角度客观分析PBL教学模式在中美2国高校化学实验课应用中的差异,并在此基础之上提出,应该客观公正地看待这种差异,树立文化自信。 相似文献
99.
100.