Comparative capillary electrophoresis and NMR studies of enantioseparation of dimethindene with cyclodextrins

Chiral recognition of verapamil by cyclodextrins studied with capillary electrophoresis, NMR spectroscopy, and electrospray ionization mass spectrometry

“…Thus, ␤-CD and TM-␤-CD may possess opposite recognition patterns toward the enantiomers of VP. However, as shown in our previous studies 14,38 CICS may not always provide reliable information on the binding priority of the enantiomers. Therefore, the stoichiometry and the binding constants of the intermolecular complexes were determined using Job techniques, respectively.…”

“…12 Further examples are described in the literature. [13][14][15] It is difficult to predict how a given chemical modification affects the multiple forces involved in the intermolecular interactions between CDs and their guests. This knowledge may contribute to the understanding of the nature of the major forces contributing to solute/CD binding and those responsible for stereoselectivity.…”

NMR Spectroscopic Analysis on the Chiral Recognition of Noradrenaline by β-Cyclodextrin ( β-CD) and Carboxymethyl- β-cyclodextrin (CM- β-CD)

“…However, the substituent on the primary rim also is detectable. 24 Based on the 1 : 1 stoichiometry, ROESY spectrum for the complex of CM-β-CD and racemic NA provided the evidence on the bimodal complexation like as the case of the β-CD complex. This result suggested that the ring moiety of partially protonated NA in neutral pH was included at primary or secondary rim into the cavity of CM-β-CD and then simultaneous Coulombic interactions was induced between the amino groups of NA and the carboxyl groups of CM-β-CD.…”

Effect of Urea on the Ion-Association Capillary Electrophoresis Separation of the Anionic Metal Complexes Using Hydrophobic Tetraalkylammonium as Ion-Association Agent

“…It has been shown that urea can be used to improve the separation selectivity in miceller electrokinetic chromatography 10 and electrokinetic chromatography with cyclodextrin. [11][12][13][14][15] Yet, there have been no reports about the use of urea for improving the IA-CE resolution by controlling the ion-association of analytes and the interaction reagent. The fine-tuning of the resolution of IA-CE separation of metal complexes was accomplished as a function of the urea concentration.…”