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Scriba GKE. Update on chiral recognition mechanisms in separation science. J Sep Sci 2024; 47:e2400148. [PMID: 38772711 DOI: 10.1002/jssc.202400148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Revised: 04/04/2024] [Accepted: 04/12/2024] [Indexed: 05/23/2024]
Abstract
The stereospecific analysis of chiral molecules is an important issue in many scientific fields. In separation sciences, this is achieved via the formation of transient diastereomeric complexes between a chiral selector and the selectand enantiomers driven by molecular interactions including electrostatic, ion-dipole, dipole-dipole, van der Waals or π-π interactions as well as hydrogen or halogen bonds depending on the nature of selector and selectand. Nuclear magnetic resonance spectroscopy and molecular modeling methods are currently the most frequently applied techniques to understand the selector-selectand interactions at a molecular level and to draw conclusions on the chiral separation mechanism. The present short review summarizes some of the recent achievements for the understanding of the chiral recognition of the most important chiral selectors combining separation techniques with molecular modeling and/or spectroscopic techniques dating between 2020 and early 2024. The selectors include polysaccharide derivatives, cyclodextrins, macrocyclic glycopeptides, proteins, donor-acceptor type selectors, ion-exchangers, crown ethers, and molecular micelles. The application of chiral ionic liquids and chiral deep eutectic solvents, as well as further selectors, are also briefly addressed. A compilation of all published literature on chiral selectors has not been attempted.
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Affiliation(s)
- Gerhard K E Scriba
- Department of Pharmaceutical/Medicinal Chemistry, Friedrich Schiller University, Jena, Germany
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Modroiu A, Krait S, Hancu G, Scriba GKE. Quality by design-guided development of a capillary electrophoresis method for the simultaneous chiral purity determination and impurity profiling of tamsulosin. J Sep Sci 2023; 46:e2300604. [PMID: 37937344 DOI: 10.1002/jssc.202300604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 10/13/2023] [Accepted: 10/17/2023] [Indexed: 11/09/2023]
Abstract
Analytical Quality by Design principles using the design of experiments were applied for the development of a capillary electrophoresis method for the determination of enantiomeric purity and chemically related impurities of tamsulosin. From initial scouting experiments, a dual cyclodextrin (CD) system composed of sulfated β-CD and carboxymethyl-α-CD was selected as the chiral selector. A fractional factorial resolution V+ design was used for the identification of the critical process parameters, while a face-centered central composite design and Monte Carlo simulations were employed for final optimization and defining the design space of the method. The experimental conditions of the working point were: 30 mM sodium phosphate buffer, pH 3.0, containing 40 mg/mL sulfated β-CD and 7 mg/mL carboxymethyl-α-CD, capillary temperature 18°C, applied voltage -23 kV. Following the assessment of robustness by applying a Plackett-Burman design, the method was validated according to the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use guideline Q2(R1). The method allowed the quantification of the chiral impurity and three other related impurities at the 0.1 % level with acceptable accuracy and precision.
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Affiliation(s)
- Adriana Modroiu
- Department of Pharmaceutical/Medicinal Chemistry, Friedrich Schiller University, Jena, Germany
- Department of Pharmaceutical and Therapeutic Chemistry, Faculty of Pharmacy, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Targu Mures, Targu Mures, Romania
| | - Sulaiman Krait
- Department of Pharmaceutical/Medicinal Chemistry, Friedrich Schiller University, Jena, Germany
| | - Gabriel Hancu
- Department of Pharmaceutical and Therapeutic Chemistry, Faculty of Pharmacy, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Targu Mures, Targu Mures, Romania
| | - Gerhard K E Scriba
- Department of Pharmaceutical/Medicinal Chemistry, Friedrich Schiller University, Jena, Germany
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Modroiu A, Krait S, Hancu G, Scriba GKE. Quality by design-guided development of a capillary electrophoresis method for the chiral purity determination of silodosin. J Pharm Biomed Anal 2023; 222:115117. [PMID: 36306637 DOI: 10.1016/j.jpba.2022.115117] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/16/2022] [Accepted: 10/17/2022] [Indexed: 06/16/2023]
Abstract
Silodosin is a single isomer selective α1-adrenoreceptor antagonist used for the treatment of benign prostatic hyperplasia. In order to control the enantiomeric purity of the drug a capillary electrophoresis method was developed that is applicable to the analysis of drug substance as well as pharmaceutical formulations. Method development followed a quality by design strategy. After selection of carboxymethyl-β-cyclodextrin as suitable chiral selector and the starting conditions in the scouting phase, a two-level full factorial design was applied to identify the critical process parameters. The final method optimization was performed using a face-centered central composite design resulting in the conditions 100 mM sodium phosphate buffer, pH 2.9, containing 40 mg/mL car-boxymethyl-β-cyclodextrin, a capillary temperature of 17 °C and an applied voltage of 28 kV. Robustness testing employing a Plackett-Burman design revealed the importance of careful pH adjustment in order to achieve suitable peak shape and resolution. The method was validated according to the guideline Q2(R1) of the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use and applied to the analysis of a commercial capsule formulation.
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Affiliation(s)
- Adriana Modroiu
- Friedrich Schiller University, Department of Pharmaceutical/Medicinal Chemistry, Philosophenweg 14, D-07743 Jena, Germany; George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, Department of Pharmaceutical and Therapeutic Chemistry, Faculty of Pharmacy, Gh. Marinescu 38, 540142 Târgu Mureș, Romania
| | - Sulaiman Krait
- Friedrich Schiller University, Department of Pharmaceutical/Medicinal Chemistry, Philosophenweg 14, D-07743 Jena, Germany
| | - Gabriel Hancu
- George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, Department of Pharmaceutical and Therapeutic Chemistry, Faculty of Pharmacy, Gh. Marinescu 38, 540142 Târgu Mureș, Romania
| | - Gerhard K E Scriba
- Friedrich Schiller University, Department of Pharmaceutical/Medicinal Chemistry, Philosophenweg 14, D-07743 Jena, Germany.
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Krait S, Schneidmadel FR, Scriba GKE. Quality by design‐assisted development of a capillary electrophoresis method for the enantiomeric purity determination of tenofovir. Electrophoresis 2022; 43:964-969. [DOI: 10.1002/elps.202100345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 11/09/2022]
Affiliation(s)
- Sulaiman Krait
- Department of Pharmaceutical/Medicinal Chemistry Friedrich Schiller University Jena Germany
| | - Felix R. Schneidmadel
- Department of Pharmaceutical/Medicinal Chemistry Friedrich Schiller University Jena Germany
| | - Gerhard K. E. Scriba
- Department of Pharmaceutical/Medicinal Chemistry Friedrich Schiller University Jena Germany
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Krait S, Salgado A, Malanga M, Sohajda T, Benkovics G, Szakály PS, Chankvetadze B, Scriba GKE. Structural characterization of methyl-β-cyclodextrins by high-performance liquid chromatography and nuclear magnetic resonance spectroscopy and effect of their isomeric composition on the capillary electrophoresis enantioseparation of daclatasvir. J Chromatogr A 2021; 1661:462675. [PMID: 34890854 DOI: 10.1016/j.chroma.2021.462675] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 10/20/2021] [Accepted: 11/04/2021] [Indexed: 10/19/2022]
Abstract
The separation of daclatasvir and its R,R,R,R-enantiomer was studied by capillary electrophoresis using various randomly methylated β-CDs and the single isomer heptakis(2,6-di-O-methyl)-β-CD (2,6-DM-β-CD) as chiral selectors in an acidic background electrolyte. Opposite enantiomer migration order was observed for randomly substituted CDs compared to 2,6-DM-β-CD as well as methylated β-CDs with different composition according to the specifications of the manufacturers. HPLC and NMR analyses confirmed that the presence of a high 2,6-DM-β-CD content in the CDs enables to achieve the migration order R,R,R,R-enantiomer > daclatasvir. In contrast, products with low 2,6-DM-β-CD isomer content and/or the presence of a large amount of methylated CD isomers, in which d-glucopyranose moieties are not substituted in either position 2 or 6, displayed the opposite enantiomer migration order daclatasvir > R,R,R,R-enantiomer. The study indicated the importance of the type and composition of derivatized CDs on chiral separations in capillary electrophoresis as well as the importance of proper quality control for cyclodextrin manufacturers. Moreover, the observed migration order could be rationalized based on the composition and substitution pattern of the CDs.
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Affiliation(s)
- Sulaiman Krait
- Department of Pharmaceutical/Medicinal Chemistry, Friedrich-Schiller-University Jena, Philosophenweg 14, Jena 07743, Germany
| | - Antonio Salgado
- NMR Spectroscopy Center (CERMN), CAI Químicas, Faculty of Pharmacy, University of Alcalá, Madrid, Alcalá de Henares 28805, Spain
| | - Milo Malanga
- CycloLab Ltd., Illatos út 7, Budapest 1097, Hungary
| | | | | | | | - Bezhan Chankvetadze
- Institute of Physical and Analytical Chemistry, School of Exact and Natural Sciences, Tbilisi State University, Tbilisi 0179, Georgia
| | - Gerhard K E Scriba
- Department of Pharmaceutical/Medicinal Chemistry, Friedrich-Schiller-University Jena, Philosophenweg 14, Jena 07743, Germany.
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Hartmann M, Bibli SI, Tews D, Ni X, Kircher T, Kramer JS, Kilu W, Heering J, Hernandez-Olmos V, Weizel L, Scriba GKE, Krait S, Knapp S, Chaikuad A, Merk D, Fleming I, Fischer-Posovszky P, Proschak E. Combined Cardioprotective and Adipocyte Browning Effects Promoted by the Eutomer of Dual sEH/PPARγ Modulator. J Med Chem 2021; 64:2815-2828. [PMID: 33620196 DOI: 10.1021/acs.jmedchem.0c02063] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The metabolic syndrome (MetS) is a constellation of cardiovascular and metabolic symptoms involving insulin resistance, steatohepatitis, obesity, hypertension, and heart disease, and patients suffering from MetS often require polypharmaceutical treatment. PPARγ agonists are highly effective oral antidiabetics with great potential in MetS, which promote adipocyte browning and insulin sensitization. However, the application of PPARγ agonists in clinics is restricted by potential cardiovascular adverse events. We have previously demonstrated that the racemic dual sEH/PPARγ modulator RB394 (3) simultaneously improves all risk factors of MetS in vivo. In this study, we identify and characterize the eutomer of 3. We provide structural rationale for molecular recognition of the eutomer. Furthermore, we could show that the dual sEH/PPARγ modulator is able to promote adipocyte browning and simultaneously exhibits cardioprotective activity which underlines its exciting potential in treatment of MetS.
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Affiliation(s)
- Markus Hartmann
- Institute of Pharmaceutical Chemistry, Goethe University, Max-von-Laue-Strasse 9, D-60438 Frankfurt am Main, Germany
| | - Sofia-Iris Bibli
- Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University, D-60596 Frankfurt am Main, Germany
| | - Daniel Tews
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Centre, D-89075 Ulm, Germany
| | - Xiaomin Ni
- Institute of Pharmaceutical Chemistry, Goethe University, Max-von-Laue-Strasse 9, D-60438 Frankfurt am Main, Germany
| | - Theresa Kircher
- Institute of Pharmaceutical Chemistry, Goethe University, Max-von-Laue-Strasse 9, D-60438 Frankfurt am Main, Germany
| | - Jan S Kramer
- Institute of Pharmaceutical Chemistry, Goethe University, Max-von-Laue-Strasse 9, D-60438 Frankfurt am Main, Germany
| | - Whitney Kilu
- Institute of Pharmaceutical Chemistry, Goethe University, Max-von-Laue-Strasse 9, D-60438 Frankfurt am Main, Germany
| | - Jan Heering
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Theodor-Stern-Kai 7, D-60596 Frankfurt, Germany
| | - Victor Hernandez-Olmos
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Theodor-Stern-Kai 7, D-60596 Frankfurt, Germany
| | - Lilia Weizel
- Institute of Pharmaceutical Chemistry, Goethe University, Max-von-Laue-Strasse 9, D-60438 Frankfurt am Main, Germany
| | - Gerhard K E Scriba
- Department of Pharmaceutical/Medicinal Chemistry, Friedrich Schiller University Jena, Philosophenweg 14, D-07743 Jena, Germany
| | - Sulaiman Krait
- Department of Pharmaceutical/Medicinal Chemistry, Friedrich Schiller University Jena, Philosophenweg 14, D-07743 Jena, Germany
| | - Stefan Knapp
- Institute of Pharmaceutical Chemistry, Goethe University, Max-von-Laue-Strasse 9, D-60438 Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max-von-Laue-Strasse 15, D-60438 Frankfurt, Germany
| | - Apirat Chaikuad
- Institute of Pharmaceutical Chemistry, Goethe University, Max-von-Laue-Strasse 9, D-60438 Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max-von-Laue-Strasse 15, D-60438 Frankfurt, Germany
| | - Daniel Merk
- Institute of Pharmaceutical Chemistry, Goethe University, Max-von-Laue-Strasse 9, D-60438 Frankfurt am Main, Germany
| | - Ingrid Fleming
- Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University, D-60596 Frankfurt am Main, Germany
| | - Pamela Fischer-Posovszky
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Centre, D-89075 Ulm, Germany
| | - Ewgenij Proschak
- Institute of Pharmaceutical Chemistry, Goethe University, Max-von-Laue-Strasse 9, D-60438 Frankfurt am Main, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Theodor-Stern-Kai 7, D-60596 Frankfurt, Germany
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Krait S, Wissenbach DK, Peters FT, Scriba GKE. HPLC-MS identification of acid degradation products of dolutegravir. J Pharm Biomed Anal 2021; 197:113954. [PMID: 33601161 DOI: 10.1016/j.jpba.2021.113954] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 02/01/2021] [Accepted: 02/01/2021] [Indexed: 11/28/2022]
Abstract
Dolutegravir is an integrase strand transfer inhibitor used for the treatment of human immuno-deficiency virus infections. The present study was conducted in order to identify degradation products formed in acidic solution upon heating. The structures were assigned based on low resolution collision-induced dissociation tandem mass spectra as well as high resolution higher-energy collisional dissociation tandem mass spectra. The major degradation products resulted from hydrolytic opening of the oxepine ring leading to bis-hydroxy diastereomers (DP2 and DP3) as well as a mono-hydroxy derivative (DP1) as the result of dehydration of the diastereomers. Furthermore, two carboxylic acid derivatives (DP4 and DP5) could be identified, which can be explained as the result of the hydrolysis of the exocyclic amide bond of dolutegravir and DP1, respectively. During the fragmentation process of dolutegravir and its degradation products DP1 to DP3 a formal addition of oxygen resulting in the respective carboxylic acid fragments was detected. This could be evidenced based on high resolution masses of the fragments as well as the comparison of the MS/MS spectra of the fragments with the spectra of the carboxylic acids DP4 and DP5.
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Affiliation(s)
- Sulaiman Krait
- Friedrich Schiller University, Department of Pharmaceutical/Medicinal Chemistry, Philosophenweg 14, D-07743 Jena, Germany
| | - Dirk K Wissenbach
- Institute of Forensic Medicine, Jena University Hospital, 07740 Jena, Germany
| | - Frank T Peters
- Institute of Forensic Medicine, Jena University Hospital, 07740 Jena, Germany
| | - Gerhard K E Scriba
- Friedrich Schiller University, Department of Pharmaceutical/Medicinal Chemistry, Philosophenweg 14, D-07743 Jena, Germany.
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Krait S, Konjaria ML, Scriba GKE. Advances of capillary electrophoresis enantioseparations in pharmaceutical analysis (2017-2020). Electrophoresis 2021; 42:1709-1725. [PMID: 33433919 DOI: 10.1002/elps.202000359] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/04/2021] [Accepted: 01/04/2021] [Indexed: 02/06/2023]
Abstract
Capillary electrophoresis is a powerful technique for the analysis of polar chiral compounds and has been widely accepted for analytical enantioseparations of drug compounds in pharmaceuticals and biological media. In addition, many mechanistic studies have been conducted in an attempt to rationalize enantioseparations in combination with spectroscopic and computational techniques. The present review will focus on recent examples of mechanistic aspects and summarize recent applications of stereoselective pharmaceutical and biomedical analysis published between January 2017 and November 2020. Various separation modes including electrokinetic chromatography in combination with several detection modes including laser-induced fluorescence, mass spectrometry and contactless conductivity detection will be discussed. A general trend also observed in other analytical techniques is the application of quality by design principles in method development and optimization.
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Affiliation(s)
- Sulaiman Krait
- Department of Pharmaceutical/Medicinal Chemistry, Philosophenweg 14, Friedrich Schiller University, Jena, Germany
| | - Mari-Luiza Konjaria
- Department of Pharmaceutical/Medicinal Chemistry, Philosophenweg 14, Friedrich Schiller University, Jena, Germany
| | - Gerhard K E Scriba
- Department of Pharmaceutical/Medicinal Chemistry, Philosophenweg 14, Friedrich Schiller University, Jena, Germany
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Niedermeier S, Scriba GKE. Chiral separation of four phenothiazines by nonaqueous capillary electrophoresis and quality by design-based method development for quantification of dextromepromazine as chiral impurity of levomepromazine. J Chromatogr A 2020; 1624:461232. [PMID: 32540073 DOI: 10.1016/j.chroma.2020.461232] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 05/08/2020] [Accepted: 05/10/2020] [Indexed: 11/18/2022]
Abstract
The separation of the enantiomers of mepromazine, promethazine, thioridazine and alimemazine was studied by nonaqueous capillary electrophoresis in the presence of cyclodextrins using 1 M acetic acid and 50 mM ammonium acetate in methanol as background electrolyte. Heptakis(2,3-di-O-acetyl-6-O-sulfo)-β-cyclodextrin, heptakis(2,3-di-O-methyl-6-O-sulfo)-β-cyclodextrin (HDMS-β-CD) and octakis(2,3-di-O-methyl-6-O-sulfo)-γ-cyclodextrin were the most effective chiral selectors for mepromazine, promethazine and alimemazine. Subsequently, a method for the determination of dextromepromazine as chiral impurity of levomepromazine was developed employing quality by design principles. Using HDMS-β-CD as selector, a fractional factorial resolution V+ design was employed for evaluating the knowledge space, while a central composite face centered design provided further method optimization and the basis for the computation of the design space by Monte Carlo simulations. The final experimental conditions included a 30/40.2 cm fused-silica capillary with 75 µm inner diameter and a background electrolyte composed of 0.75 M acetic acid and 55 mM ammonium acetate in methanol containing 27.5 mg/mL HDMS-β-CD. The applied voltage was 22 kV and the capillary temperature was 15°C. Following method robustness testing via a Plackett-Burman design, the method was validated for dextromepromazine in the range of 0.01 to 3.0 % relative to a concentration of 0.74 mg/mL levomepromazine and applied to the analysis of reference standards of the European Pharmacopoeia and commercial tablets. The assay also allowed the detection of levomepromazine sulfoxide although the quantitation of the compound was hampered by the poor peak shape of the late migrating diastereomer.
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Affiliation(s)
- Stephan Niedermeier
- Department of Pharmaceutical and Medicinal Chemistry, Friedrich Schiller University Jena, Philosophenweg 14, 07743 Jena, Germany
| | - Gerhard K E Scriba
- Department of Pharmaceutical and Medicinal Chemistry, Friedrich Schiller University Jena, Philosophenweg 14, 07743 Jena, Germany.
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Harnisch H, Ilisz I, Fülöp F, Szakonyi Z, Kiss L, Péter A, Scriba GKE. Cyclodextrin-mediated capillary electrophoresis enantioseparation of dansylated β-amino acids with bicyclo[2.2.2]octane, bicyclo[3.1.1]heptane and cyclopenta[d][1,2]oxazole core structures. Electrophoresis 2019; 40:1931-1940. [DOI: 10.1002/elps.201800492] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/28/2019] [Accepted: 01/30/2019] [Indexed: 11/06/2022]
Affiliation(s)
- Henrik Harnisch
- Department of Pharmaceutical and Medicinal Chemistry; School of Pharmacy; Friedrich Schiller University Jena; Jena Germany
| | - István Ilisz
- Institute of Pharmaceutical Analysis; Interdisciplinary Excellence Centre; University of Szeged; Szeged Hungary
| | - Ferenc Fülöp
- Institute of Pharmaceutical Chemistry; Interdisciplinary Excellence Centre; University of Szeged; Szeged Hungary
| | - Zsolt Szakonyi
- Institute of Pharmaceutical Chemistry; Interdisciplinary Excellence Centre; University of Szeged; Szeged Hungary
| | - Lóránd Kiss
- Institute of Pharmaceutical Chemistry; Interdisciplinary Excellence Centre; University of Szeged; Szeged Hungary
| | - Antal Péter
- Institute of Pharmaceutical Analysis; Interdisciplinary Excellence Centre; University of Szeged; Szeged Hungary
| | - Gerhard K. E. Scriba
- Department of Pharmaceutical and Medicinal Chemistry; School of Pharmacy; Friedrich Schiller University Jena; Jena Germany
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Abstract
Stereospecific recognition of chiral molecules plays an important role in nature as the basis of the interaction of chiral bioactive compounds with the chiral target structures. In separation sciences such as chromatographic and capillary electromigration techniques, interactions between chiral analytes and chiral selectors, i.e., the formation of transient diastereomeric complexes in thermodynamic equilibria, are the basis for chiral separations. Due to the large structural variety of chiral selectors, different structural features contribute to the overall chiral recognition process. This introductory chapter briefly summarizes the present understanding of the structural enantioselective recognition processes for various types of chiral selectors.
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Affiliation(s)
- Gerhard K E Scriba
- Department of Pharmaceutical Chemistry, University of Jena, Jena, Germany.
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Knoth H, Scriba GKE, Langnaese S, Buettner B. Differential pulse polarographic investigation of micafungin and anidulafungin using a dropping mercury electrode. Pharmazie 2019; 74:18-22. [PMID: 30782245 DOI: 10.1691/ph.2019.8680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 09/29/2022]
Abstract
The electrochemical behavior of the echinocandin antifungals anidulafungin (AF) and micafungin (MF) has been investigated by differential pulse polarography (DPP). The measurements were carried out in a supporting electrolyte solution consisting of Britton-Robinson buffer and methanol at various substance concentrations and pH values. An amperometric cell with a three electrode system consisting of a dropping mercury electrode (DME) as working electrode, an auxiliary platinum electrode and an Ag/AgCl reference electrode was used in all experiments. AF was electrochemically reduced at potentials between -1.3 and -1.5 V. MF showed a first reduction peak (a) between -1.0 and -1.4 V and a second peak (b) between -1.5 and -1.8 V. A strong pH-dependence was observed, with optimal results at pH 2.0-3.0 for the AF peak, pH 2.0 for the MF peak (a) and pH 5.0 for the MF peak (b). A linear correlation between the concentration and the peak current has been demonstrated for all reduction peaks. MF peak (a) showed a similar behavior to the AF peak regarding shape, peak current and pH-dependence. Therefore, it can be assumed that both reductions are based on the same mechanism, a two-step reduction of the N-acyl group.
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Abstract
Due to their structural variability and their commercial availability, cyclodextrins are the most frequently used chiral selectors in capillary electrophoresis. A variety of migration modes can be realized depending on the characteristics of the cyclodextrins and the analytes. The basic considerations regarding the development of a chiral CE method employing cyclodextrins as chiral selectors are briefly discussed. The presented examples illustrate the separation modes of an acidic and a basic analyte with native and charged cyclodextrin derivatives as a function of the pH of the background electrolyte and the concentration of the cyclodextrin.
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Affiliation(s)
- Gerhard K E Scriba
- Department of Pharmaceutical Chemistry, University of Jena, Jena, Germany
| | - Pavel Jáč
- Faculty of Pharmacy in Hradec Králové, Department of Analytical Chemistry, Charles University, Hradec Králové, Czech Republic.
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Chen C, Bönisch D, Penzis R, Winckler T, Scriba GKE. Capillary Electrophoresis-Based Enzyme Assay for Nicotinamide N-Methyltransferase. Chromatographia 2018. [DOI: 10.1007/s10337-018-3594-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Harnisch H, Scriba GKE. Capillary electrophoresis method for the determination of (R)-dapoxetine, (3S)-3-(dimethylamino)-3-phenyl-1-propanol, (S)-3-amino-3-phenyl-1-propanol and 1-naphthol as impurities of dapoxetine hydrochloride. J Pharm Biomed Anal 2018; 162:257-263. [PMID: 30273816 DOI: 10.1016/j.jpba.2018.09.039] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 09/18/2018] [Accepted: 09/18/2018] [Indexed: 01/15/2023]
Abstract
A capillary electrophoresis method was developed and validated for the determination of the purity of dapoxetine with regard to the related substances (3S)-3-amino-3-phenylpropan-1-ol, (3S)-3-(dimethylamino)-3-phenylpropan-1-ol, 1-naphthol and the enantiomer (R)-dapoxetine. The separation was based on a dual selector system, which was optimized by a fractional factorial resolution V + design followed by a central composite face centered design with star distance 1 and Monte Carlo simulations for defining the design space. The optimized background electrolyte consisted of a 50 mM sodium phosphate buffer, pH 6.3, containing 45 mg/mL sulfated γ-cyclodextrin and 40.2 mg/mL 2,6-dimethyl-β-cyclodextrin. Separations were carried out in a 23.5/32 cm, 50 μm fused-silica capillary employing a separation voltage of 9 kV at 15 °C. Following robustness testing using a Plackett-Burman design the method was validated according to the International Council on Harmonization guideline Q2(R1) in the range of 0.05-1.0% relative to the dapoxetine concentration. The method was applied to the analysis of drug substance and a commercial tablet. Data regarding the enantiomeric purity of dapoxetine obtained by the capillary electrophoresis assay were comparable to the data obtained by an enantioselective HPLC method.
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Affiliation(s)
- Henrik Harnisch
- Department of Pharmaceutical and Medicinal Chemistry, School of Pharmacy, Friedrich Schiller University Jena, Philosophenweg 14, 07743 Jena, Germany
| | - Gerhard K E Scriba
- Department of Pharmaceutical and Medicinal Chemistry, School of Pharmacy, Friedrich Schiller University Jena, Philosophenweg 14, 07743 Jena, Germany.
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Krait S, Salgado A, Chankvetadze B, Gago F, Scriba GKE. Investigation of the complexation between cyclodextrins and medetomidine enantiomers by capillary electrophoresis, NMR spectroscopy and molecular modeling. J Chromatogr A 2018; 1567:198-210. [PMID: 30055912 DOI: 10.1016/j.chroma.2018.06.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/30/2018] [Accepted: 06/05/2018] [Indexed: 12/12/2022]
Abstract
The migration order of the enantiomers of medetomidine in the presence of cyclodextrins studied by capillary electrophoresis in phosphate buffer, pH 2.5, depended on the cavity size and the substitution pattern of the cyclodextrins. Opposite migration order was observed in the presence of β-cyclodextrin (β-CD) and γ-cyclodextrin (γ-CD) as well as randomly sulfated β-CD (S-β-CD) and heptakis(6-O-sulfo)-β-CD (HS-β-CD). This could be rationalized by the fact that dexmedetomidine formed more stable complexes with β-CD and S-β-CD, while levomedetomidine interacted stronger with γ-CD and HS-β-CD. The structure of the complexes was derived from rotating frame nuclear Overhauser (ROESY) experiments for β-CD, γ-CD and HS-β-CD. In the case of the native CDs, the phenyl ring of medetomidine entered the cavity through the wider secondary rim of the CDs, whereas the protonated imidazole ring was positioned inside the CD cavity interacting with the sulfate groups of HS-β-CD. Furthermore, molecular dynamics calculations also suggested opposite affinities of the medetomidine enantiomers toward β-CD and γ-CD.
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Affiliation(s)
- Sulaiman Krait
- Friedrich-Schiller-University Jena, Department of Pharmaceutical/Medicinal Chemistry, Philosophenweg 14, 07743 Jena, Germany
| | - Antonio Salgado
- University of Alcalá, NMR Spectroscopy Centre (CERMN), CAI Químicas, Faculty of Pharmacy, 28805 Alcalá de Henares, Madrid, Spain
| | - Bezhan Chankvetadze
- Tbilisi State University, Institute of Physical and Analytical Chemistry, School of Exact and Natural Sciences, 0179 Tbilisi, Georgia
| | - Federico Gago
- University of Alcalá, Department of Biomedical Sciences (Unidad Asociada IQM-CSIC) and Instituto de Investigación Química "Andrés M. del Río" (IQAR), 28805 Alcalá de Henares, Madrid, Spain
| | - Gerhard K E Scriba
- Friedrich-Schiller-University Jena, Department of Pharmaceutical/Medicinal Chemistry, Philosophenweg 14, 07743 Jena, Germany.
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Krait S, Scriba GKE. Quality by design-assisted development of a capillary electrophoresis method for the chiral purity determination of dexmedetomidine. Electrophoresis 2018; 39:2575-2580. [PMID: 29600596 DOI: 10.1002/elps.201800100] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 03/07/2018] [Accepted: 03/07/2018] [Indexed: 12/29/2022]
Abstract
Dexmedetomidine is a selective α2 -adrenergic agonist used for patient sedation, while its enantiomer levomedetomidine has no sedative effects. As CE has been shown to be a powerful technique for enantiomer analysis, the aim of the study was the quality by design-based development of a CE-based limit test for the enantiomeric impurity levomedetomidine. The analytical target profile was defined that the method should be able to determine levomedetomidine with acceptable precision and accuracy at the 0.1% level. From initial scouting experiments, sulfated β-cyclodextrin was selected as chiral selector. The critical process parameters were identified in a fractional factorial resolution V+ design, while a central composite face centered design and Monte Carlo simulations were used for defining the design space of the method. The selected working conditions were a 21.3/31.5 cm, 50 μm id fused-silica capillary, a 50 mM sodium phosphate buffer, pH 6.5, containing 40 mg/mL sulfated β-cyclodextrin, a capillary temperature of 17°C and an applied voltage of 10 kV. Validation according to the ICH guideline Q2(R1) demonstrated repeatability and intermediate precision of content and migration time between 9.3 and 4.2% with accuracy in the range of 92.0 and 98.9%.
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Affiliation(s)
- Sulaiman Krait
- Friedrich Schiller University, Department of Medicinal/Pharmaceutical Chemistry, Jena, Germany
| | - Gerhard K E Scriba
- Friedrich Schiller University, Department of Medicinal/Pharmaceutical Chemistry, Jena, Germany
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Harnisch H, Chien YH, Scriba GKE. Capillary Electrophoresis Method for the Chiral Purity Determination of Pregabalin Derivatized with Dansyl Chloride. Chromatographia 2018. [DOI: 10.1007/s10337-018-3495-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Krait S, Heuermann M, Scriba GKE. Development of a capillary electrophoresis method for the determination of the chiral purity of dextromethorphan by a dual selector system using quality by design methodology. J Sep Sci 2018; 41:1405-1413. [PMID: 29131506 DOI: 10.1002/jssc.201701166] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 11/04/2017] [Accepted: 11/04/2017] [Indexed: 11/08/2022]
Abstract
Dextromethorphan is a centrally acting antitussive drug, while its enantiomer levomethorphan is an illicit drug with opioid analgesic effects. As capillary electrophoresis has been proven as an ideal technique for enantiomer analysis, the present study was conducted in order to develop a capillary electrophoresis-based limit test for levomethorphan. The analytical target profile was defined as a method that should be able to determine levomethorphan with acceptable precision and accuracy at the 0.1 % level. From initial scouting experiments, a dual selector system consisting of sulfated β-cyclodextrin and methyl-α-cyclodextrin was identified. The critical process parameters were evaluated in a fractional factorial resolution IV design followed by a central composite face-centered design and Monte Carlo simulations for defining the design space of the method. The selected working conditions consisted of a 30/40.2 cm, 50 μm id fused-silica capillary, 30 mM sodium phosphate buffer, pH 6.5, 16 mg/mL sulfated β-cyclodextrin, and 14 mg/mL methyl-α-cyclodextrin at 20°C and 20 kV. The method was validated according to ICH guideline Q2(R1) and applied to the analysis of a capsule formulation. Furthermore, the apparent binding constants between the enantiomers and the cyclodextrins as well as complex mobilities were determined to understand the migration behavior of the analytes.
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Affiliation(s)
- Sulaiman Krait
- Department of Pharmaceutical Chemistry, Friedrich Schiller University, Jena, Germany
| | | | - Gerhard K E Scriba
- Department of Pharmaceutical Chemistry, Friedrich Schiller University, Jena, Germany
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Affiliation(s)
- Debby Mangelings
- Department of Analytical Chemistry and Pharmaceutical Technology, Center for Pharmaceutical Research, Vrije Universiteit Brussel, Brussels, Belgium
| | | | - Brett Paull
- Australian Centre for Research on Separation Sciences (ACROSS), School of Physical Sciences, University of Tasmania, Hobart, Australia
| | - Gerhard K. E. Scriba
- Department of Pharmaceutical/Medicinal Chemistry, Friedrich Schiller University Jena, Jena, Germany
| | - Roger M. Smith
- Department of Chemistry, Loughborough University, Loughborough, UK
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Harnisch H, Hühner J, Neusüß C, Koschella A, Heinze T, Scriba GKE. Development and validation of a capillary electrophoresis method for the characterization of sulfoethyl cellulose. J Sep Sci 2016; 39:4645-4652. [PMID: 27696722 DOI: 10.1002/jssc.201600687] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 09/22/2016] [Accepted: 09/24/2016] [Indexed: 11/09/2022]
Abstract
To characterize sulfoethyl cellulose el samples, a capillary electrophoresis method was developed and validated sulfoethyl cellulose el was hydrolyzed, and the resulting d-glucose derivatives were analyzed after reductive amination with 4-aminobenzoic acid using 150 mM boric acid, pH 9.5, as background electrolyte at 20°C and a voltage of 28 kV. Peak identification was derived from capillary electrophoresis with mass spectrometry using 25 mM ammonia adjusted to pH 6.2 by acetic acid as electrolyte. Besides mono-, di-, and trisulfoethyl d-glucose small amounts of disaccharides could be identified resulting from incomplete hydrolysis. The linearity of the borate buffer-based capillary electrophoresis method was evaluated using d-glucose in the concentration range of 3.9-97.5 μg/mL, while limits of detection and quantification derived from the signal-to-noise ratio of 3 and 10 were 0.4 ± 0.1 and 1.2 ± 0.3 μg/mL, respectively. Reproducibility and intermediate precision were determined using a hydrolyzed sulfoethyl cellulose el sample and ranged between 0.2 and 8.8% for migration times and between 0.3 and 10.4% for peak area. The method was applied to the analysis of the degree of substitution of synthetic sulfoethyl cellulose el samples obtained by variation of the synthetic process and compared to data obtained by elemental analysis.
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Affiliation(s)
- Henrik Harnisch
- Department of Pharmaceutical and Medicinal Chemistry, School of Pharmacy, Friedrich Schiller University Jena, Jena, Germany
| | - Jens Hühner
- Faculty of Chemistry, Aalen University, Aalen, Germany.,Institute of Pharmaceutical Science, University of Tübingen, Tübingen, Germany
| | | | - Andreas Koschella
- Center of Excellence for Polysaccharide Research, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University Jena, Jena, Germany
| | - Thomas Heinze
- Center of Excellence for Polysaccharide Research, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University Jena, Jena, Germany
| | - Gerhard K E Scriba
- Department of Pharmaceutical and Medicinal Chemistry, School of Pharmacy, Friedrich Schiller University Jena, Jena, Germany
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Garscha U, Voelker S, Pace S, Gerstmeier J, Emini B, Liening S, Rossi A, Weinigel C, Rummler S, Schubert US, Scriba GKE, Çelikoğlu E, Çalışkan B, Banoglu E, Sautebin L, Werz O. BRP-187: A potent inhibitor of leukotriene biosynthesis that acts through impeding the dynamic 5-lipoxygenase/5-lipoxygenase-activating protein (FLAP) complex assembly. Biochem Pharmacol 2016; 119:17-26. [PMID: 27592027 DOI: 10.1016/j.bcp.2016.08.023] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Accepted: 08/29/2016] [Indexed: 11/19/2022]
Abstract
The pro-inflammatory leukotrienes (LTs) are formed from arachidonic acid (AA) in activated leukocytes, where 5-lipoxygenase (5-LO) translocates to the nuclear envelope to assemble a functional complex with the integral nuclear membrane protein 5-LO-activating protein (FLAP). FLAP, a MAPEG family member, facilitates AA transfer to 5-LO for efficient conversion, and LT biosynthesis critically depends on FLAP. Here we show that the novel LT biosynthesis inhibitor BRP-187 prevents the 5-LO/FLAP interaction at the nuclear envelope of human leukocytes without blocking 5-LO nuclear redistribution. BRP-187 inhibited 5-LO product formation in human monocytes and polymorphonuclear leukocytes stimulated by lipopolysaccharide plus N-formyl-methionyl-leucyl-phenylalanine (IC50=7-10nM), and upon activation by ionophore A23187 (IC50=10-60nM). Excess of exogenous AA markedly impaired the potency of BRP-187. Direct 5-LO inhibition in cell-free assays was evident only at >35-fold higher concentrations, which was reversible and not improved under reducing conditions. BRP-187 prevented A23187-induced 5-LO/FLAP complex assembly in leukocytes but failed to block 5-LO nuclear translocation, features that were shared with the FLAP inhibitor MK886. Whereas AA release, cyclooxygenases and related LOs were unaffected, BRP-187 also potently inhibited microsomal prostaglandin E2 synthase-1 (IC50=0.2μM), another MAPEG member. In vivo, BRP-187 (10mg/kg) exhibited significant effectiveness in zymosan-induced murine peritonitis, suppressing LT levels in peritoneal exudates as well as vascular permeability and neutrophil infiltration. Together, BRP-187 potently inhibits LT biosynthesis in vitro and in vivo, which seemingly is caused by preventing the 5-LO/FLAP complex assembly and warrants further preclinical evaluation.
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Affiliation(s)
- Ulrike Garscha
- Chair of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich Schiller University Jena, Philosophenweg 14, D-07743 Jena, Germany.
| | - Susanna Voelker
- Chair of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich Schiller University Jena, Philosophenweg 14, D-07743 Jena, Germany.
| | - Simona Pace
- Chair of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich Schiller University Jena, Philosophenweg 14, D-07743 Jena, Germany.
| | - Jana Gerstmeier
- Chair of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich Schiller University Jena, Philosophenweg 14, D-07743 Jena, Germany.
| | - Besa Emini
- Chair of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich Schiller University Jena, Philosophenweg 14, D-07743 Jena, Germany.
| | - Stefanie Liening
- Chair of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich Schiller University Jena, Philosophenweg 14, D-07743 Jena, Germany.
| | - Antonietta Rossi
- Department of Pharmacy, University of Naples Federico II, 80131 Naples, Italy.
| | - Christina Weinigel
- Institute of Transfusion Medicine, University Hospital Jena, 07743 Jena, Germany.
| | - Silke Rummler
- Institute of Transfusion Medicine, University Hospital Jena, 07743 Jena, Germany.
| | - Ulrich S Schubert
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany; Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstrasse 10, D-07743 Jena, Germany.
| | - Gerhard K E Scriba
- Chair of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich Schiller University Jena, Philosophenweg 14, D-07743 Jena, Germany.
| | - Erşan Çelikoğlu
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Gazi University, Etiler, 06330 Yenimahalle, Ankara, Turkey.
| | - Burcu Çalışkan
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Gazi University, Etiler, 06330 Yenimahalle, Ankara, Turkey.
| | - Erden Banoglu
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Gazi University, Etiler, 06330 Yenimahalle, Ankara, Turkey.
| | - Lidia Sautebin
- Department of Pharmacy, University of Naples Federico II, 80131 Naples, Italy.
| | - Oliver Werz
- Chair of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich Schiller University Jena, Philosophenweg 14, D-07743 Jena, Germany; Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany.
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Krait S, Douša M, Scriba GKE. Quality by Design-Guided Development of a Capillary Electrophoresis Method for the Chiral Purity Determination of Ambrisentan. Chromatographia 2016. [DOI: 10.1007/s10337-016-3137-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Zhu Q, El-Mergawy RG, Zhou Y, Chen C, Heinemann SH, Schönherr R, Robaa D, Sippl W, Scriba GKE. Stereospecific capillary electrophoresis assays using pentapeptide substrates for the study of Aspergillus nidulans methionine sulfoxide reductase A and mutant enzymes. Electrophoresis 2016; 37:2083-90. [PMID: 27145186 DOI: 10.1002/elps.201600181] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 04/27/2016] [Accepted: 04/27/2016] [Indexed: 12/18/2022]
Abstract
Stereospecific capillary electrophoresis-based methods for the analysis of methionine sulfoxide [Met(O)]-containing pentapeptides were developed in order to investigate the reduction of Met(O)-containing peptide substrates by recombinant Aspergillus nidulans methionine sulfoxide reductase A (MsrA) as well as enzymes carrying mutations in position Glu99 and Asp134. The separation of the diastereomers of the N-acetylated, C-terminally 2,4-dinitrophenyl (Dnp)-labeled pentapeptides ac-Lys-Phe-Met(O)-Lys-Lys-Dnp, ac-Lys-Asp-Met(O)-Asn-Lys-Dnp and ac-Lys-Asn-Met(O)-Asp-Lys-Dnp was achieved in 50 mM Tris-HCl buffers containing sulfated β-CD in fused-silica capillaries, while the diastereomer separation of ac-Lys-Asp-Met(O)-Asp-Lys-Dnp was achieved by sulfated β-CD-mediated MEKC. The methods were validated with regard to range, linearity, accuracy, limits of detection and quantitation as well as precision. Subsequently, the substrates were incubated with wild-type MsrA and three mutants in the presence of dithiothreitol as reductant. Wild-type MsrA displayed the highest activity towards all substrates compared to the mutants. Substitution of Glu99 by Gln resulted in the mutant with the lowest activity towards all substrates except for ac-Lys-Asn-Met(O)-Asp-Lys-Dnp, while replacement Asn for Asp134 lead to a higher activity towards ac-Lys-Asp-Met(O)-Asn-Lys-Dnp compared with the Glu99 mutant. The mutant with Glu instead of Asp134 was the most active among the mutant enzymes. Molecular modeling indicated that the conserved Glu99 residue is buried in the Met-S-(O) groove, which might contribute to the correct placing of substrates and, consequently, to the catalytic activity of MsrA, while Asp134 did not form hydrogen bonds with the substrates but only within the enzyme.
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Affiliation(s)
- Qingfu Zhu
- Department of Pharmaceutical Chemistry, Friedrich Schiller University Jena, Jena, Germany
| | - Rabab G El-Mergawy
- Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Jena, Germany
| | - Yuzhen Zhou
- Department of Pharmaceutical Chemistry, Friedrich Schiller University Jena, Jena, Germany
| | - Chunyang Chen
- Department of Pharmaceutical Chemistry, Friedrich Schiller University Jena, Jena, Germany
| | - Stefan H Heinemann
- Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Jena, Germany
| | - Roland Schönherr
- Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Jena, Germany
| | - Dina Robaa
- Department of Medicinal Chemistry, University of Halle, Halle, Germany
| | - Wolfgang Sippl
- Department of Medicinal Chemistry, University of Halle, Halle, Germany
| | - Gerhard K E Scriba
- Department of Pharmaceutical Chemistry, Friedrich Schiller University Jena, Jena, Germany
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Abstract
Stereospecific recognition of chiral molecules is an important issue in various aspects of life sciences and chemistry including analytical separation sciences. The basis of analytical enantioseparations is the formation of transient diastereomeric complexes driven by hydrogen bonds or ionic, ion-dipole, dipole-dipole, van der Waals as well as π-π interactions. Recently, halogen bonding was also described to contribute to selector-selectand complexation. Besides structure-separation relationships, spectroscopic techniques, especially NMR spectroscopy, as well as X-ray crystallography have contributed to the understanding of the structure of the diastereomeric complexes. Molecular modeling has provided the tool for the visualization of the structures. The present review highlights recent contributions to the understanding of the binding mechanism between chiral selectors and selectands in analytical enantioseparations dating between 2012 and early 2016 including polysaccharide derivatives, cyclodextrins, cyclofructans, macrocyclic glycopeptides, proteins, brush-type selectors, ion-exchangers, polymers, crown ethers, ligand-exchangers, molecular micelles, ionic liquids, metal-organic frameworks and nucleotide-derived selectors. A systematic compilation of all published literature on the various chiral selectors has not been attempted.
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Affiliation(s)
- Gerhard K E Scriba
- Friedrich Schiller University Jena, Department of Pharmaceutical/Medicinal Chemistry, Philosophenweg 14, 07743 Jena, Germany.
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Abstract
Peptides are an important class of analytes in chemistry, biochemistry, food chemistry, as well as medical and pharmaceutical sciences including biomarker analysis in peptidomics and proteomics. As a high-resolution technique, capillary electrophoresis (CE) is well suited for the analysis of polar compounds such as peptides. In addition, CE is orthogonal to high-performance liquid chromatography (HPLC) as both techniques are based on different physicochemical separation principles. For the successful development of peptide separations by CE, operational parameters including puffer pH, buffer concentration and buffer type, applied voltage, capillary dimensions, as well as background electrolyte additives such as detergents, ion-pairing reagents, cyclodextrins, (poly)amines, and soluble polymers have to be considered and optimized.
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Affiliation(s)
- Gerhard K E Scriba
- Department of Pharmaceutical Chemistry, University of Jena, Philosophenweg 14, Jena, 07743, Germany.
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Abstract
Capillary electrophoresis (CE) is a versatile and flexible technique for analytical enantioseparations. This is due to the large variety of chiral selectors as well as the different operation modes including electrokinetic chromatography, micellar electrokinetic chromatography, and microemulsion electrokinetic chromatography. The chiral selector, which is added to the background electrolyte, represents a pseudostationary phase with its own electrophoretic mobility allowing a variety of different separation protocols. The present chapter briefly addresses the basic fundamentals of CE enantioseparations as well as the most frequently applied chiral selectors and separation modes. The practical example illustrates the separation of the enantiomers of a positively charged analyte using native and charged cyclodextrin derivatives as chiral selectors.
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Affiliation(s)
- Gerhard K E Scriba
- Department of Pharmaceutical Chemistry, University of Jena, Philosophenweg 14, Jena, 07743, Germany.
| | - Henrik Harnisch
- Department of Pharmaceutical Chemistry, University of Jena, Philosophenweg 14, Jena, 07743, Germany
| | - Qingfu Zhu
- Department of Chemistry, Wichita State University, 1845 Fairmount St, Wichita, KS, 67260, USA
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Knoth H, Scriba GKE, Buettner B. Electrochemical behavior of the antifungal agents itraconazole, posaconazole and ketoconazole at a glassy carbon electrode. Pharmazie 2015; 70:374-378. [PMID: 26189297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The electrochemical behavior of the azole antifungal agents itraconazole, posaconazole and ketoconazole has been investigated at a glassy carbon working electrode using cyclic voltammetry. All measurements were carried out in a supporting electrolyte solution consisting of a 1:1 (v/v) mixture of 0.1 mol L(-1) sodium phosphate buffers and acetonitrile at various substance concentrations and pH values. An amperometric cell with a three electrode system consisting of a working electrode, a palladium reference electrode and a platinum disk as the auxiliary electrode was used in all experiments. All azoles showed a similar electrochemical behavior involving two reactions. An irreversible oxidation occurred at potentials of about 0.5V. A reduction peak was detected at potentials between -0.28V and -0.14V with an associated oxidation peak, which was observed in consecutive repeated measurements at potentials between -0.03 and 0.28 V. The reduction and corresponding oxidation can be regarded as a quasi-reversible process. The proposed reaction mechanisms are an irreversible oxidation of the piperazine moiety at higher potentials as well as a reduction at lower potentials of the carbonyl group of the triazolone moiety in the case of itraconazole and posaconazole or a reduction of the methoxy group of ketoconazole.
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Lingeman H, Scriba GKE. In Memoriam: Professor Karl-Siegfried Boos (1948–2014). Chromatographia 2014. [DOI: 10.1007/s10337-014-2793-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Zhu Q, Heinemann SH, Schönherr R, Scriba GKE. Capillary electrophoresis separation of peptide diastereomers that contain methionine sulfoxide by dual cyclodextrin-crown ether systems. J Sep Sci 2014; 37:3548-54. [PMID: 25216019 DOI: 10.1002/jssc.201400825] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 09/03/2014] [Accepted: 09/04/2014] [Indexed: 12/12/2022]
Abstract
A dual-selector system employing achiral crown ethers in combination with cyclodextrins has been developed for the separation of peptide diastereomers that contain methionine sulfoxide. The combinations of the crown ethers 15-crown-5, 18-crown-6, Kryptofix® 21 and Kryptofix® 22 and β-cyclodextrin, carboxymethyl-β-cyclodextrin, and sulfated β-cyclodextrin were screened at pH 2.5 and pH 8.0 using a 40/50.2 cm, 50 μm id fused-silica capillary and a separation voltage of 25 kV. No diastereomer separation was observed in the sole presence of crown ethers, while only sulfated β-cyclodextrin was able to resolve some peptide diastereomers at pH 8.0. Depending on the amino acid sequence of the peptide and the applied cyclodextrin, the addition of crown ethers, especially the Krpytofix® diaza-crown ethers, resulted in significantly enhanced chiral recognition. Keeping one selector of the dual system constant, increasing concentrations of the second selector resulted in increased peak resolution and analyte migration time for peptide-crown ether-cyclodextrin combinations. The simultaneous diastereomer separation of three structurally related peptides was achieved using the dual selector system.
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Affiliation(s)
- Qingfu Zhu
- Department of Pharmaceutical/Medicinal Chemistry, Friedrich Schiller University Jena, Jena, Germany
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Deeb SE, Wätzig H, El-Hady DA, Albishri HM, de Griend CSV, Scriba GKE. Recent advances in capillary electrophoretic migration techniques for pharmaceutical analysis. Electrophoresis 2014; 35:170-89. [PMID: 24395663 DOI: 10.1002/elps.201300411] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 10/04/2013] [Accepted: 10/04/2013] [Indexed: 12/31/2022]
Abstract
Since the introduction about 30 years ago, CE techniques have gained a significant impact in pharmaceutical analysis. The present review covers recent advances and applications of CE for the analysis of pharmaceuticals. Both small molecules and biomolecules such as proteins are considered. The applications range from the determination of drug-related substances to the analysis of counterions and the determination of physicochemical parameters. Furthermore, general considerations of CE methods in pharmaceutical analysis are described.
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Affiliation(s)
- Sami El Deeb
- Drug Analysis and Research Center, Department of Pharmaceutical Chemistry, Al-Azhar University - Gaza, Gaza, Palestine; Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Germany
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32
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Aranyi A, Péter A, Ilisz I, Fülöp F, Scriba GKE. Cyclodextrin-mediated enantioseparation of phenylalanine amide derivatives and amino alcohols by capillary electrophoresis-Role of complexation constants and complex mobilities. Electrophoresis 2014; 35:2848-54. [DOI: 10.1002/elps.201400142] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Revised: 05/22/2014] [Accepted: 05/24/2014] [Indexed: 02/03/2023]
Affiliation(s)
- Anita Aranyi
- Department of Inorganic and Analytical Chemistry; University of Szeged; Szeged Hungary
- Department of Pharmaceutical Chemistry; Friedrich Schiller University of Jena; Jena Germany
| | - Antal Péter
- Department of Inorganic and Analytical Chemistry; University of Szeged; Szeged Hungary
| | - István Ilisz
- Department of Inorganic and Analytical Chemistry; University of Szeged; Szeged Hungary
| | - Ferenc Fülöp
- Institute of Pharmaceutical Chemistry; University of Szeged; Szeged Hungary
| | - Gerhard K. E. Scriba
- Department of Pharmaceutical Chemistry; Friedrich Schiller University of Jena; Jena Germany
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33
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Zhu Q, Huo X, Heinemann SH, Schönherr R, El-Mergawy R, Scriba GKE. Experimental design-guided development of a stereospecific capillary electrophoresis assay for methionine sulfoxide reductase enzymes using a diastereomeric pentapeptide substrate. J Chromatogr A 2014; 1359:224-9. [PMID: 25064531 DOI: 10.1016/j.chroma.2014.07.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 06/16/2014] [Accepted: 07/06/2014] [Indexed: 02/05/2023]
Abstract
A capillary electrophoresis method has been developed and validated to evaluate the stereospecific activity of recombinant human methionine sulfoxide reductase enzymes employing the C-terminally dinitrophenyl-labeled N-acetylated pentapeptide ac-KIFM(O)K-Dnp as substrate (M(O)=methionine sulfoxide). The separation of the ac-KIFM(O)K-Dnp diastereomers and the reduced peptide ac-KIFMK-Dnp was optimized using experimental design with regard to the buffer pH, buffer concentration, sulfated β-cyclodextrin and 15-crown-5 concentration as well as capillary temperature and separation voltage. A fractional factorial response IV design was employed for the identification of the significant factors and a five-level circumscribed central composite design for the final method optimization. Resolution of the peptide diastereomers as well as analyte migration time served as responses in both designs. The resulting optimized conditions included 50mM Tris buffer, pH 7.85, containing 5mM 15-crown-5 and 14.3mg/mL sulfated β-cyclodextrin, at an applied voltage of 25kV and a capillary temperature of 21.5°C. The assay was subsequently applied to the determination of the stereospecificity of recombinant human methionine sulfoxide reductases A and B2. The Michaelis-Menten kinetic data were determined. The pentapeptide proved to be a good substrate for both enzymes. Furthermore, the first separation of methionine sulfoxide peptide diastereomers is reported.
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Affiliation(s)
- Qingfu Zhu
- Department of Pharmaceutical Chemistry, Friedrich Schiller University Jena, Philosophenweg 14, 07743 Jena, Germany
| | - Xingyu Huo
- School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, PR China
| | - Stefan H Heinemann
- Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Hans-Knöll-Straße 2, 07745 Jena, Germany
| | - Roland Schönherr
- Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Hans-Knöll-Straße 2, 07745 Jena, Germany
| | - Rabab El-Mergawy
- Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Hans-Knöll-Straße 2, 07745 Jena, Germany
| | - Gerhard K E Scriba
- Department of Pharmaceutical Chemistry, Friedrich Schiller University Jena, Philosophenweg 14, 07743 Jena, Germany.
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34
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Schmidt M, Reinscheid F, Sun H, Abromeit H, Scriba GKE, Sönnichsen FD, John M, Reinscheid UM. Hidden Flexibility of Strychnine. European J Org Chem 2014. [DOI: 10.1002/ejoc.201301760] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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35
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Abromeit H, Wu F, Scriba GKE. SPE of 5-lipoxygenase metabolites and the effect of head-column field-amplified sample stacking in MEKC. J Sep Sci 2013; 36:3592-8. [DOI: 10.1002/jssc.201300678] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 08/27/2013] [Accepted: 08/29/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Hans Abromeit
- Department of Pharmaceutical/Medicinal Chemistry; Friedrich Schiller University Jena; Jena Germany
| | - Fengyi Wu
- Department of Pharmaceutical/Medicinal Chemistry; Friedrich Schiller University Jena; Jena Germany
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery; Wuhan University; Ministry of Education and School of Pharmaceutical Sciences; Wuhan PR China
| | - Gerhard K. E. Scriba
- Department of Pharmaceutical/Medicinal Chemistry; Friedrich Schiller University Jena; Jena Germany
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36
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Zhu Q, El-Mergawy RG, Heinemann SH, Schönherr R, Jáč P, Scriba GKE. Stereospecific micellar electrokinetic chromatography assay of methionine sulfoxide reductase activity employing a multiple layer coated capillary. Electrophoresis 2013; 34:2712-7. [DOI: 10.1002/elps.201300147] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 04/18/2013] [Accepted: 04/20/2013] [Indexed: 12/13/2022]
Affiliation(s)
- Qingfu Zhu
- Department of Pharmaceutical Chemistry; Friedrich Schiller University Jena; Jena; Germany
| | - Rabab G. El-Mergawy
- Department of Biophysics; Friedrich Schiller University Jena and Jena University Hospital; Jena; Germany
| | - Stefan H. Heinemann
- Department of Biophysics; Friedrich Schiller University Jena and Jena University Hospital; Jena; Germany
| | - Roland Schönherr
- Department of Biophysics; Friedrich Schiller University Jena and Jena University Hospital; Jena; Germany
| | - Pavel Jáč
- Department of Pharmaceutical Chemistry; Friedrich Schiller University Jena; Jena; Germany
| | - Gerhard K. E. Scriba
- Department of Pharmaceutical Chemistry; Friedrich Schiller University Jena; Jena; Germany
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37
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Brückner C, Bunz SC, Imhof D, Neusüß C, Scriba GKE. Isomerization and epimerization of the aspartyl tetrapeptide Ala-Phe-Asp-GlyOH at pH 10-A CE study. Electrophoresis 2013; 34:2666-73. [DOI: 10.1002/elps.201200685] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 01/11/2013] [Accepted: 01/16/2013] [Indexed: 12/12/2022]
Affiliation(s)
- Christin Brückner
- Department of Pharmaceutical Chemistry; School of Pharmacy; Friedrich Schiller University Jena; Jena; Germany
| | | | - Diana Imhof
- Department of Pharmaceutical Chemistry I; School of Pharmacy; University of Bonn; Bonn; Germany
| | | | - Gerhard K. E. Scriba
- Department of Pharmaceutical Chemistry; School of Pharmacy; Friedrich Schiller University Jena; Jena; Germany
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38
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Abstract
Chiral recognition phenomena play an important role in nature as well as analytical separation sciences. In separation sciences such as chromatography and capillary electrophoresis, enantiospecific interactions between the enantiomers of an analyte and the chiral selector are required in order to observe enantioseparations. Due to the large structural variety of chiral selectors applied, different mechanisms and structural features contribute to the chiral recognition process. This chapter briefly illustrates the current models of the enantiospecific recognition on the structural basics of various chiral selectors.
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Affiliation(s)
- Gerhard K E Scriba
- Department of Pharmaceutical/Medicinal Chemistry, Friedrich Schiller University Jena, Jena, Germany.
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39
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Abstract
Capillary electrophoresis (CE) has matured to one of the major liquid phase enantiodifferentiation techniques since the first report in 1985. This can be primarily attributed to the flexibility as well as the various modes available including electrokinetic chromatography (EKC), micellar electrokinetic chromatography (MEKC), and microemulsion electrokinetic chromatography (MEEKC). In contrast to chromatographic techniques, the chiral selector is mobile in the background electrolyte. Furthermore, a large variety of chiral selectors are available that can be easily combined in the same separation system. In addition, the migration order of the enantiomers can be adjusted by a number of approaches. In CE enantiodifferentiations the separation principle is comparable to chromatography while the principle of the movement of the analytes in the capillary is based on electrophoretic phenomena. The present chapter will focus on mechanistic aspects of CE enantioseparations including enantiomer migration order and the current understanding of selector-selectand structures. Selected examples of the basic enantioseparation modes EKC, MEKC, and MEEKC will be discussed.
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Affiliation(s)
- Gerhard K E Scriba
- Department of Pharmaceutical/Medicinal Chemistry, Friedrich Schiller University Jena, Philosophenweg 14, 07743, Jena, Germany,
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Abstract
In the past years, capillary electrophoresis has become a frequently used technique for enzyme assays due to the high separation efficiency and versatility as well as small sample size and low consumption of chemicals. The capillary electrophoresis assays can be divided into two general categories: pre-capillary (or offline) assays and in-capillary (or online) assays. In pre-capillary assays, the incubation is performed offline and substrate(s) and product(s) are subsequently analyzed by capillary electrophoresis. In in-capillary assays enzyme reaction and separation of the analytes are performed inside the same capillary. In such assays the enzyme is either immobilized or in solution. The latter techniques is also referred to as electrophoretically mediated microanalysis (EMMA) indicating that the individual steps of the incubation as well as analysis are performed via electrophoretic phenomena. This chapter describes both techniques using the deacetylation of acetyl-lysine residues in model peptides by sirtuin enzymes as well as the hydrolysis of acetylthiocholine by acetylcholinesterase as examples.
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Affiliation(s)
- Gerhard K E Scriba
- Department of Pharmaceutical Chemistry, School of Pharmacy, Friedrich Schiller University, Jena, Germany.
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Abstract
Due to their commercial availability, cyclodextrins are the most frequently used chiral selectors in capillary electrophoresis as documented by the numerous publications in the field. A variety of migration modes can be realized depending on the characteristics of the cyclodextrins and the analytes. The basic considerations regarding the development of a chiral CE method employing cyclodextrins as chiral selectors are briefly discussed. The presented examples illustrate the separation modes of an acidic and a basic analyte with native and charged cyclodextrin derivatives as a function of the pH of the background electrolyte and the cyclodextrin concentration.
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Affiliation(s)
- Gerhard K E Scriba
- Department of Pharmaceutical/Medicinal Chemistry, Friedrich Schiller University Jena, Jena, Germany.
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42
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Jáč P, Scriba GKE. Recent advances in electrodriven enantioseparations. J Sep Sci 2012; 36:52-74. [DOI: 10.1002/jssc.201200836] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2012] [Revised: 09/22/2012] [Accepted: 09/22/2012] [Indexed: 01/05/2023]
Affiliation(s)
- Pavel Jáč
- Department of Pharmaceutical Chemistry; School of Pharmacy; Friedrich Schiller University; Jena; Germany
| | - Gerhard K. E. Scriba
- Department of Pharmaceutical Chemistry; School of Pharmacy; Friedrich Schiller University; Jena; Germany
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43
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Abromeit H, Kannan S, Sippl W, Scriba GKE. A new nonpeptide substrate of human sirtuin in a capillary electrophoresis-based assay. Investigation of the binding mode by docking experiments. Electrophoresis 2012; 33:1652-9. [PMID: 22736369 DOI: 10.1002/elps.201100641] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Sirtuins are nicotinamide dinucleotide-dependent class III histone deacetylases catalyzing various physiological processes involved in cell proliferation, differentiation, apoptosis, and ageing. This makes them attractive targets in drug research. In order to simplify sirtuin substrates for assay development, two N(ɛ)-acetyllysine derivatives, N(ɛ)-acetyl-N(α)-(4-methyl-7-methoxycoumarin)lysine amide, and N(ɛ)-acetyl-N(α)-(4-methyl-7-methoxycoumarin)lysine methyl ester were synthesized and evaluated as substrates for human SIRT1 in a capillary electrophoresis-based enzyme assay. Substrate, deacetylated product, and the coproduct nicotinamide were separated in a 200 mM phosphate/Tris buffer at pH 2.85. Field-amplified sample injection was employed to achieve sufficient assay sensitivity. While the ester derivative was not recognized by the enzyme, the amide substrate was effectively converted to the deacetylated product. The assay was subsequently validated with respect to range, linearity, limit of detection, and limit of quantification. Michaelis-Menten kinetic parameters, K(m) = 83 μM and V(max) = 6.8 μM/min were determined. The applicability of the assay for inhibitor screening was demonstrated using the known inhibitors sirtinol and the suramin derivate NF258. Resveratrol did not increase the deacetylation rate at concentrations of up to 200 μM. Docking experiments revealed the necessity of an amide function at the C-terminus of nonpeptide substrates while more structural freedom is tolerated at the N-terminus of N(ɛ) -acetyllysine.
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Affiliation(s)
- Hans Abromeit
- Department of Pharmaceutical Chemistry, Friedrich-Schiller-Universität, Jena, Germany
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Abstract
A microchip-based assay to monitor the conversion of peptide substrates by human recombinant sirtuin 1 (hSIRT1) is presented. For this purpose a fused silica microchip consisting of a microfluidic separation structure with an integrated serpentine micromixer has been used. As substrate for the assay, we used a 9-fluorenylmethoxycarbonyl (Fmoc)-labeled tetrapeptide derived from the amino acid sequence of p53, a known substrate of hSIRT1. The Fmoc group at the N-terminus resulting from solid-phase peptide synthesis enabled deep UV laser-induced fluorescence detection with excitation at 266 nm. The enzymatic reaction of 0.1 U/μL hSIRT1 was carried out within the serpentine micromixer using a 400 μM solution of the peptide in buffer. In order to reduce protein adsorption, the reaction channel was dynamically coated with hydroxypropylmethyl cellulose. The substrate and the deacetylated product were separated by microchip electrophoresis on the same chip. The approach was successfully utilized to screen various SIRT inhibitors.
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Affiliation(s)
- Stefan Ohla
- Institute of University of Leipzig, Analytical Chemistry, Leipzig, Germany
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46
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Schmidt M, Sun H, Rogne P, Scriba GKE, Griesinger C, Kuhn LT, Reinscheid UM. Determining the Absolute Configuration of (+)-Mefloquine HCl, the Side-Effect-Reducing Enantiomer of the Antimalaria Drug Lariam. J Am Chem Soc 2012; 134:3080-3. [DOI: 10.1021/ja209050k] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Manuel Schmidt
- Department of NMR-Based Structural
Biology, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Han Sun
- Department of NMR-Based Structural
Biology, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Per Rogne
- European Neuroscience Institute Göttingen (ENI-G), Grisebachstraße
5, 37077 Göttingen, Germany
- DFG Research Center Molecular Physiology of the Brain (CMPB) and Cluster
of Excellence 171 “Microscopy at the Nanometer
Range”, Göttingen, Germany
| | - Gerhard K. E. Scriba
- Department of Pharmaceutical
Chemistry, University of Jena, Philosophenweg
14, 07743 Jena, Germany
| | - Christian Griesinger
- Department of NMR-Based Structural
Biology, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Lars T. Kuhn
- European Neuroscience Institute Göttingen (ENI-G), Grisebachstraße
5, 37077 Göttingen, Germany
- DFG Research Center Molecular Physiology of the Brain (CMPB) and Cluster
of Excellence 171 “Microscopy at the Nanometer
Range”, Göttingen, Germany
| | - Uwe M. Reinscheid
- Department of NMR-Based Structural
Biology, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
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Vega ED, Lomsadze K, Chankvetadze L, Salgado A, Scriba GKE, Calvo E, López JA, Crego AL, Marina ML, Chankvetadze B. Separation of enantiomers of ephedrine by capillary electrophoresis using cyclodextrins as chiral selectors: Comparative CE, NMR and high resolution MS studies. Electrophoresis 2011; 32:2640-7. [DOI: 10.1002/elps.201100015] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 03/04/2011] [Accepted: 03/05/2011] [Indexed: 11/11/2022]
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Wongwan S, Scriba GKE. Development and validation of a capillary electrophoresis assay for the determination of the stereoisomeric purity of chloroquine enantiomers. Electrophoresis 2011; 32:2669-72. [DOI: 10.1002/elps.201000610] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Revised: 01/11/2011] [Accepted: 01/26/2011] [Indexed: 11/06/2022]
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Taichrib A, Scriba GKE, Neusüß C. Identification and characterization of impurities of tetracosactide by capillary electrophoresis and liquid chromatography coupled to time-of-flight mass spectrometry. Anal Bioanal Chem 2011; 401:1365-75. [DOI: 10.1007/s00216-011-5183-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 06/09/2011] [Accepted: 06/13/2011] [Indexed: 12/19/2022]
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Ludewig R, Nietzsche S, Scriba GKE. A weak cation-exchange monolith as stationary phase for the separation of peptide diastereomers by CEC. J Sep Sci 2010; 34:64-9. [DOI: 10.1002/jssc.201000616] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Revised: 09/30/2010] [Accepted: 09/30/2010] [Indexed: 11/11/2022]
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