Chiral separation of 12 pairs of enantiomers by capillary electrophoresis using heptakis-(2,3-diacetyl-6-sulfato)-β-cyclodextrin as the chiral selector and the elucidation of the chiral recognition mechanism by computational methods

Abstract

Chiral separation of 12 pairs of basic analyte enantiomers including oxybutynin, bambuterol, tradinterol, clenbuterol, clorprenaline, terbutaline, tulobuterol, citalopram, phencynonate, fexofenadine, salbutamol, and penehyclidine was conducted by capillary electrophoresis using a single-isomer anionic β-cyclodextrin derivative, heptakis-(2,3-diacetyl-6-sulfato)-β-cyclodextrin as the chiral selector. Parameters influencing separation were studied, including background electrolyte pH, heptakis-(2,3-diacetyl-6-sulfato)-β-cyclodextrin concentration, buffer concentration, and separation voltage. A background electrolyte consisting of 50 mM Tris-H PO and 6 mM heptakis-(2,3-diacetyl-6-sulfato)-β-cyclodextrin at pH 2.5 was found to be highly efficient for the separation of most enantiomers, with other conditions of normal polarity mode at 10 kV, detection wavelength of 210 nm using hydrodynamic injection for 3 s. Under the optimal conditions, baseline resolution (>1.50) for 11 pairs of enantiomers and somewhat lower resolution for penehyclidine enantiomers (1.17) were generated. Moreover, the possible mechanism of separation of clenbuterol, oxybutynin, salbutamol, and penehyclidine was investigated using a computational modeling method.

Synergistic enantioseparation systems with either cyclodextrins or cyclofructans and L‐alanineTertbutyl ester lactate

“…On the other hand, the chiral ionic liquid, which, in most cases, improves both efficiency and resolution significantly, is simple and cheap to synthesize . In addition, the analysis times of NEF , FXD , WAR , and COU were sufficiently lower than the ones reported in the literature.…”

Chiral Separations by Capillary Electrophoresis and related Techniques with Different Chiral Selectors: A Review

“…In another study, heptakis-(2,3diacetyl-6-sulfato)-β-cyclodextrin was applied as the chiral selector on separations of 12 pairs of basic analyte enantiomers some of including oxybutynin, bambuterol, tradinterol, clenbuterol. Conditions of the study applied at pH 2.5 were found to be highly efficient for the separation of most enantiomers with normal polarity mode at 10 kV [187]. Maltodextrin (MD) as a linear polysaccharide can be considered as a chiral selector for chiral separation of a wide variety of acidic and basic compounds in CE system with high efficiency [188].…”

Chiral Selectors in Capillary Electrophoresis: Trends during 2017–2018

“…β-CD derivatives, i.e., neutral (hydroxyethyl-, hydroxypropyl- and methyl-) and anionic (carboxymethyl-, and sulphated-) [21,22,23,24,25,26,27,28,29,30,31,32,33] derivatives were the most commonly used CSs reported. Other commercially-available modified CDs or laboratory-prepared modified CDs with known synthesis were reported.…”

“…Molecular modelling can help the researcher understand the different steps involved in the molecular recognition process, the non-bonding interactions involved between the analyte and the CS and the binding energies for their association. During this review period, ten studies utilised molecular modelling, with the intention of understanding chiral recognition mechanism and elution migration order [22,32,35,44,60,62,72,73,94,95]. Molecular modelling has also been utilised to design new CSs [40].…”