In this paper,brinzolamide(S)-isomer was synthesized from 3-(2-bromoacetyl)-5-chloro-2-thiophenesulfonamide over five-step reactions of reduction cyclization,N-alkylation,sulfamation,amino protecting and amination fir...In this paper,brinzolamide(S)-isomer was synthesized from 3-(2-bromoacetyl)-5-chloro-2-thiophenesulfonamide over five-step reactions of reduction cyclization,N-alkylation,sulfamation,amino protecting and amination firstly,in total yield of 23%.The structures were characterized by 1H NMR、MS.The mixture of brinzolamide and its(S)-isomer was analyzed by HPLC indicating the resolution factor was 3.022 between brinzolamide and its(S)-isomer through column selection and factor modulation.The e.e.value of synthesized brinzolamide(S)-isomer was 96.9%.展开更多
A simple, rapid, sensitive and reproducible method for enantiomer analysis of methamphetamine, amphetamine, cathinone and methcathinone was developed and validated. The compounds were extracted from equine plasma and ...A simple, rapid, sensitive and reproducible method for enantiomer analysis of methamphetamine, amphetamine, cathinone and methcathinone was developed and validated. The compounds were extracted from equine plasma and urine using a fast liquid-liquid extraction procedure. Only one milliliter plasma and one hundred microliter urine sample is needed for analysis. The extraction procedure had good recovery (>70%) and the matrix effect was negligible. Enantiomer differentiation and confirmation were achieved using liquid chromatography with chiral stationary phase and mass spectrometry detection. The method demonstrated excellent reproducibility with intra-day and inter-day precision of lower than 5%. The lower limits of detection for all of the compounds studied here were at low pg/mL level for both plasma and urine. This is the first report of the analysis of four chiral compounds in equine plasma and urine. Routine application was demonstrated for (S)- and (R)-enantiomer differentiation.展开更多
The determination of enantiomeric composition by partial least squares （PLS） modeling of UV-vis spectral data was investigated for samples of phenylalanine （phe） using sucrose as a chiral auxiliary. And a new data...The determination of enantiomeric composition by partial least squares （PLS） modeling of UV-vis spectral data was investigated for samples of phenylalanine （phe） using sucrose as a chiral auxiliary. And a new data preprocess method, reference band normalization, was introduced to eliminate the spectral variations due to the changes of total concentration of phe. The determination coefficient （R2） and the standard error of calibration set （SEC） of 13 standard samples are 0.9987 and 0.0128 respectively. The standard error of validation set （SECV） of 7 validation samples is 0.0049. The standard error of predict （SEP） of 6 blind samples for evaluating the robustness of the model is 0.0366. The regression model is robust to determine enantiomeric composition when total concentration varied. It is demonstrated that the reference band normalization is a convenient method of compensating for variations in total concentrations without knowing that in advance.展开更多
A simple,fast and sensitive capillary electrophoresis（CE） strategy combined with chemiluminescence（CL） detection for analysis of ofloxacin（OF） enantiomers was established in the present work.Sulfonated p-cyclode...A simple,fast and sensitive capillary electrophoresis（CE） strategy combined with chemiluminescence（CL） detection for analysis of ofloxacin（OF） enantiomers was established in the present work.Sulfonated p-cyclodextrin（β-CD） was used as the chiral additive being added into the running buffer of luminol-diperiodatocuprate（Ⅲ）（K[Cu（HIO6）2],DPC） chemiluminescence system.Under the optimum conditions,the proposed method was successfully applied to separation and analysis of OF enantiomers with the detection limits（S/N=3） of 8.0 nM and 7.0 nM for levofloxacin and dextrofloxacin,respectively.The linear ranges were both 0.010-100 μM.The method was utilized for analyzing OF in urine;the results obtained were satisfactory and recoveries were 89.5-110.8%,which demonstrated the reliability of this method.This approach can also be further extended to analyze different commercial OF medicines.展开更多
文摘In this paper,brinzolamide(S)-isomer was synthesized from 3-(2-bromoacetyl)-5-chloro-2-thiophenesulfonamide over five-step reactions of reduction cyclization,N-alkylation,sulfamation,amino protecting and amination firstly,in total yield of 23%.The structures were characterized by 1H NMR、MS.The mixture of brinzolamide and its(S)-isomer was analyzed by HPLC indicating the resolution factor was 3.022 between brinzolamide and its(S)-isomer through column selection and factor modulation.The e.e.value of synthesized brinzolamide(S)-isomer was 96.9%.
文摘A simple, rapid, sensitive and reproducible method for enantiomer analysis of methamphetamine, amphetamine, cathinone and methcathinone was developed and validated. The compounds were extracted from equine plasma and urine using a fast liquid-liquid extraction procedure. Only one milliliter plasma and one hundred microliter urine sample is needed for analysis. The extraction procedure had good recovery (>70%) and the matrix effect was negligible. Enantiomer differentiation and confirmation were achieved using liquid chromatography with chiral stationary phase and mass spectrometry detection. The method demonstrated excellent reproducibility with intra-day and inter-day precision of lower than 5%. The lower limits of detection for all of the compounds studied here were at low pg/mL level for both plasma and urine. This is the first report of the analysis of four chiral compounds in equine plasma and urine. Routine application was demonstrated for (S)- and (R)-enantiomer differentiation.
基金supported by the Near-infrared spectra data in the application of evaluating tobacco leaf quality (No.2010YN65)
文摘The determination of enantiomeric composition by partial least squares （PLS） modeling of UV-vis spectral data was investigated for samples of phenylalanine （phe） using sucrose as a chiral auxiliary. And a new data preprocess method, reference band normalization, was introduced to eliminate the spectral variations due to the changes of total concentration of phe. The determination coefficient （R2） and the standard error of calibration set （SEC） of 13 standard samples are 0.9987 and 0.0128 respectively. The standard error of validation set （SECV） of 7 validation samples is 0.0049. The standard error of predict （SEP） of 6 blind samples for evaluating the robustness of the model is 0.0366. The regression model is robust to determine enantiomeric composition when total concentration varied. It is demonstrated that the reference band normalization is a convenient method of compensating for variations in total concentrations without knowing that in advance.
基金financially supported by the Natural Science Foundation of Chongqing(CSTC2013jjB0096)the Fundamental Research Funds for the Central Universities(XDJK2012A002 and XDJK2013A025)the Program for Innovative Research Team in University of Chongqing(2013)
文摘A simple,fast and sensitive capillary electrophoresis（CE） strategy combined with chemiluminescence（CL） detection for analysis of ofloxacin（OF） enantiomers was established in the present work.Sulfonated p-cyclodextrin（β-CD） was used as the chiral additive being added into the running buffer of luminol-diperiodatocuprate（Ⅲ）（K[Cu（HIO6）2],DPC） chemiluminescence system.Under the optimum conditions,the proposed method was successfully applied to separation and analysis of OF enantiomers with the detection limits（S/N=3） of 8.0 nM and 7.0 nM for levofloxacin and dextrofloxacin,respectively.The linear ranges were both 0.010-100 μM.The method was utilized for analyzing OF in urine;the results obtained were satisfactory and recoveries were 89.5-110.8%,which demonstrated the reliability of this method.This approach can also be further extended to analyze different commercial OF medicines.
