Effect of molecular structure and conformational change of proline-containing dipeptides in reversed-phase chromatography

Melander, Wayne R.; Jacobson, Jana; Horváth, Csaba

doi:10.1016/s0021-9673(00)81865-8

Cited by 121 publications

(30 citation statements)

References 24 publications

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“…The isomerization barrier of enalaprilat agrees very well with values previously reported in literature determined for other L-peptidyl-L-proline dipeptides [4,7,8,13,50] (DG = < 90 kJ?mol…”

supporting

confidence: 89%

“…As the cis-trans interconversion occurs within the time scale of partitioning, a plateau formation between the two separated peaks of the isomers can be observed. Horvath [4][5][6][7][8][9][10][11] was the first to investigate the isomerization of prolinecontaining peptides during the separation process by NMR, HPLC, and CE experiments. His group estimated isomerization rate constants and the activation barrier of some proline-containing dipeptides by computer-supported Damköhler analysis, a method that is commonly used in chemical engineering.…”

mentioning

confidence: 99%

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Determination of the cis‐trans isomerization barrier of enalaprilat by dynamic capillary electrophoresis and computer simulation

Trapp

Schurig

2004

Electrophoresis

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Dynamic capillary electrophoresis (DCE) and computer simulation of the elution profiles with the stochastic model has been applied to determine the isomerization barriers of the angiotensin converting enzyme inhibitor enalaprilat. The separation of the rotational cis-trans isomeric drug has been performed in an aqueous 20 mM borate buffer at pH 9.3. Interconversion profiles featuring plateau formation and peak broadening were observed. To evaluate the rate constants k(cis-->trans) and k(trans-->cis) of the cis-trans isomerization from the experimental electropherograms obtained by dynamic capillary electrophoresis, elution profiles were analyzed by a simulation with iterative convergence to the experimental data using the ChromWin software which requires the total migration times of the individual isomers t(R), the electroosmotic break-through time t(0), the plateau height h(plateau), the peak widths at half height of the individual isomers w(h), as well as the peak ratio of the isomers as experimental data input. From temperature-dependent measurements between 0 degrees and 15 degrees C the thermodynamic parameters Delta G, Delta H and Delta S, the rate constants k(cis-->trans) and k(trans-->cis) and the kinetic activation parameters Delta G*, Delta H*, and Delta S* of the cis-trans isomerization of enalaprilat were obtained. From the activation parameters the isomerization barriers at 37 degrees C were calculated to be Delta G* (trans-->cis) = 87.2 kJ.mol(-1) and Delta G*(cis-->trans) = 91.9 kJ.mol(-1).

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supporting

confidence: 89%

mentioning

confidence: 99%

Determination of the cis‐trans isomerization barrier of enalaprilat by dynamic capillary electrophoresis and computer simulation

Trapp

Schurig

2004

Electrophoresis

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“…DCE experiments allow investigating the thermodynamics and kinetics in the same experiment [129]. One of the first reports on the isomerization of proteins in CE was published by Hilser and Freire [130], following the investigations of the cis-trans isomerization of proline containing peptides by HPLC by Horváth and coworkers [131][132][133][134] (Fig. 21).…”

Section: Peptides and Proteinsmentioning

confidence: 99%

Investigation of the stereodynamics of molecules and catalyzed reactions by CE

Trapp

2010

Electrophoresis

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The investigation of the molecular dynamics of stereoisomers and the study of the kinetics of reactions, in particular of catalyzed reactions, is of fundamental interest in chemistry, biochemistry, and medicine. Understanding how to control the transition state of a reaction allows for a directed design of new catalysts and benign processes. The integration of reactions and capillary or microchip-based electrophoretic separations is highly attractive to perform on-column derivatizations or enzymatic on-column digests of peptides and proteins for further characterization. The present review article focuses on the recent advances to study the stereodynamics of molecules and reaction kinetics of catalyzed processes by means of CE. Models and algorithms to evaluate interconversion profiles obtained by electrophoretic separation techniques are discussed with respect to the challenging demands of high separation efficiencies typical for electrophoretic techniques. Models used for evaluation are based on iterative computer simulation algorithms using the theoretical plate model or stochastic model of chromatography, empirical calculation methods, derived from equations used in chemical engineering, namely Damköhler analysis, and direct access with the approximation function and more recently with the unified equation, which can be applied to all kinds of first-order reactions taking place during a chromatographic or a electrophoretic separation. Furthermore, areas of applications are presented and discussed to give a guideline for using dynamic CE and on-column reaction electrophoresis to study kinetics of reactions and dynamic processes.

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“…Since the publication of Effect of molecular structure and conformational change of proline-containing dipeptides in reversed phase chromatography in 1982, 69 many articles dealing with interconversion profiles obtained by DHPLC of peptidyl-prolin dipeptides have been published, [70][71][72][73][74][75][76][77] but not in all cases the rate constants of cis-trans isomerization were determined. In 1984, Horváth's group 70 published a theoretical article about the determination of rate constants in dynamic reversed-phase chromatography with the help of the Damköhler number.…”

Section: Liquid Chromatographymentioning

confidence: 99%

Determination of enantiomerization barriers by dynamic and stopped‐flow chromatographic methods

2001

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In recent years, dynamic chromatography and stopped-flow chromatographic techniques have become versatile tools for the determination of enantiomerization and isomerization barriers. Increasing demands for the stereochemical safety of chiral drugs contributed to the rapid development of new techniques. New computer-aided evaluation systems allow the on-line determination of interconversion barriers from the experimental chromatograms. Both dynamic chromatography and stopped-flow chromatography have been applied to the entire range of chromatographic methods (GC, SFC, HPLC, CE).

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Effect of molecular structure and conformational change of proline-containing dipeptides in reversed-phase chromatography

Cited by 121 publications

References 24 publications

Determination of the cis‐trans isomerization barrier of enalaprilat by dynamic capillary electrophoresis and computer simulation

Determination of the cis‐trans isomerization barrier of enalaprilat by dynamic capillary electrophoresis and computer simulation

Investigation of the stereodynamics of molecules and catalyzed reactions by CE

Determination of enantiomerization barriers by dynamic and stopped‐flow chromatographic methods

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