1
|
Keuler T, Wolf V, Lemke C, Voget R, Braune A, Gütschow M. Fluorogenic substrates and pre-column derivatization for monitoring the activity of bile salt hydrolase from Clostridium perfringens. Bioorg Chem 2023; 138:106574. [PMID: 37163789 DOI: 10.1016/j.bioorg.2023.106574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 04/13/2023] [Accepted: 04/24/2023] [Indexed: 05/12/2023]
Abstract
The bile acid pool has a profound impact on human health and disease. The intestinal microbiota initiates the metabolism of conjugated bile acids through a critical first step catalyzed by bacterial bile salt hydrolase (BSH) and provides unique contributions to the diversity of bile acids. There has been great interest in surveying BSH activity. We compared two substrates with either 2-(7-amino-4-methyl-coumarinyl)acetic acid or 7-amino-4-methyl-coumarin as fluorescent reporters of BSH activity. The BSH-catalyzed conversion of the natural substrate taurocholic acid was followed through an HPLC-based assay by applying 7-nitrobenzo[c][1,2,5]oxadiazole as scavenger for taurine, released in the enzymatic reaction. Hence, a new opportunity to monitor the activity of bile salt hydrolases was introduced.
Collapse
Affiliation(s)
- Tim Keuler
- Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
| | - Valentina Wolf
- Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
| | - Carina Lemke
- Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
| | - Rabea Voget
- Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
| | - Annett Braune
- Research Group Intestinal Microbiology, German Institute of Human Nutrition Potsdam-Rehbruecke, Arthur-Scheunert-Allee 114-116, D-14558 Nuthetal, Germany.
| | - Michael Gütschow
- Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany.
| |
Collapse
|
2
|
Dutra JAP, Luiz MT, Tavares Junior AG, Di Filippo LD, Carvalho SG, Chorilli M. Temozolomide: an Overview of Biological Properties, Drug Delivery Nanosystems, and Analytical Methods. Curr Pharm Des 2022; 28:2073-2088. [PMID: 35658888 DOI: 10.2174/1381612828666220603152918] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 04/19/2022] [Indexed: 11/22/2022]
Abstract
Temozolomide (TMZ) is an imidazotetrazine prodrug used to treat glioblastoma multiforme. Its physicochemical prop-erties and small size confer the ability to cross the blood-brain barrier. The antitumor activity depends on pH-dependent hydrolysis of the methyldiazonium cation, which is capable of methylating purine bases (O6-guanine; N7-guanine, and N3-adenine) and causing DNA damage and cell death. TMZ is more stable in acidic media (pH ≤ 5.0) than in basic media (pH ≥ 7.0) due to the protonated form that minimizes the catalytic process. Because of this, TMZ has high oral bioavailability, but it has a half-life of 1.8 h and low brain distribution (17.8%), requiring a repeated dos-ing regimen that limits its efficacy and increases adverse events. Drug delivery Nanosystems (DDNs) improve the phys-icochemical properties of TMZ and may provide controlled and targeted delivery. Therefore, DDNs can increase the efficacy and safety of TMZ. In this context, to ensure the efficiency of DDNs, analytical methods are used to evaluate TMZ pharmacokinetic parameters, encapsulation efficiency, and the release profile of DDNs. Among the methods, high-performance liquid chromatography is the most used due to its detection sensitivity in complex matrices such as tissues and plasma. Micellar electrokinetic chromatography features fast analysis and no sample pretreatment. Spec-trophotometric methods are still used to determine encapsulation efficiency due to their low cost, despite their low sen-sitivity. This review summarizes the physicochemical and pharmacological properties of free TMZ and TMZ-loaded DDNs. In addition, this review addresses the main analytical methods employed to characterize TMZ in different ma-trices.
Collapse
Affiliation(s)
| | - Marcela Tavares Luiz
- School of Pharmaceutical Science of Ribeirao Preto, University of Sao Paulo (USP), Ribeirao Preto, São Paulo, Bra-zil
| | | | | | - Suzana Gonçalves Carvalho
- School of Pharmaceutical Science of Sao Paulo State University (UNESP), Araraquara, Sao Paulo, Brazil
| | - Marlus Chorilli
- School of Pharmaceutical Science of Sao Paulo State University (UNESP), Araraquara, Sao Paulo, Brazil
| |
Collapse
|
3
|
Chiral Micellar Electrokinetic Chromatography. J Chromatogr A 2020; 1626:461383. [PMID: 32797856 DOI: 10.1016/j.chroma.2020.461383] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 06/29/2020] [Accepted: 06/30/2020] [Indexed: 12/18/2022]
Abstract
The potential of Micellar Electrokinetic Chromatography to achieve enantiomeric separations is reviewed in this article. The separation principles and the most frequently employed separation strategies to achieve chiral separations by Micellar Electrokinetic Chromatography are described. The use of chiral micellar systems alone or combined with other micellar systems or chiral selectors, as well as of mixtures of achiral micellar systems with chiral selectors is discussed together with the effect of different additives present in the separation medium. Indirect methods based on the derivatization of analytes with chiral derivatizing reagents and the use of achiral micelles are also considered. Preconcentration techniques employed to improve sensitivity and the main approaches developed to facilitate the coupling with Mass Spectrometry are included. The most recent and relevant methodologies developed by chiral Micellar Electrokinetic Chromatography and their applications in different fields are presented.
Collapse
|
4
|
Ko HY, Lin YH, Shih CJ, Chen YL. Determination of phenylenediamines in hair colors derivatizated with 5-(4, 6-dichlorotriazinyl)aminofluorescein via micellar electrokinetic chromatography. J Food Drug Anal 2019; 27:825-831. [PMID: 31324298 PMCID: PMC9307028 DOI: 10.1016/j.jfda.2019.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 02/24/2019] [Accepted: 02/27/2019] [Indexed: 11/11/2022] Open
Abstract
Phenylenediamines (PDs), which are reported to cause allergic dermatitis and possess genotoxicity and carcinogenicity, are the ingredients used in permanent hair dyes. The fluorescent derivatization strategy coupled with micellar electrokinetic chromatography (MEKC) were established to analyze four PDs, including o-phenylenediamine (OPD), m-phenylenediamine (MPD), p-phenylenediamine (PPD) and toluene-2,5-diamine (PTD). Additionally, 5-(4, 6-dichlorotriazinyl) aminofluorescein (DTAF) was used as a fluorescent reagent derived at amino groups of PDs and underwent nucleophilic substitution reaction to improve the detection sensitivity. The derivatization condition reacted at 90 °C for 10 min in alkaline conditions. The optimized separation conditions were 20 mM borate (pH 8.0) containing 10 mM Brij 35 and 35% (v/v) methanol. The limits of detection (S/N = 3) for MPD, PTD, PPD and OPD were 25, 25, 50 and 100 nM, respectively. Compared to MEKC-UV, the sensitivity enhancements were 30- to 81-fold when PDs were derived with DTAF. The high-sensitivity MEKC-LIF method was successfully established and applied to determine PDs in commercial hair colors for quality control and in real hair samples for evaluating the location of PDs in dyed hair samples, as well as in percutaneous absorption samples for evaluating the ability of PDs to penetrate skin.
Collapse
Affiliation(s)
- Hung-Yu Ko
- Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yi-Hui Lin
- School of Pharmacy, College of Pharmacy, China Medical University, Taichung, Taiwan
| | - Chi-Jen Shih
- Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yen-Ling Chen
- Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Marine Biotechnology and Resources, College of Marine Sciences National Sun Yat-Sen University, Kaohsiung, Taiwan; Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
| |
Collapse
|
5
|
Wu D, Yang J, Cai Y, Lin X, Yan J, Li H. Simultaneous Determination of Two Amino Bisphosphonates Drugs by Micellar Electrokinetic Chromatography. J Chromatogr Sci 2015; 53:1794-800. [DOI: 10.1093/chromsci/bmv074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Indexed: 11/13/2022]
|
6
|
Liquid extraction surface analysis in-line coupled with capillary electrophoresis for direct analysis of a solid surface sample. Anal Chim Acta 2014; 838:45-50. [DOI: 10.1016/j.aca.2014.05.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 05/06/2014] [Accepted: 05/09/2014] [Indexed: 11/19/2022]
|
7
|
Korchane S, Pallandre A, Przybylski C, Poüs C, Gonnet F, Taverna M, Daniel R, Le Potier I. Derivatization strategies for CE-LIF analysis of biomarkers: Toward a clinical diagnostic of familial transthyretin amyloidosis. Electrophoresis 2014; 35:1050-9. [DOI: 10.1002/elps.201300426] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 10/31/2013] [Accepted: 10/31/2013] [Indexed: 11/10/2022]
Affiliation(s)
- Sonia Korchane
- Faculté de Pharmacie; Université Paris-Sud; Châtenay-Malabry; France
- CNRS, Institut Galien Paris-Sud; UMR 8612, Châtenay-Malabry; France
| | - Antoine Pallandre
- Faculté de Pharmacie; Université Paris-Sud; Châtenay-Malabry; France
- CNRS, Institut Galien Paris-Sud; UMR 8612, Châtenay-Malabry; France
| | - Cédric Przybylski
- Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement; Université Evry-Val-d’Essonne; Evry France
- CNRS; Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement; UMR 8587 Evry France
| | - Christian Poüs
- Faculté de Pharmacie; Université Paris-Sud; EA4530 Châtenay-Malabry France
- Hôpital Antoine Béclère AP-HP; Service de Biochimie; Clamart France
| | - Florence Gonnet
- Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement; Université Evry-Val-d’Essonne; Evry France
- CNRS; Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement; UMR 8587 Evry France
| | - Myriam Taverna
- Faculté de Pharmacie; Université Paris-Sud; Châtenay-Malabry; France
- CNRS, Institut Galien Paris-Sud; UMR 8612, Châtenay-Malabry; France
| | - Régis Daniel
- Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement; Université Evry-Val-d’Essonne; Evry France
- CNRS; Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement; UMR 8587 Evry France
| | - Isabelle Le Potier
- Faculté de Pharmacie; Université Paris-Sud; Châtenay-Malabry; France
- CNRS, Institut Galien Paris-Sud; UMR 8612, Châtenay-Malabry; France
| |
Collapse
|
8
|
Breadmore MC, Shallan AI, Rabanes HR, Gstoettenmayr D, Abdul Keyon AS, Gaspar A, Dawod M, Quirino JP. Recent advances in enhancing the sensitivity of electrophoresis and electrochromatography in capillaries and microchips (2010-2012). Electrophoresis 2013; 34:29-54. [PMID: 23161056 DOI: 10.1002/elps.201200396] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 09/03/2012] [Accepted: 09/04/2012] [Indexed: 12/21/2022]
Abstract
CE has been alive for over two decades now, yet its sensitivity is still regarded as being inferior to that of more traditional methods of separation such as HPLC. As such, it is unsurprising that overcoming this issue still generates much scientific interest. This review continues to update this series of reviews, first published in Electrophoresis in 2007, with updates published in 2009 and 2011 and covers material published through to June 2012. It includes developments in the field of stacking, covering all methods from field amplified sample stacking and large volume sample stacking, through to isotachophoresis, dynamic pH junction and sweeping. Attention is also given to online or inline extraction methods that have been used for electrophoresis.
Collapse
Affiliation(s)
- Michael C Breadmore
- Australian Centre for Research on Separation Science, School of Chemistry, University of Tasmania, Hobart, Tasmania, Australia.
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Lorenzo MP, Villaseñor A, Ramamoorthy A, Garcia A. Optimization and validation of a capillary electrophoresis laser-induced fluorescence method for amino acids determination in human plasma: application to bipolar disorder study. Electrophoresis 2013; 34:1701-9. [PMID: 23512402 DOI: 10.1002/elps.201200632] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 02/06/2013] [Accepted: 02/07/2013] [Indexed: 11/05/2022]
Abstract
Quantitative and qualitative analysis of amino acids in biofluids offers relevant information in diagnosis of diseases, evaluation of nutritional state, and in elucidating metabolic influences on physiology. A simple, rapid, and robust procedure in terms of sample treatment, separation, and quantitation based on CE-LIF has been optimized for use in human plasma samples. Time required for derivatization was 15 min and analysis time was 35 min. 4-Fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) was the labeling agent used for obtaining fluorescent derivatives. Electrophoretic conditions were: 175 mM borate buffer at pH 10.25 prepared with 12.5 mM β-cyclodextrin. The voltage applied was +21 kV. Fourteen amino acids could be quantified: L-proline, L-phenylalanine, L-leucine, L-isoleucine, L-ornithine, D-ornithine, L-glutamine, L-alanine, L-threonine, glycine, L-serine, D-serine, taurine and L-glutamate. With this chiral CE-LIF method, L- and D-amino acids are adequately separated. The method was validated for a representative group of amino acids in human plasma: L-proline, L-isoleucine, L-ornithine, L-glutamine, L-alanine L-threonine, glycine, L-serine, D-serine, and glutamate. The method has been successfully applied to human plasma from patients with bipolar disorder, all of whom were taking lithium as a mood stabilizer. Eleven amino acids were quantified in plasma from nine patients, aged 24-55 years. The results were in accordance to published values for the bipolar patients. The method is useful particularly in studies where plasma amino acid levels can be used as biomarkers for diagnosis of diseases, evaluating the disease progression, and monitoring response to drug therapy.
Collapse
Affiliation(s)
- Ma Paz Lorenzo
- Center for Metabolomics and Bioanalysis (CEMBIO), Facultad de Farmacia, Universidad CEU San Pablo, Campus Montepríncipe, Madrid, Spain
| | | | | | | |
Collapse
|
10
|
Optimization and validation of a CE-LIF method for amino acid determination in biological samples. J Pharm Biomed Anal 2013; 73:116-24. [PMID: 22482900 DOI: 10.1016/j.jpba.2012.03.017] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 03/06/2012] [Accepted: 03/08/2012] [Indexed: 11/23/2022]
|
11
|
Single-drop microextraction as a powerful pretreatment tool for capillary electrophoresis: A review. Anal Chim Acta 2012; 739:14-24. [DOI: 10.1016/j.aca.2012.06.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 06/02/2012] [Accepted: 06/02/2012] [Indexed: 01/16/2023]
|
12
|
Wagner Z, Tábi T, Zachar G, Csillag A, Szökő É. Comparison of quantitative performance of three fluorescence labels in CE/LIF analysis of aspartate and glutamate in brain microdialysate. Electrophoresis 2011; 32:2816-22. [DOI: 10.1002/elps.201100032] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
13
|
Szökő É, Tábi T. Analysis of biological samples by capillary electrophoresis with laser induced fluorescence detection. J Pharm Biomed Anal 2010; 53:1180-92. [DOI: 10.1016/j.jpba.2010.07.045] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Revised: 07/23/2010] [Accepted: 07/27/2010] [Indexed: 12/26/2022]
|
14
|
Highly sensitive chiral analysis of amino acids by in-line single drop microextraction and capillary electrophoresis with laser-induced fluorescence detection. Anal Chim Acta 2010; 677:37-42. [DOI: 10.1016/j.aca.2010.03.050] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2009] [Revised: 03/02/2010] [Accepted: 03/24/2010] [Indexed: 11/18/2022]
|
15
|
Genady AR. Synthesis and characterization of novel color chemosensors based on azo dyes for possible application in opioid pharmacology. J Heterocycl Chem 2010. [DOI: 10.1002/jhet.436] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
16
|
Başkan S, Tezcan F, Köse S, Öztekin N, Erim FB. Non-ionic micellar electrokinetic chromatography with laser-induced fluorescence: A new method tested with biogenic amines in brined and dry-salted fish. Electrophoresis 2010; 31:2174-9. [DOI: 10.1002/elps.200900683] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
|
17
|
Park YK, Choi K, Ahmed AYBH, ALOthman ZA, Chung DS. Selective preconcentration of amino acids and peptides using single drop microextraction in-line coupled with capillary electrophoresis. J Chromatogr A 2010; 1217:3357-61. [DOI: 10.1016/j.chroma.2010.03.029] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Revised: 03/15/2010] [Accepted: 03/17/2010] [Indexed: 11/24/2022]
|
18
|
|
19
|
Alnajjar AA. Capillary electrophoresis with fluorescence detection for sensitive analysis of morphine and 6-acetylmorphine in human urine. ACTA CHROMATOGR 2008. [DOI: 10.1556/achrom.20.2008.2.7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
20
|
Nonaqueous capillary electrophoresis with laser-induced fluorescence detection: A case study of comparison with aqueous media. Anal Chim Acta 2008; 611:212-9. [DOI: 10.1016/j.aca.2008.01.084] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Revised: 01/25/2008] [Accepted: 01/28/2008] [Indexed: 11/22/2022]
|
21
|
Alnajjar AO, El-Zaria ME. Synthesis and characterization of novel azo-morphine derivatives for possible use in abused drugs analysis. Eur J Med Chem 2008; 43:357-63. [PMID: 17524526 DOI: 10.1016/j.ejmech.2007.03.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Revised: 03/26/2007] [Accepted: 03/29/2007] [Indexed: 11/21/2022]
Abstract
A new simple and fast spectroscopic method was presented as a new marker for heroin use. Novel azo-morphine derivatives with spectroscopic absorption peaks ranging from 330-470 nm, were synthesized by the coupling of morphine (M) and 6-acetyl morphine (6-AM) with freshly prepared diazonium salt of aniline hydrochloride at 0 degrees C. However, no reaction was observed with codeine under the same reaction conditions. Separation of azo dyes was performed by TLC using tetrahydrofuran and dichloromethane in the ratio 1:1. The chemical structure of the products was established by their microanalysis, NMR, IR, UV-vis, and mass spectroscopies. Electronic absorption and excitation spectra of the dyes were measured in solvents of different polarities. The dyes exhibited positive solvatochromism, i.e., a bathochromic band shift as the solvent polarity is increased. Also, the fluorescence quantum yield was sensitive to the polarity and the pH of the medium. The UV-vis spectroscopy of spiked compounds in human urine samples was also reported. The drugs (M, 6-AM and mixture of both) were coupled with freshly prepared diazonium salt even at very low concentration of the drugs 10(-9)M.
Collapse
Affiliation(s)
- Ahmed O Alnajjar
- Department of Chemistry, College of Science, King Faisal University, P.O. Box 380, 31982 Hofuf, Saudi Arabia.
| | | |
Collapse
|
22
|
Iadarola P, Ferrari F, Fumagalli M, Viglio S. Determination of amino acids by micellar EKC: Recent advances in method development and novel applications to different matrices. Electrophoresis 2008; 29:224-36. [DOI: 10.1002/elps.200700662] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
23
|
Cai J, Li P. Chemical Separation of Bioactive Licorice Compounds Using Capillary Electrophoresis. J LIQ CHROMATOGR R T 2007. [DOI: 10.1080/10826070701588489] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Jia Cai
- a Department of Chemistry , Simon Fraser University , Burnaby, BC, Canada
| | - Paul Li
- a Department of Chemistry , Simon Fraser University , Burnaby, BC, Canada
| |
Collapse
|
24
|
Ciriacks Klinker C, Bowser MT. 4-Fluoro-7-nitro-2,1,3-benzoxadiazole as a Fluorogenic Labeling Reagent for the in Vivo Analysis of Amino Acid Neurotransmitters Using Online Microdialysis−Capillary Electrophoresis. Anal Chem 2007; 79:8747-54. [DOI: 10.1021/ac071433o] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Chanda Ciriacks Klinker
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455
| | - Michael T. Bowser
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455
| |
Collapse
|
25
|
Chen S, Xu Y, Xu F, Feng X, Du W, Luo Q, Liu BF. Separation and determination of amino acids by micellar electrokinetic chromatography coupling with novel multiphoton excited fluorescence detection. J Chromatogr A 2007; 1162:149-53. [PMID: 17560588 DOI: 10.1016/j.chroma.2007.05.046] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Revised: 05/14/2007] [Accepted: 05/14/2007] [Indexed: 11/29/2022]
Abstract
In this article, it was demonstrated that separation and determination of 20 amino acids were accomplished by micellar electrokinetic chromatography (MEKC) coupling with novel multiphoton excited fluorescence (MPEF) detection method. Different from MPEF achieved by expensive fs laser, continuous wave (CW) diode laser of ultra-low cost was uniquely employed in our MPEF system. Amino acids were fluorescently labeled with fluorescein isothiocyanate (FITC), and were subjected to sodium dodecyl sulfate (SDS)-based MEKC separation and CW-based MPEF detection. The result was compared with that by single photon excited fluorescence (SPEF), which indicated that MPEF had the advantages of better mass detectability and higher separation selectivity over SPEF. Quantitative analysis was performed and revealed linear dynamic range of over 2 orders of magnitude, with mass detection limit down to ymole level. To evaluate the reliability, this method was successfully applied for analyzing a commercial nutrition supplement liquid.
Collapse
Affiliation(s)
- Sheng Chen
- The Key Laboratory of Biomedical Photonics of MOE - Hubei Bioinformatics and Molecular Imaging Key Laboratory, Department of Systems Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | | | | | | | | | | | | |
Collapse
|
26
|
Sano M, Nishino I. Assay for spermidine synthase activity by micellar electrokinetic chromatography with laser-induced fluorescence detection. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 845:80-3. [PMID: 16931179 DOI: 10.1016/j.jchromb.2006.07.052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2006] [Revised: 06/23/2006] [Accepted: 07/24/2006] [Indexed: 11/29/2022]
Abstract
An assay for spermidine synthase (SPDS) activity in rat liver has been developed using micellar electrokinetic chromatography (MEKC) with laser-induced fluorescence (LIF) detection to enable the discovery of SPDS inhibitors. The assay was established by estimating the amount of spermidine (SPD) produced from the putrescine (PUT) present by SPDS. The SPD in an enzyme reaction mixture of homogenized rat liver could directly react with 7-fluoro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-F) as a fluorescence derivatization reagent. The NBD derivatives of SPD and PUT could be separated and detected by MEKC-LIF detection within 15 min. The IC(50) value measured for SPDS inhibitor, 4-methylcyclohexylamine, in rat liver by this assay was consistent with published data. Our SPDS assay using MEKC-LIF is simple and allows easy determination of SPDS activity in homogenized samples without troublesome procedures such as preparation of antibody or fluorescence-labeled substrate. The assay should be effective for discovering the SPDS inhibitors using biological samples.
Collapse
Affiliation(s)
- Masatake Sano
- Shionogi Research Laboratories, Shionogi & Co. Ltd., 12-4, Sagisu-5-Chome, Osaka 553-0002, Japan.
| | | |
Collapse
|
27
|
Zhang H, Le Potier I, Smadja C, Zhang J, Taverna M. Fluorescent detection of peptides and amino acids for capillary electrophoresis via on-line derivatization with 4-fluoro-7-nitro-2,1,3-benzoxadiazole. Anal Bioanal Chem 2006; 386:1387-94. [PMID: 16953320 DOI: 10.1007/s00216-006-0709-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2006] [Revised: 07/22/2006] [Accepted: 07/25/2006] [Indexed: 10/24/2022]
Abstract
An in-capillary derivatization of amino acids and peptides with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) was developed for their subsequent capillary electrophoretic analysis with laser-induced fluorescence detection (lambda (ex)=488 nm). The in-capillary derivatization was achieved in zone-passing mode by introducing successive plugs of sample and NBD-F into a fused silica capillary previously equilibrated with an alkaline borate buffer. To prevent NBD-F hydrolysis and to achieve a reliable derivatization, NBD-F was prepared daily in absolute ethanol and a plug of absolute ethanol was introduced between the sample and NBD-F reagent plugs. Various parameters influencing the derivatization efficiency were investigated and the optimum conditions were as follows: background electrolyte (BGE), 20 mM borate buffer (pH 8.8); introduction time, 4 s for sample and 2 s for NBD-F; molar ratio of NBD-F/sample, above 215; temperature, 45 degrees C for amino acids and 35 degrees C for peptides; applied voltage, +15 kV. The validation of the in-capillary derivatization method under optimal conditions showed a good linearity between the heights of the derivative peaks and the concentrations of the amino acids. The intra-day relative standard deviations of the migration times and the peak heights were less than 1.3% and 4.6%, respectively. The efficient derivatization and separation of a mixture of valine, alanine, glutamic acid and aspartic acid were achieved using this technique. Peptides such as buccaline and beta-protein fragment 1-42 could also be derivatized using the developed in-capillary derivatization procedure.
Collapse
Affiliation(s)
- Hongyi Zhang
- College of Chemistry and Environmental Science, Hebei University, Baoding 071002, People's Republic of China.
| | | | | | | | | |
Collapse
|
28
|
Santana Rodríguez JJ, Halko R, Betancort Rodríguez JR, Aaron JJ. Environmental analysis based on luminescence in organized supramolecular systems. Anal Bioanal Chem 2006; 385:525-45. [PMID: 16601954 DOI: 10.1007/s00216-006-0342-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2005] [Revised: 01/26/2006] [Accepted: 01/27/2006] [Indexed: 11/26/2022]
Abstract
The use of organized supramolecular systems-including micellar media and cyclodextrin inclusion complexes-combined with luminescence techniques in the study and determination of compounds and elements of environmental interest from 1990 to 2005 is reviewed. Analyses of environmental samples performed using fluorescence, photochemically induced fluorescence and phosphorescence spectroscopy as well as liquid chromatography, capillary electrophoresis and flow injection with luminescence detection in the presence of these organized media are described in detail.
Collapse
Affiliation(s)
- J J Santana Rodríguez
- Department of Chemistry, Faculty of Marine Sciences, University of Las Palmas de G.C., 35017 Las Palmas, Spain
| | | | | | | |
Collapse
|
29
|
Zhang LY, Sun MX. Selective determination of gamma-aminobutyric acid, glutamate and alanine by mixed micellar electrokinetic chromatography and fluorescence detection. J Chromatogr A 2005; 1095:185-8. [PMID: 16221476 DOI: 10.1016/j.chroma.2005.09.050] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2005] [Revised: 09/10/2005] [Accepted: 09/22/2005] [Indexed: 11/30/2022]
Abstract
A mixed micellar electrokinetic chromatography method with fluorescence detection was developed to simultaneously monitor gamma-aminobutyric acid (GABA), glutamate (Glu) and alanine (Ala) in biological samples. Amino acids were derivatized with naphthalene-2,3-dicarboxaldehyde (NDA). The separation of three NDA-labeled isomers (GABA, alpha-ABA, beta-ABA) was studied in detail with different micelles solutions such as sodium dodecyl sulfate (SDS), beta-cyclodextrin (beta-CD) and sodium cholate (SC). Simultaneous resolution of GABA, Glu and Ala from 21 amino acids was achieved within 5 min using 20 mM phosphate buffer at pH 8.7 containing 24 mM SC and 26 mM SDS. The detection limits were 4.0 x 10(-8), 1.1 x 10(-8) and 1.3 x 10(-8) M, for GABA, Glu and Ala, respectively, with S/N = 2. The method was applied to monitor the changes of amount of GABA, Glu and Ala in tobacco leaf in response to cold and dark stress.
Collapse
Affiliation(s)
- Li-Yao Zhang
- Key Laboratory of MOE for Plant Development Biology, College of Life Sciences, Wuhan University, China
| | | |
Collapse
|
30
|
Zhao S, Yuan H, Xiao D. Detection of d-Serine in rat brain by capillary electrophoresis with laser induced fluorescence detection. J Chromatogr B Analyt Technol Biomed Life Sci 2005; 822:334-8. [PMID: 16005268 DOI: 10.1016/j.jchromb.2005.06.027] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2004] [Revised: 05/30/2005] [Accepted: 06/09/2005] [Indexed: 10/25/2022]
Abstract
A capillary zone electrophoresis method with laser induced fluorescence detection for the chiral separation of highly fluorescent enantiomeric derivatives of d/l-Serine from 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-d/l-Serine) was developed and optimized. Enantiomeric separation of NBD-d/l-Serine was accomplished by using 40 mM hydroxypropyl-beta-cyclodextrin (HP-beta-CD) contained in 100 mM borate buffer, pH 10.0. A 70 cm (effective length of 50 cm) uncoated fused-silica capillary at a voltage of 15 kV was used for the separation. The optimized electrophoretic conditions were subsequently applied to the analysis of d-Serine in rat brain, and satisfactory analytical results with respect to accuracy were obtained. This assay showed acceptable precision, with linearity in the d-Serine concentration range of 0.2-20.0 microM. The limit of detection for d-Serine was 3.0 x 10(-7)M.
Collapse
Affiliation(s)
- Shulin Zhao
- College of Chemical Engineering, Sichuan University, Chengdu 610065, China.
| | | | | |
Collapse
|
31
|
O'Brien KB, Miller RF, Bowser MT. d-Serine uptake by isolated retinas is consistent with ASCT-mediated transport. Neurosci Lett 2005; 385:58-63. [PMID: 15950382 DOI: 10.1016/j.neulet.2005.05.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2005] [Revised: 04/26/2005] [Accepted: 05/06/2005] [Indexed: 10/25/2022]
Abstract
Uptake of the neuromodulator D-serine by isolated larval tiger salamander (Ambystoma tigrinum) retinas was measured using capillary electrophoresis (CE). Excised retinas were incubated in Ringer's solution in the presence of 5 microM D-serine. The supernatant was removed after 30 min, mixed with 4-fluoro-7-nitrobenz-2-oxa-1,3-diazole (NBD-F) to fluorescently label amines and analyzed using CE. Significant D-serine uptake was observed over a period of 1.5h. This is the first observation of D-serine uptake by an intact retinal tissue. D-Serine uptake in the retina was Na(+)-dependent and blocked by l-alanine, l-threonine, and l-cysteine. This pharmacology is consistent with the sodium dependent heteroexchange expected of system ASC-type transporters.
Collapse
Affiliation(s)
- Kylie B O'Brien
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | | | | |
Collapse
|
32
|
Zhu X, Shaw PN, Pritchard J, Newbury J, Hunt EJ, Barrett DA. Amino acid analysis by micellar electrokinetic chromatography with laser-induced fluorescence detection: application to nanolitre-volume biological samples from Arabidopsis thaliana and Myzus persicae. Electrophoresis 2005; 26:911-919. [PMID: 15714547 DOI: 10.1002/elps.200410259] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Amino acids were derivatised with 4-fluoro-7-nitrobenzo-2,1,3-oxadiazol (NBD-F), separated by micellar electrokinetic chromatography (MEKC), and detected by argon-ion (488 nm) laser-induced fluorescence. The optimised MEKC background electrolyte conditions were: 40 mM sodium cholate, 5 mM beta-cyclodextrin in 20 mM aqueous borate buffer, pH 9.1, with 7% v/v acetonitrile. Using these conditions, 19 amino acids were separated within 17 min. The limits of detection were in the range of 7.6-42.2 pmol/mL and limits of quantitation from 0.05-0.14 nmol/mL. The method was systematically validated for injection volume error, migration time variation, calibration linearity, accuracy, precision, and recovery. Nanolitre volume samples of phloem sap of individual sieve element cells from the plant Arabidopsis thaliana and honeydew from the aphid Myzus persicae were directly analysed with this method. Quantitative amino acid concentrations in these two biological matrices were profiled for the first time. This method is particularly important because it allows the complete profile of the amino acids obtained from individual phloem elements, allowing cell to cell and plant to plant variation to be quantified, which to date has not been possible with Arabidopsis thaliana.
Collapse
Affiliation(s)
- Xunlin Zhu
- Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham, UK
| | | | | | | | | | | |
Collapse
|
33
|
Liu X, Li DF, Wang Y, Lu YT. Determination of 1-aminocyclopropane-1-carboxylic acid in apple extracts by capillary electrophoresis with laser-induced fluorescence detection. J Chromatogr A 2004; 1061:99-104. [PMID: 15633749 DOI: 10.1016/j.chroma.2004.10.067] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A rapid and sensitive method for the determination of 1-aminocyclopropane-1-carboxylic acid (ACC) in apple tissues has been described. This method is based on the derivatization of ACC with 3-(2-furoyl)quinoline-2-carboxaldehyde (FQ), and separation and quantification of the resulting FQ-ACC derivative by capillary electrophoresis coupled to laser-induced fluorescence detection (CE-LIF). Our results indicated that ACC derivatized with FQ could be well separated from other interfering amino acids using 20 mM borate buffer (pH 9.35) containing 40 mM sodium dodecyl sulfate and 10 mM Brij 35. The linearity of ACC was determined in the range from 0.05 to 5 microM with a correlation of 0.9967. The concentration detection limit for ACC was 10 nM (signal-to-noise = 3). The sensitivity and selectivity of this described method allows the analysis of ACC in crude apple extracts without extra purification and enrichment procedure.
Collapse
Affiliation(s)
- Xin Liu
- Key Laboratory of MOE for Plant Developmental Biology, College of Life Sciences, Wuhan University, Wuhan 430072, PR China
| | | | | | | |
Collapse
|
34
|
Liu X, Ma L, Lin YW, Lu YT. Determination of abscisic acid by capillary electrophoresis with laser-induced fluorescence detection. J Chromatogr A 2004; 1021:209-13. [PMID: 14735990 DOI: 10.1016/j.chroma.2003.09.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A novel method based on capillary electrophoresis coupled to laser-induced fluorescence detection (CE-LIF) was developed for the determination of abscisic acid (ABA), which is an essential phytohormone during plant growth and development. ABA was labeled with 8-aminopyrene-1,3,6-trisulfonate via reductive amination in presence of acetic acid and sodium cyanoborohydride. The derivatization yield was maximized by optimizing several derivatization parameters including derivatization reagent concentration, reaction temperature and time. The conjugate was separated and quantitated by CE-LIF. The linearity of ABA was determined in the range from 0.1 to 10 micromol l(-1) with a correlation of 0.9979. The derivatization limit of detection for ABA was found to be 56 fmol (corresponding to the concentration of 2.8 x 10(-8) mol l(-1)). The detection limit for ABA was 5.5 amol for an injection volume of 5 nl. As a preliminary application, the proposed method was successfully applied to determining trace amount of ABA in the crude extracts of tobacco without extra purification and enrichment procedure and showed a better selectivity and sensitivity than those conventional methods used in determination of ABA.
Collapse
Affiliation(s)
- Xin Liu
- Key Laboratory of MOE for Plant Developmental Biology, College of Life Sciences, Wuhan University, Wuhan 430072, PR China
| | | | | | | |
Collapse
|
35
|
Xie J, Chen X, Zhang J, Liu J, Tian J, Chen X, Hu Z. A novel double coating for microemulsion electrokinetic chromatography with laser-induced fluorescence detection: as tested with amino acid derivatives. J Pharm Biomed Anal 2004; 36:1-8. [PMID: 15351041 DOI: 10.1016/j.jpba.2004.05.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2004] [Revised: 05/12/2004] [Accepted: 05/17/2004] [Indexed: 11/28/2022]
Abstract
A novel double coating (DC) was developed for fast and reproducible microemulsion electrokinetic chromatography (MEEKC), as tested with separation and determination of amino acids using laser-induced fluorescence (LIF) detection after derivatization with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazol. The simple coating is a combination of a removable covalent layer and a dynamic SDS coating. Hexamethyldisilazane was utilized for the covalent layer that can be regenerated on-line. Compared with previous no-coating method, the analysis time was shortened; and the reproducibility of migration times was improved.
Collapse
Affiliation(s)
- Jianping Xie
- Department of Chemistry, Lanzhou University, Lanzhou 730000, PR China
| | | | | | | | | | | | | |
Collapse
|
36
|
Liu X, Ma L, Lu YT. Determination of phosphoamino acids by micellar electrokinetic capillary chromatography with laser-induced fluorescence detection. Anal Chim Acta 2004. [DOI: 10.1016/j.aca.2004.03.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
37
|
Liu X, Yang LX, Lu YT. Determination of biogenic amines by 3-(2-furoyl)quinoline-2-carboxaldehyde and capillary electrophoresis with laser-induced fluorescence detection. J Chromatogr A 2003; 998:213-9. [PMID: 12862385 DOI: 10.1016/s0021-9673(03)00637-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Micellar electrokinetic capillary chromatography with laser-induced fluorescence detection was applied to the determination of biogenic amines including putrescine, histamine, cadaverine, tyramine, tryptamine, 2-phenylethylamine, spermine, and spermidine. A fluorogenic derivatization reagent, 3-(2-furoyl)quinoline-2-carboxaldehyde, was successfully used to fluorescently label these biogenic amines. Different variables that affect derivatization (derivatization reagent concentration, reaction time and temperature) and separation (buffer concentration, addition of organic modifiers and sodium deoxycholate concentration) were studied. The linearities within concentration ranges of up to two orders of magnitudes were achieved for those species with correlation coefficients from 0.9967 to 0.9992. The detection limits (signal to noise = 3) of biogenic amines can reach 5 x 10(-10) mol l(-1), which are equivalent to or better than the detection limits obtained by other analytical methods of biogenic amines. As a preliminary application, this method has been successfully employed to determine biogenic amines in the extract of tobacco leaf.
Collapse
Affiliation(s)
- Xin Liu
- Key Laboratory of MOE for Plant Developmental Biology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | | | | |
Collapse
|
38
|
Jaworska M, Szulińska Z, Wilk M. Development of a capillary electrophoretic method for the analysis of amino acids containing tablets. J Chromatogr A 2003; 993:165-72. [PMID: 12735449 DOI: 10.1016/s0021-9673(03)00394-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Ketosteril is an enteral medicinal product indicated for prevention and therapy in chronic renal insufficiency in connection with a low protein diet. Tablets of Ketosteril contain five essential amino acids like: Lys, His, Thr, Trp, Tyr and another five amino acids in the form of their hydroxy and keto analogues as calcium salts, that are: alpha-ketoleucine, alpha-ketoisoleucine, alpha-ketovaline, alpha-ketophenylalanine and alpha-hydroxymethionine. The composition of Ketosteril tablets is routinely tested with three LC methods. Capillary electrophoretic method seems to be a good alternative for amino acids and their analogues determination in multicomponent pharmaceuticals because of short analysis time and the possibility to assay all components during a single run without any pretreatment. Electrophoresis was performed in 50 microm I.D. fused-silica capillaries with 65 cm distance to the detector. Capillaries were installed in Waters Quanta 4000 electrophoretic equipment with a positive power supply and on-line UV detection at 214 nm. Separations were done in a buffer containing 40 mM Tris and 160 mM boric acid titrated with NaOH to pH 10. The method developed allows the separation of all investigated analytes with an efficiency of n = 230,000 and 20 min analysis time. The method was applied for determination of all components of Ketosteril in commercial tablets.
Collapse
Affiliation(s)
- Małgorzata Jaworska
- Department of Biological Preparations, Drug Institute, Chelmska 30134 Str., 00-725 Warsaw, Poland.
| | | | | |
Collapse
|
39
|
Catecholamines derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole: characterization of chemical structure and fluorescence properties. Anal Chim Acta 2003. [DOI: 10.1016/s0003-2670(02)01515-5] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
40
|
Derivatization Reactions for Analytes with Various Functional Groups. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0301-4770(02)80020-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
41
|
Abstract
The aim of this study was to develop a general approach for characterizing the impurity profile of amino acids at level 0.1% by means of capillary electrophoresis (CE). Checking a variety of labeling reagents revealed 9-fluorenylmethyl chloroformate to be favorable, due to the high stability of its derivatives and the fact that the reagent peaks do not interfere with the peaks of the impurities. After optimization, the method was sufficiently sensitive to evaluate impurities at a 0.1% level by UV detection. The method was representatively validated for phenylalanine (Phe) with regard to selectivity, precision, linearity and accuracy using model mixtures of potential impurities. The CE analyzes method was applied to Phe samples of different manufacturers and the capabilities of the strategy was also demonstrated by samples of tryptophan and serine.
Collapse
Affiliation(s)
- N Novatchev
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074, Wurzburg, Germany
| | | |
Collapse
|
42
|
Liu BF, Zhang L, Lu YT. Characterization of phosphorylation of a novel protein kinase in rice cells by capillary electrophoresis. J Chromatogr A 2001; 918:401-9. [PMID: 11407587 DOI: 10.1016/s0021-9673(01)00741-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
It was demonstrated that a separation of 20 amino acids constituting a protein and three phosphoamino acids that mostly frequently occur in eukaryotes was achieved within 15 min by capillary electrophoresis coupled with lamp-induced fluorescence detection. Fluorescein isothiocyanate was employed as the fluorescence label to facilitate the fluorescence detection of the 23 amino acid species. The fluorescent derivatization conditions and separation parameters including concentration of electrolyte, surfactant in buffer, applied voltage and sample injection were investigated in detail and optimized. The influence of buffer additives such as methanol, acetone and polyvinylpyrrolidone on separation selectivity and sensitivity were discussed. We showed that addition of 2% polyvinylpyrrolidone into the running buffer could dramatically enhance the separation selectivity of amino acids at the expense of a decrease of sensitivity of phosphoamino acids. Under the optimized conditions, the detection limits (S/N=2) ranged from 1.90 x 10(-8) M to 5.66 x 10(-8) M with an average efficiency of 620,000/m. The method was applied to characterization of the phosphorylation of a novel protein kinase RCaMBP (calcium/calmodulin-binding protein kinase) encoded by a cDNA newly isolated and cloned from rice. We verified that RCaMBP belonged to a type of Ser/Thr kinase, providing insight into its function in signal transduction.
Collapse
Affiliation(s)
- B F Liu
- Key Laboratory of MOE for Plant Developmental Biology, Wuhan University, China
| | | | | |
Collapse
|