Transient state of chiral recognition in a binary mixture of cyclodextrins in capillary electrophoresis

Ding, Yongsheng; Lin, Bingcheng; Jakob, A.; Koppenhoefer, Bernhard

doi:10.1016/s0021-9673(00)00512-4

Cited by 12 publications

(12 citation statements)

References 22 publications

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“…This indicates the reversed migration order of enantiomers in CD2 and CD1. In previous work on enantioseparation in dual chiral selectors giving reversed migration order of enantiomers, a point or CD concentration giving no enantioseparation, Dm = 0 and a = 1.0, is called the transient state [38]. When theoretical k , 1.0, practical k is equal to 1/k.…”

Section: Theoretical Models Of Electrophoretic Mobility Difference Anmentioning

confidence: 99%

Chiral separation in capillary electrophoresis using dual neutral cyclodextrins: Theoretical models of electrophoretic mobility difference and separation selectivity

et al. 2005

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Simple equations and theoretical models, related to enantioselectivity (kappa) and C, have been developed for prediction of electrophoretic mobility difference (Deltamu) and separation selectivity (alpha) for enantiomers in CE using dual CDs, where alpha and kappa are defined as the ratio of mu and the ratio of binding constant (K) for enantiomers to each CD, respectively, C the CD concentration, and the average K for enantiomers and each CD. Experiments were carried out using dual CDs as beta-CD and dimethyl-beta-cyclodextrin (DM-beta-CD) and test analytes as five pairs of amphetamine drug enantiomers. A change in observed Deltamu and alpha of enantiomers in dual CDs was found to be in excellent agreement with the theoretical models. For example, in comparison with single CD1, dual CDs can enhance Deltamu and alpha up to the maximum value when enantiomers migrate with the same order in CD1 and CD2, and have the value of rho > 1.0, where rho is the enantioselectivity ratio for CD2 to CD1, while worse Deltamu and alpha are obtained for enantiomers with rho < 1.0.

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Section: Theoretical Models Of Electrophoretic Mobility Difference Anmentioning

confidence: 99%

Chiral separation in capillary electrophoresis using dual neutral cyclodextrins: Theoretical models of electrophoretic mobility difference and separation selectivity

et al. 2005

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“…While neutral CDs are the most widely used chiral selectors, their separation abilities are limited to only charged species when using CE as the separation technique. Therefore, dual chiral selector systems were introduced to overcome this limitation where neutral CDs were used in combination with other neutral CDs [4], charged CDs [5][6][7][8], and charged micelle surfactants [9][10][11][12][13][14]. Various charged micelle surfactants have been used in CD-MEKC, (e.g., the conventional micelles of sodium dodecyl sulfate (SDS) and bile salts) for the separation of various chiral and achiral compounds.…”

Section: Introductionmentioning

confidence: 99%

Combination of cyclodextrins and polymeric surfactants for chiral separations

et al. 2004

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A cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) method was applied to the enantioseparation of three binaphthyl derivatives using neutral CDs (i.e., beta- and gamma-CD) in combination with various chiral amino acid-based polymeric surfactants (PSs). Both the D- and L-configurations of poly(sodium N-undecanoyl alaninate), poly(sodium N-undecanoyl leucinate), and poly(sodium N-undecanoyl valinate) (poly(L-SUV)) were synthesized. The retention behavior of the three binaphthyl derivatives under optimum electrophoretic conditions using a single chiral additive (PS or CD) is discussed. In addition, the effect of CD cavity size and stereochemical configuration of polymeric surfactants on selectivity (alpha) and resolution (Rs) was investigated. The enantioseparation of (+/-)1,1'-binaphthyl-2,2'-diamine gave a reversal of enantiomeric order when using beta-CD in combination with any of the three D-configuration PS. However, better enantioseparation is obtained when using the corresponding L-configuration PS with beta-CD. A reversal of migration order (RMO) for the enantiomers of (+/-)1,1'-bi-2-naphthol was observed upon the addition of 10 mM gamma-CD to poly(L-SUV). However, no RMO of (+/-)1,1'-bi-2-naphthol was seen when either beta-CD or gamma-CD was combined with D-PS. The enantiomers of (+/-)1,1'-binaphthyl-2,2'-diyl hydrogen phosphate showed little enantioselective behavior toward the PS alone. However, combined D- or L-PS and beta-CD or gamma-CD systems gave increased Rs and alpha values. The chiral recognition of binaphthyl derivatives observed resulting from the various combinations of two chiral selectors is discussed.

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“…In a previous study [35] the combination of two neutral cyclodextrins for the enantioseparation of AGT in pH 2.5 phosphate buffer was investigated and the separation was completely lost upon combination of a-CD and b-CD.…”

Section: Dual Cyclodextrin Systemsmentioning

confidence: 99%

“…Several studies were carried out in order to achieve enantioseparation of AGT; most of them obtained separation of AGT enantiomers using various kinds of chiral selectors in different CE modes [26 -32, 44], in capillary electrochromatography (CEC) [33], as well as in non-aqueous capillary chromatography [34,43]. Zhu et al have studied the transient state of chiral recognition in dual systems utilizing mixtures of neutral cyclodextrins for the enantioseparation of AGT [35]. The chiral resolution of this compound using polymeric chiral surfactants was also examined in micellar electrokinetic chromatography (MEKC), giving rise to some interesting results [36].…”

Section: Introductionmentioning

confidence: 99%

Enantiomeric separation of aminoglutethimide by capillary electrophoresis using native cyclodextrins in single and dual systems

Abushoffa¹,

Fillet

Marini

et al. 2003

J of Separation Science

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Enantiomeric separation of aminoglutethimide by capillary electrophoresis using native cyclodextrins in single and dual systems Aminoglutethimide (AGT) is one of the few examples of chiral drugs that can be enantioseparated by capillary electrophoresis using any of the three native cyclodextrins: a-, b-, or c-CD. A complete resolution of the enantiomers of this compound in cationic form could be achieved with each of the three CDs, using a pH 3 phosphoric acidtriethanolamine buffer. Affinity constants for AGT enantiomers with the three native CDs were determined, confirming that the highest selectivity was given by c-CD while the strongest complexation was obtained with b-CD. However, an opposite affinity pattern was observed with the latter. Selectivity was lower for AGT enantiomers in dual CD systems, compared to that obtained with a single selector at its optimal concentration, which confirms that dual systems are of more limited interest when the two selectors have a similar effect on the analyte mobility. These results are in good agreement with those predicted using recently developed mathematical models.

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Transient state of chiral recognition in a binary mixture of cyclodextrins in capillary electrophoresis

Cited by 12 publications

References 22 publications

Chiral separation in capillary electrophoresis using dual neutral cyclodextrins: Theoretical models of electrophoretic mobility difference and separation selectivity

Chiral separation in capillary electrophoresis using dual neutral cyclodextrins: Theoretical models of electrophoretic mobility difference and separation selectivity

Combination of cyclodextrins and polymeric surfactants for chiral separations

Enantiomeric separation of aminoglutethimide by capillary electrophoresis using native cyclodextrins in single and dual systems

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