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Felletti S, De Luca C, Ismail OH, Pasti L, Costa V, Gasparrini F, Cavazzini A, Catani M. On the effect of chiral selector loading and mobile phase composition on adsorption properties of latest generation fully- and superficially-porous Whelk-O1 particles for high-efficient ultrafast enantioseparations. J Chromatogr A 2018; 1579:41-48. [DOI: 10.1016/j.chroma.2018.10.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 10/09/2018] [Accepted: 10/14/2018] [Indexed: 11/28/2022]
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2
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Asnin LD, Stepanova MV. Van't Hoff analysis in chiral chromatography. J Sep Sci 2018; 41:1319-1337. [DOI: 10.1002/jssc.201701264] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 12/27/2017] [Accepted: 12/28/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Leonid D. Asnin
- Department of Chemistry and Biotechnology; Perm National Research Polytechnic University; Perm Russia
| | - Maria V. Stepanova
- Department of Chemistry and Biotechnology; Perm National Research Polytechnic University; Perm Russia
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Imre S, Ormenişan A, Tero-Vescan A, Muntean DL, Vari CE. HPLC Enantioseparation of β-Blockers on Ovomucoid Stationary Phase†. J Chromatogr Sci 2016; 54:1578-1583. [PMID: 27402671 DOI: 10.1093/chromsci/bmw107] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 05/05/2016] [Indexed: 11/12/2022]
Abstract
The purpose of this study was to separate single and multiple pairs of six β-blockers enantiomers by high performance liquid chromatography on ovomucoid (OM) column in optimal conditions. The separation was performed isocratically or in gradient elution at 25°C, flow rate of 1 mL/min and 220 nm. The mobile phase consisted of phosphate buffer/acetonitrile or methanol. The effect of the organic modifier, the influence of pH and the percentage of the aqueous phase on resolution were investigated. The elution order of propranolol (PRP) enantiomers was established as well as the detection and quantification limits. The results show that OM was suitable for enantiomeric separation of the nonselective β-blockers carvedilol, PRP, pindolol and oxprenolol, and not for the two β-1 selective blockers, atenolol and metoprolol. A hypothesis regarding a possible correlation between structure-pharmacological activity-chromatographic behavior is proposed.
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Affiliation(s)
- Silvia Imre
- Faculty of Pharmacy, University of Medicine and Pharmacy from Tîrgu Mureş, Gheorghe Marinescu Street 38, 540139 Tîrgu Mureş, Romania
| | - Anca Ormenişan
- Faculty of Pharmacy, University of Medicine and Pharmacy from Tîrgu Mureş, Gheorghe Marinescu Street 38, 540139 Tîrgu Mureş, Romania.,Sensiblu 1 Pharmacy, Alba Iulia, Romania
| | - Amelia Tero-Vescan
- Faculty of Pharmacy, University of Medicine and Pharmacy from Tîrgu Mureş, Gheorghe Marinescu Street 38, 540139 Tîrgu Mureş, Romania
| | - Daniela-Lucia Muntean
- Faculty of Pharmacy, University of Medicine and Pharmacy from Tîrgu Mureş, Gheorghe Marinescu Street 38, 540139 Tîrgu Mureş, Romania
| | - Camil-Eugen Vari
- Faculty of Pharmacy, University of Medicine and Pharmacy from Tîrgu Mureş, Gheorghe Marinescu Street 38, 540139 Tîrgu Mureş, Romania
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Comparative studies of peak intensities and chromatographic separation of proteolytic digests, PTMs, and intact proteins obtained by nanoLC-ESI MS analysis at room and elevated temperatures. Anal Bioanal Chem 2016; 408:3953-68. [DOI: 10.1007/s00216-016-9386-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 01/26/2016] [Accepted: 02/01/2016] [Indexed: 12/26/2022]
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6
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Adsorption models in chiral chromatography. J Chromatogr A 2012; 1269:3-25. [DOI: 10.1016/j.chroma.2012.08.096] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 08/26/2012] [Accepted: 08/28/2012] [Indexed: 12/20/2022]
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7
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The adsorption of Naproxen enantiomers on the chiral stationary phase Whelk-O1 under reversed-phase conditions: The effect of buffer composition. J Chromatogr A 2010; 1217:7055-64. [DOI: 10.1016/j.chroma.2010.08.073] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Revised: 07/29/2010] [Accepted: 08/26/2010] [Indexed: 11/24/2022]
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8
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Stevenson PG, Gritti F, Guiochon G, Mayfield KJ, Dennis GR, Shalliker RA. π-Selective stationary phases: (II) Adsorption behaviour of substituted aromatic compounds on n-alkyl-phenyl stationary phases. J Chromatogr A 2010; 1217:5365-76. [DOI: 10.1016/j.chroma.2010.04.064] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Revised: 04/15/2010] [Accepted: 04/22/2010] [Indexed: 10/19/2022]
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9
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Characterization of adsorption processes in analytical liquid–solid chromatography. J Chromatogr A 2010; 1217:792-812. [DOI: 10.1016/j.chroma.2009.12.044] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Revised: 12/15/2009] [Accepted: 12/17/2009] [Indexed: 11/22/2022]
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10
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Lämmerhofer M. Chiral recognition by enantioselective liquid chromatography: mechanisms and modern chiral stationary phases. J Chromatogr A 2009; 1217:814-56. [PMID: 19906381 DOI: 10.1016/j.chroma.2009.10.022] [Citation(s) in RCA: 514] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Revised: 09/30/2009] [Accepted: 10/07/2009] [Indexed: 11/19/2022]
Abstract
An overview of the state-of-the-art in LC enantiomer separation is presented. This tutorial review is mainly focused on mechanisms of chiral recognition and enantiomer distinction of popular chiral selectors and corresponding chiral stationary phases including discussions of thermodynamics, additivity principle of binding increments, site-selective thermodynamics, extrathermodynamic approaches, methods employed for the investigation of dominating intermolecular interactions and complex structures such as spectroscopic methods (IR, NMR), X-ray diffraction and computational methods. Modern chiral stationary phases are discussed with particular focus on those that are commercially available and broadly used. It is attempted to provide the reader with vivid images of molecular recognition mechanisms of selected chiral selector-selectand pairs on basis of solid-state X-ray crystal structures and simulated computer models, respectively. Such snapshot images illustrated in this communication unfortunately cannot account for the molecular dynamics of the real world, but are supposed to be helpful for the understanding. The exploding number of papers about applications of various chiral stationary phases in numerous fields of enantiomer separations is not covered systematically.
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Affiliation(s)
- Michael Lämmerhofer
- Christian Doppler Laboratory for Molecular Recognition Materials, Department of Analytical Chemistry and Food Chemistry, University of Vienna, Waehringer Strasse 38, A-1090 Vienna, Austria.
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11
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Samuelsson J, Arnell R, Fornstedt T. Potential of adsorption isotherm measurements for closer elucidating of binding in chiral liquid chromatographic phase systems. J Sep Sci 2009; 32:1491-506. [DOI: 10.1002/jssc.200900165] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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12
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Szabelski P, Kaczmarski K. Phenomenological modeling of separation of enantiomers by nonlinear chromatography. ACTA CHROMATOGR 2008. [DOI: 10.1556/achrom.20.2008.4.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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13
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Wang Z, Ouyang J, Baeyens WR. Recent developments of enantioseparation techniques for adrenergic drugs using liquid chromatography and capillary electrophoresis: A review. J Chromatogr B Analyt Technol Biomed Life Sci 2008; 862:1-14. [DOI: 10.1016/j.jchromb.2007.11.034] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Revised: 10/20/2007] [Accepted: 11/23/2007] [Indexed: 10/22/2022]
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15
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Szabelski P, Kaczmarski K. Theoretical investigations of the chromatographic separation of interacting enantiomers. J Chromatogr A 2006; 1113:74-83. [PMID: 16473359 DOI: 10.1016/j.chroma.2006.01.119] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2005] [Revised: 01/25/2006] [Accepted: 01/27/2006] [Indexed: 10/25/2022]
Abstract
Separation of a pair of enantiomers by liquid chromatography is modeled using the equilibrium dispersive (ED) model of chromatography. It is assumed that the chiral stationary phase used for the separation consists of two types of adsorption sites, including chiral selectors linked to the surface and nonselective centers belonging to the achiral matrix. Additionally, intermolecular interactions between adsorbed enantiomers are taken into account. The corresponding equilibrium adsorption isotherms of the enantiomers are derived by means of the mean field approximation (MFA) and used as input data for the ED model. Special attention is paid to the influence of the lateral interactions on the effectiveness of the enantiomer separation. In particular, we examine the effect of the interactions on the shape and relative position of the chromatographic peaks associated with the enantiomers. Furthermore, the influence of the spacer length, which modifies screening of the lateral interactions, on the adsorption process is studied. The obtained results suggest that the lateral interactions combined with the screening effect may cause serious changes in the separation, depending on the nature (attraction or repulsion) and strength of the interactions as well as on the spacer length.
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Affiliation(s)
- Paweł Szabelski
- Department of Theoretical Chemistry, Faculty of Chemistry, Maria Curie-Skłodowska University, Pl. M.C. Skłodowskiej 3, 20-031 Lublin, Poland.
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16
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Gritti F, Guiochon G. Critical contribution of nonlinear chromatography to the understanding of retention mechanism in reversed-phase liquid chromatography. J Chromatogr A 2005; 1099:1-42. [PMID: 16271269 DOI: 10.1016/j.chroma.2005.09.082] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2005] [Revised: 09/23/2005] [Accepted: 09/27/2005] [Indexed: 11/25/2022]
Abstract
The retention of most compounds in RPLC proceeds through a combination of several independent mechanisms. We review a series of recent studies made on the behavior of several commercial C18-bonded stationary phases and of the complex, mixed retention mechanisms that were observed in RPLC. These studies are essentially based on the acquisition of adsorption isotherm data, on the modeling, and on the interpretation of these data. Because linear chromatography deals only with the initial slope of the global, overall, or apparent isotherm, it is unable fully to describe the complete adsorption mechanism. It cannot even afford clues as to the existence of several overlaid retention mechanisms. More specifically, it cannot account for the consequences of the surface heterogeneity of the packing material. The acquisition of equilibrium data in a wide concentration range is required for this purpose. Frontal analysis (FA) of selected probes gives data that can be modeled into equilibrium isotherms of these probes and that can also be used to calculate their adsorption or affinity energy distribution (AED). The combination of these data, the detailed study of the best constants of the isotherm model, the determination of the influence of experimental parameters (e.g., buffer pH and pI, temperature) on the isotherm constants provide important clues regarding the heterogeneity of the adsorbent surface and the main properties of the adsorption mechanisms. The comparison of similar data obtained for the adsorption of neutral and ionizable compounds, treated with the same approach, and the investigation of the influence on the thermodynamics of phase equilibrium of the experimental conditions (temperature, average pressure, mobile phase composition, nature of the organic modifier, and, for ionizable compounds, of the ionic strength, the nature, the concentration of the buffer, and its pH) brings further information. This review provides original conclusions regarding retention mechanisms in RPLC.
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Affiliation(s)
- Fabrice Gritti
- Department of Chemistry, University of Tennessee, Knoxville, TN 37996-1600, USA
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17
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Götmar G, Asnin L, Guiochon G. Adsorption of the enantiomers of 2,2,2-trifluoro-1-(9-anthryl)-ethanol on silica-bonded chiral quinidine-carbamate. J Chromatogr A 2004; 1059:43-52. [PMID: 15628123 DOI: 10.1016/j.chroma.2004.10.025] [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] [Indexed: 10/26/2022]
Abstract
The adsorption isotherms of the enantiomers of 2,2,2-trifluoro-1-(9-anthryl)-ethanol from a toluene-acetonitrile solution onto a Chiris Chiral AX:QD1 column were measured using the pulse method. The isotherm data were modeled with a bi-Langmuir isotherm model, indicating the presence of two different types of adsorption sites on this stationary phase, nonselective and enantioselective sites. The latter are homogeneous but interact with both enantiomers, albeit with different energies. The thermodynamic characteristics of these two types of sites were characterized by their adsorption constants and saturation capacities and by the influence of the temperature on these different parameters.
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Affiliation(s)
- Gustaf Götmar
- Department of Chemistry, The University of Tennessee, Knoxville, TN 37996-1600, USA.
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18
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Götmar G, Ozen C, Serpersu E, Guiochon G. Isothermal microcalorimetric study of the pH dependence of the interactions between a cellulase and a β-blocker. J Chromatogr A 2004. [DOI: 10.1016/j.chroma.2004.06.089] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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19
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Szabelski P, Talbot J. Kinetics and equilibrium of multicomponent adsorption on chiraly templated surfaces. J Comput Chem 2004; 25:1779-86. [PMID: 15362135 DOI: 10.1002/jcc.20107] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In this contribution we propose a simple model of adsorption of a binary (racemic) mixture on a chiraly templated surface. As an example, the adsorption of a liquid mixture of enantiomers on a chiral stationary phase (CSP) is considered. In particular, we study the effect of the lateral interactions in the adsorbed phase on the kinetic and equilibrium isotherms of the enantiomers. Additionally, we investigate the influence of the composition of the surface on the performance of the CSP in the presence of the lateral interactions. To that end, the adsorption of the mixture is modeled by using Monte Carlo simulations as well as by applying an analytical approach involving rate equations coupled with the Mean Field Approximation (MFA). The predictions of the theory are found to be in good agreement with the results of the simulations.
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Affiliation(s)
- Paweł Szabelski
- Department of Theoretical Chemistry, Faculty of Chemistry, Maria Curie-Skłodowska University, Pl. M.C. Skłodowskiej 3, 20-031 Lublin, Poland.
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20
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Abstract
Molecular Chirality is of central interest in biological studies because enantiomeric compounds, while indistinguishable by most inanimate systems, show profoundly different properties in biochemical environments. Enantioselective separation methods, based on the differential recognition of two optical isomers by a chiral selector, have been amply documented. Also, great effort has been directed towards a theoretical understanding of the fundamental mechanisms underlying the chiral recognition process. Here we report a comprehensive data examination of enantio separation measurements for over 72000 chiral selector-select and pairs from the chiral selection compendium CHIRBASE. The distribution of alpha = k'(D)/k'(L) values was found to follow a power law, equivalent to an exponential decay for chiral differential free energies. This observation is experimentally relevant in terms of the number of different individual or combinatorial selectors that need to be screened in order to observe alpha values higher than a preset minimum. A string model for enantiorecognition (SMED) formalism is proposed to account for this observation on the basis of an extended Ogston three-point interaction model. Partially overlapping molecular interaction domains are analyzed in terms of a string complementarity model for ligand-receptor complementarity. The results suggest that chiral selection statistics may be interpreted in terms of more general concepts related to biomolecular recognition.
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Affiliation(s)
- Ran Kafri
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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21
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Liu X, Szabelski P, Kaczmarski K, Zhou D, Guiochon G. Influence of pressure on the chromatographic behavior of insulin variants under nonlinear conditions. J Chromatogr A 2003; 988:205-18. [PMID: 12641157 DOI: 10.1016/s0021-9673(03)00002-5] [Citation(s) in RCA: 41] [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
The effect of pressure on the chromatographic behavior of two insulin variants in RPLC was investigated on a YMC-ODS C18 column, under nonlinear conditions. The adsorption isotherm data of porcine insulin and Lispro were measured at average column pressures ranging from 52 to 242 bar. These data fit well to the Toth and the bi-Langmuir isotherm models. The saturation capacity increases rapidly with increasing pressure while the affinity (or equilibrium) constant and the parameter characterizing the surface heterogeneity decrease. It is noteworthy that the distribution coefficient of the insulin variants increases with increasing pressure whereas their equilibrium constant b decreases for porcine insulin and increases for Lispro. The association constant b(ds), which characterizes the adsorption and desorption equilibrium of insulin in the system, increases with increasing pressure. The excellent agreement between the experimental overloaded profiles recorded under different pressures and those calculated using the POR model suggests that the chromatographic behavior of insulin is controlled more by equilibrium thermodynamics than by the mass transfer kinetics. The latter seems to be nearly independent of the average column pressure. Thus, increasing the average column pressure is an efficient, albeit costly, way to increase the loading capacity of the column, hence the production rate in preparative chromatography.
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Affiliation(s)
- Xiaoda Liu
- Department of Chemistry, The University of Tennessee, Buchler Hall, Knoxville, TN 37996-1600, USA
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22
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Loukili B, Dufresne C, Jourdan E, Grosset C, Ravel A, Villet A, Peyrin E. Study of tryptophan enantiomer binding to a teicoplanin-based stationary phase using the perturbation technique. Investigation of the role of sodium perchlorate in solute retention and enantioselectivity. J Chromatogr A 2003; 986:45-53. [PMID: 12585321 DOI: 10.1016/s0021-9673(02)01952-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The retention of D,L-tryptophan enantiomers on an immobilized teicoplanin column was investigated in relation to the mobile phase sodium perchlorate concentration using the perturbation method to determine the solute distribution isotherms. From the experimental data, it appeared that the bi-Langmuir model was able to describe D- and L-enantiomer retention on the immobilized selector over the salt concentration range. An increase in the apparent enantioselectivity with an increase in sodium perchlorate concentration was observed. The chiral recognition enhancement was governed by (i) an increase in the difference of the adsorption constants for binding to the high-affinity site (aglycone pocket) between the two enantiomers and (ii) enhancement of the number of aglycone chiral regions interacting with D-tryptophan. It is suggested that an ion-pair formation mechanism between perchlorate and solute and/or selector is responsible for this behavior. In addition, this work shows that additional secondary sites on the teicoplanin surface are involved in the apparent enantioselectivity at low sodium perchlorate concentrations.
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Affiliation(s)
- Bouchra Loukili
- Equipe de Chimie Analytique, Département de Pharmacochimie Moléculaire, UMR 5063 CNRS-UJF, UFR de Pharmacie de Grenoble, Domaine de la Merci, 38700 La Tronche, France
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Bojarski J. Stereoselective chromatography of cardiovascular drugs: an update. JOURNAL OF BIOCHEMICAL AND BIOPHYSICAL METHODS 2002; 54:197-220. [PMID: 12543499 DOI: 10.1016/s0165-022x(02)00143-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This review reports the latest achievements in chromatographic enantioseparations of various classes of cardiovascular drugs and selected applications of these methods in pharmaceutical and clinical analysis. The use of these drugs as test compounds for new chiral stationary phases and different parameters of chromatographic processes is also presented.
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Affiliation(s)
- Jacek Bojarski
- Department of Organic Chemistry, Medical College, Faculty of Pharmacy, Jagiellonian University, Medyczna 9, 30-688 Cracow, Poland.
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Slama I, Dufresne C, Jourdan E, Fahrat F, Villet A, Ravel A, Grosset C, Peyrin E. Vancomycin dimerization and chiral recognition studied by high-performance liquid chromatography. Anal Chem 2002; 74:5205-11. [PMID: 12403572 DOI: 10.1021/ac0257243] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The retention and separation of D,L-dansylvaline enantiomers (used as test solutes) were investigated using silica gel as stationary phase and vancomycin as chiral mobile-phase additive. A retention model was developed to describe the mechanistic aspects of the interaction between solute and vancomycin in the chromatographic system. It considered the formation of vancomycin dimers both "free" in the mobile phase and adsorbed on silica. By fitting the model equation to experimental data, it appeared clearly that the approach taking into account the vancomycin dimerization described accurately the retention behavior of the compounds. The examination of the model equation parameters showed that the glycopeptide dimerization increased the enantioselectivity by a factor of approximately 3.7. This study demonstrated the preponderant role of the vancomycin dimerization on the chiral recognition process of D,L-dansylvaline. Also, an additional analysis on a vancomycin chiral stationary phase indicated that the addition of vancomycin in the mobile phase promoted a greater enantioselectivity mediated by the formation of dimers in the stationary phase.
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Affiliation(s)
- Ines Slama
- Département de Pharmacochimie Moléculaire, UMR CNRS 5063, UFR de Pharmacie de Grenoble, La Tronche, France
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26
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Nevanen TK, Söderholm L, Kukkonen K, Suortti T, Teerinen T, Linder M, Söderlund H, Teeri TT. Efficient enantioselective separation of drug enantiomers by immobilised antibody fragments. J Chromatogr A 2001; 925:89-97. [PMID: 11519820 DOI: 10.1016/s0021-9673(01)01021-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
There is an increasing need for methods for efficient enantioselective separation and purification of chiral drugs. Genetic engineering provides the means for generating recombinant antibodies exhibiting extremely high specificity for even small molecular mass compounds. Here, recombinant antibody fragments have been generated for the drug diarylalkyltriazole that contains two chiral centres. Immobilised antibody fragments has been used successfully for efficient, step-wise separation of two enantiomers of the drug. Owing to the antibody specificity, one enantiomer came out in the flow-through, while the bound enantiomer could be specifically eluted. One of the antibodies tolerated solvents required both for dissolving the target molecules and for their elution for extended times and was shown to function over multiple cycles of the separation process.
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27
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Jander P, Backovská V, Felinger A. Analysis of the band profiles of the enantiomers of phenylglycine in liquid chromatography on bonded teicoplanin columns using the stochastic theory of chromatography. J Chromatogr A 2001; 919:67-77. [PMID: 11459313 DOI: 10.1016/s0021-9673(01)00783-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The retention behaviour of the enantiomers of underivatized phenylglycine was studied on a Chirobiotic T column packed with amphoteric glycopeptide teicoplanin covalently bonded to the surface of silica gel. The retention and the selectivity of separation of the enantiomers increase with rising concentration of ethanol or of methanol in aqueous-organic mobile phases. The band profiles of the less retained L-phenylglycine are symmetrical, but the band profiles of the more strongly retained D-phenylglycine are tailing in all mobile phases tested. The band broadening does not diminish even at very low concentrations of phenylglycine, so that it cannot be attributed to possible column overload. The analysis of the band profile using the stochastic theory of chromatography suggests that the broadening can be attributed to at least two additional chiral centres of adsorption in the stationary phase contributing to the retention of the more strongly retained enantiomer in addition to the adsorption of the less retained one. This behaviour can be explained by the complex structure of the teicoplanin chiral stationary phase.
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Affiliation(s)
- P Jander
- Department of Analytical Chemistry, University of Pardubice, Czech Republic.
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Ravald L, Fornstedt T. Theoretical study of the accuracy of the elution by characteristic points method for bi-langmuir isotherms. J Chromatogr A 2001; 908:111-30. [PMID: 11218114 DOI: 10.1016/s0021-9673(00)00965-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The bi-Langmuir equation has recently been proven essential to describe chiral chromatographic surfaces and we therefore investigated the accuracy of the elution by characteristic points method (ECP) for estimation of bi-Langmuir isotherm parameters. The ECP calculations was done on elution profiles generated by the equilibrium-dispersive model of chromatography for five different sets of bi-Langmuir parameters. The ECP method generates two different errors; (i) the error of the ECP calculated isotherm and (ii) the model error of the fitting to the ECP isotherm. Both errors decreased with increasing column efficiency. Moreover, the model error was strongly affected by the weight of the bi-Langmuir function fitted. For some bi-Langmuir compositions the error of the ECP calculated isotherm is too large even at high column efficiencies. Guidelines will be given on surface types to be avoided and on column efficiencies and loading factors required for adequate parameter estimations with ECP.
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Affiliation(s)
- L Ravald
- Department of Pharmacy, Uppsala University, Sweden
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