1.
Analysis of chemical variations between raw and wine-processed Ligustri Lucidi Fructus by ultra-high-performance liquid chromatography-Q-Exactive Orbitrap/MS combined with multivariate statistical analysis approach.
Zhang, D, Sun, L, Mao, B, Zhao, D, Cui, Y, Sun, L, Zhang, Y, Zhao, X, Zhao, P, Zhang, X
Biomedical chromatography : BMC. 2021;(4):e5025
Abstract
Ligustri Lucidi Fructus (LLF) is the dried and mature fruit of Ligubtrum lucidum Ait., which has the effect of nourishing the liver and kidney, brightening the eyes and promoting the growth of black hair. Wine-processed LLF is commonly used in traditional Chinese medicine; however, the processing mechanisms are still unclear. Herein, a system data acquisition and mining strategy was designed to investigate the chemical profile differences between the raw and wine-processed LLF, based on high-performance liquid chromatography-Orbitrap high resolution mass spectrometry coupled with multivariate statistical analysis including principal component analysis and partial least square analysis. Afterwars, a total of 55 components were found to be the main contributors to the significant difference between raw and wine-processed LLF by comparison with chromatographic behaviors, intact precursor ions, and characteristic MS fragmentation patterns. In addition, 10 main constituents of raw and wine-processed LLF were simultaneously determined by UHPLC-MS/MS for analyzing the content variations. Some structural transformation mechanisms during wine processing were deduced from the results. The results may provide a scientific foundation for deeply elucidating the wine-processing mechanism of LLF.
2.
UHPLC-MS/MS method for determination of atorvastatin calcium in human plasma: Application to a pharmacokinetic study based on healthy volunteers with specific genotype.
Xia, B, Li, Y, Zhang, Y, Xue, M, Li, X, Xu, P, Xia, T, Chen, S
Journal of pharmaceutical and biomedical analysis. 2018;:428-435
Abstract
A rapid, selective and sensitive ultra high performance liquid chromatography coupled with tandem triple quaternary mass spectrometry (UHPLC-MS/MS) method was developed and validated for the quantitative determination of atorvastatin calcium (AC) in human plasma. Separation of AC and rosuvastatin calcium (internal standard, IS) were achieved on a Dikma Leapsil C18 reversed phase column (100 × 2.1 mm, 2.7 μm) with gradient elution using 0.2% (v/v) formic acid in water and acetonitrile as mobile phases, at the flow rate of 0.3 mL/min. AC and IS were detected using MS/MS with turbo ion pray source in negative mode by monitoring the precursor-to-product ion transitions m/z 557.0→453.0 for AC and m/z 480.0→418.0 for IS. The calibration curves were linear from 0.05 to 50 ng/mL with a correlation coefficient ( r2) of 0.9992 or better. Thereafter, 187 healthy candidates were checked to the genetic polymorphism analysis of SLCO1B1 521T>C(rs4149056), SLCO1B1 388A>G(rs2306283), CYP3A4 1*B(rs2740574), CYP3A4 1*G(rs2242480) and CYP3A5*3(rs776746) using fluorescence in situ hybridization technology. The genotype frequencies of wild-type homozygote, mutant heterozygote and mutant homozygote were 62.57%(TT), 34.22%(TC) and 3.21%(CC) for SLCO1B1 521T>C, and 8.56%(AA), 33.69%(AG) and 57.75%(GG) for SLCO1B1 388A>G, and 62.57%(CC), 34.22%(CT) and 3.21%(TT) for CYP3A4 1 G, and 58.29%(GG), 34.76%(GA) and 6.95%(AA) for CYP3A5*3, respectively. Furthermore, each tested genotype of CYP3A4 1B was wild type. Finally, 5 candidates with specific genotype described above were recruited to carry out the clinical pharmacokinetics of AC (n = 5). The validated UHPLC-MS/MS method was implemented in a high-throughput setting, capable of analyzing up to 288 samples per day, and was successfully applied to the pharmacokinetic study of AC based on healthy volunteers with specific genotype. The Cmax of AC in human volunteers with the specific genotype was nearly 10 times higher than that previous reported, indicating that genetic polymorphisms of these specific genotypes have significant influence on pharmacokinetics of atorvastatin.
3.
Numerical determination of competitive adsorption isotherm of mandelic acid enantiomers on cellulose-based chiral stationary phase.
Zhang, Y, Rohani, S, Ray, AK
Journal of chromatography. A. 2008;(1):34-9
Abstract
The use of inverse method for the determination of competitive adsorption isotherm of mandelic acid enantiomers on cellulose tris(3,5-diethylphenyl carbamate) stationary phase is proposed in this work. Non-dominated sorting genetic algorithm with jumping genes (NSGA-II-JG) was applied to acquire the isotherm parameters by minimizing the sum of square deviations of the model predictions from the measured elution profiles. Three different competitive isotherm models, i.e., Langmuir, biLangmuir and Tóth, combined with transport-dispersive chromatographic model were used in predicting the elution profiles. Orthogonal collocation on finite element (OCFE) method was applied to obtain the calculated elution profiles. Results indicate that biLangmuir isotherm and Tóth isotherm give remarkably similar equilibrium isotherms within the investigated liquid concentration range. Band profiles calculated from both isotherm models are in good agreement with the experimental data. The validity of the determined parameters was verified by comparing the model predictions with experimental elution profiles at various experimental conditions.