The Experts below are selected from a list of 21 Experts worldwide ranked by ideXlab platform
Yuwei Chou - One of the best experts on this subject based on the ideXlab platform.
-
analysis of kanamycin a in human plasma and in oral dosage form by derivatization with 1 Naphthyl Isothiocyanate and high performance liquid chromatography
IEEE Journal of Solid-state Circuits, 2006Co-Authors: Suhwei Chen, Yichian Liang, Yuwei ChouAbstract:A simple and sensitive HPLC method has been developed for trace determination of kanamycin A by derivatization. Plasma proteins are precipitated by acetonitrile and chemical derivatization is performed on the supernatant containing kanamycin A with 1-Naphthyl Isothiocyanate in pyridine at 70 degrees C. After the derivatization reaction, a methylamine/acetonitrile solution was added to the reaction mixture to eliminate the excess of derivatizing agent and shorten the analysis time. The resulting derivative was separated using a Lichrocart Purospher STAR RP-18e column and water/methanol (33:67, v/v) as a mobile phase (detection at 230 nm). Optimization conditions for the derivatization of kanamycin A were investigated by HPLC. The linear range for the quantitation of kanamycin A in spiked plasma was over 1.2-40 microg/mL; the detection limit (signal to noise ratio = 3; injection volume, 10 microL) was about 0.3 microg/mL. The relative standard deviation was less than 2.9% for intra-day assay (n = 6) and inter-day assay (n = 6) and relative recoveries were found to be greater than 98%. Preliminary application of the method for monitoring kanamycin A in humans upon intramuscular injection of the injection product demonstrated the usefulness of the assay for clinical studies. The proposed method can also be used to analyze the compound in pharmaceutical formulations.
Jonas Björklund - One of the best experts on this subject based on the ideXlab platform.
-
LC/MS/MS Analysis of N-Terminal Protein Adducts with Improved Sensitivity: A Comparison of Selected Edman Isothiocyanate Reagents
Hindawi Limited, 2009Co-Authors: Per Rydberg, Hans Von Stedingk, Jörgen Magnér, Jonas BjörklundAbstract:This study provides a basis for a new and straightforward method for LC/MS/MS-based screening of N-terminal protein adducts. This procedure is denoted the “FIRE procedure” as fluorescein Isothiocyanate (FITC) gave superior sensitivity by LC/MS/MS when measuring adducts (R) of electrophilic compounds with a modified Edman procedure. The principles of the FIRE-procedure are that adducts to N-terminal amino acids selectively are detached and measured from of proteins after derivatisation by Isothiocyanate Edman reagents. In this study, FITC, 4-N,N-dimethylaminoazobenzene 4′-Isothiocyanate (DABITC) and 4-dimethylamino-1-Naphthyl Isothiocyanate (DNITC) were used to synthesize thiohydantoin analytes from valine and N-methylvaline. The sensitivity by LC/MS/MS was enhanced by up to three orders of magnitude as compared to phenyl Isothiocyanate and higher as compared to pentafluorophenyl Isothiocyanate. The FITC reagent will enable measurements of low background adduct levels. Synthesized analytes were characterised with, for example, H1 NMR, C13 NMR, LC/MS/MS, and UV
-
doi:10.1155/2009/153472 Research Article LC/MS/MS Analysis of N-Terminal Protein Adducts with Improved Sensitivity: A Comparison of Selected Edman
2009Co-Authors: Isothiocyanate Reagents, Per Rydberg, Hans Von Stedingk, Jörgen Magnér, Jonas BjörklundAbstract:This study provides a basis for a new and straightforward method for LC/MS/MS-based screening of N-terminal protein adducts. This procedure is denoted the “FIRE procedure ” as fluorescein Isothiocyanate (FITC) gave superior sensitivity by LC/MS/MS when measuring adducts (R) of electrophilic compounds with a modified Edman procedure. The principles of the FIRE-procedure are that adducts to N-terminal amino acids selectively are detached and measured from of proteins after derivatisation by Isothiocyanate Edman reagents. In this study, FITC, 4-N,N-dimethylaminoazobenzene 4 ′-Isothiocyanate (DABITC) and 4-dimethylamino-1-Naphthyl Isothiocyanate (DNITC) were used to synthesize thiohydantoin analytes from valine and N-methylvaline. The sensitivity by LC/MS/MS was enhanced by up to three orders of magnitude as compared to phenyl Isothiocyanate and higher as compared to pentafluorophenyl Isothiocyanate. The FITC reagent will enable measurements of low background adduct levels. Synthesized analytes were characterised with, for example, 1 H NMR, 13 C NMR, LC/MS/MS, and UV. Copyright © 2009 Per Rydberg et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 1
Suhwei Chen - One of the best experts on this subject based on the ideXlab platform.
-
analysis of kanamycin a in human plasma and in oral dosage form by derivatization with 1 Naphthyl Isothiocyanate and high performance liquid chromatography
IEEE Journal of Solid-state Circuits, 2006Co-Authors: Suhwei Chen, Yichian Liang, Yuwei ChouAbstract:A simple and sensitive HPLC method has been developed for trace determination of kanamycin A by derivatization. Plasma proteins are precipitated by acetonitrile and chemical derivatization is performed on the supernatant containing kanamycin A with 1-Naphthyl Isothiocyanate in pyridine at 70 degrees C. After the derivatization reaction, a methylamine/acetonitrile solution was added to the reaction mixture to eliminate the excess of derivatizing agent and shorten the analysis time. The resulting derivative was separated using a Lichrocart Purospher STAR RP-18e column and water/methanol (33:67, v/v) as a mobile phase (detection at 230 nm). Optimization conditions for the derivatization of kanamycin A were investigated by HPLC. The linear range for the quantitation of kanamycin A in spiked plasma was over 1.2-40 microg/mL; the detection limit (signal to noise ratio = 3; injection volume, 10 microL) was about 0.3 microg/mL. The relative standard deviation was less than 2.9% for intra-day assay (n = 6) and inter-day assay (n = 6) and relative recoveries were found to be greater than 98%. Preliminary application of the method for monitoring kanamycin A in humans upon intramuscular injection of the injection product demonstrated the usefulness of the assay for clinical studies. The proposed method can also be used to analyze the compound in pharmaceutical formulations.
Yichian Liang - One of the best experts on this subject based on the ideXlab platform.
-
analysis of kanamycin a in human plasma and in oral dosage form by derivatization with 1 Naphthyl Isothiocyanate and high performance liquid chromatography
IEEE Journal of Solid-state Circuits, 2006Co-Authors: Suhwei Chen, Yichian Liang, Yuwei ChouAbstract:A simple and sensitive HPLC method has been developed for trace determination of kanamycin A by derivatization. Plasma proteins are precipitated by acetonitrile and chemical derivatization is performed on the supernatant containing kanamycin A with 1-Naphthyl Isothiocyanate in pyridine at 70 degrees C. After the derivatization reaction, a methylamine/acetonitrile solution was added to the reaction mixture to eliminate the excess of derivatizing agent and shorten the analysis time. The resulting derivative was separated using a Lichrocart Purospher STAR RP-18e column and water/methanol (33:67, v/v) as a mobile phase (detection at 230 nm). Optimization conditions for the derivatization of kanamycin A were investigated by HPLC. The linear range for the quantitation of kanamycin A in spiked plasma was over 1.2-40 microg/mL; the detection limit (signal to noise ratio = 3; injection volume, 10 microL) was about 0.3 microg/mL. The relative standard deviation was less than 2.9% for intra-day assay (n = 6) and inter-day assay (n = 6) and relative recoveries were found to be greater than 98%. Preliminary application of the method for monitoring kanamycin A in humans upon intramuscular injection of the injection product demonstrated the usefulness of the assay for clinical studies. The proposed method can also be used to analyze the compound in pharmaceutical formulations.
Per Rydberg - One of the best experts on this subject based on the ideXlab platform.
-
LC/MS/MS Analysis of N-Terminal Protein Adducts with Improved Sensitivity: A Comparison of Selected Edman Isothiocyanate Reagents
Hindawi Limited, 2009Co-Authors: Per Rydberg, Hans Von Stedingk, Jörgen Magnér, Jonas BjörklundAbstract:This study provides a basis for a new and straightforward method for LC/MS/MS-based screening of N-terminal protein adducts. This procedure is denoted the “FIRE procedure” as fluorescein Isothiocyanate (FITC) gave superior sensitivity by LC/MS/MS when measuring adducts (R) of electrophilic compounds with a modified Edman procedure. The principles of the FIRE-procedure are that adducts to N-terminal amino acids selectively are detached and measured from of proteins after derivatisation by Isothiocyanate Edman reagents. In this study, FITC, 4-N,N-dimethylaminoazobenzene 4′-Isothiocyanate (DABITC) and 4-dimethylamino-1-Naphthyl Isothiocyanate (DNITC) were used to synthesize thiohydantoin analytes from valine and N-methylvaline. The sensitivity by LC/MS/MS was enhanced by up to three orders of magnitude as compared to phenyl Isothiocyanate and higher as compared to pentafluorophenyl Isothiocyanate. The FITC reagent will enable measurements of low background adduct levels. Synthesized analytes were characterised with, for example, H1 NMR, C13 NMR, LC/MS/MS, and UV
-
doi:10.1155/2009/153472 Research Article LC/MS/MS Analysis of N-Terminal Protein Adducts with Improved Sensitivity: A Comparison of Selected Edman
2009Co-Authors: Isothiocyanate Reagents, Per Rydberg, Hans Von Stedingk, Jörgen Magnér, Jonas BjörklundAbstract:This study provides a basis for a new and straightforward method for LC/MS/MS-based screening of N-terminal protein adducts. This procedure is denoted the “FIRE procedure ” as fluorescein Isothiocyanate (FITC) gave superior sensitivity by LC/MS/MS when measuring adducts (R) of electrophilic compounds with a modified Edman procedure. The principles of the FIRE-procedure are that adducts to N-terminal amino acids selectively are detached and measured from of proteins after derivatisation by Isothiocyanate Edman reagents. In this study, FITC, 4-N,N-dimethylaminoazobenzene 4 ′-Isothiocyanate (DABITC) and 4-dimethylamino-1-Naphthyl Isothiocyanate (DNITC) were used to synthesize thiohydantoin analytes from valine and N-methylvaline. The sensitivity by LC/MS/MS was enhanced by up to three orders of magnitude as compared to phenyl Isothiocyanate and higher as compared to pentafluorophenyl Isothiocyanate. The FITC reagent will enable measurements of low background adduct levels. Synthesized analytes were characterised with, for example, 1 H NMR, 13 C NMR, LC/MS/MS, and UV. Copyright © 2009 Per Rydberg et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 1
