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Use of a zwitterionic cyclodextrin as a chiral agent for the separation of enantiomers by capillary electrophoresis
Author(s) -
Lelièvre Frédéric,
Gueit Carole,
Gareil Pierre,
Bahaddi Youssef,
Galons Hervé
Publication year - 1997
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.1150180607
Subject(s) - capillary electrophoresis , enantiomer , cyclodextrin , chromatography , chemistry , electrophoresis , combinatorial chemistry , organic chemistry
The purity and enantioselectivity of a novel chiral agent, the zwitterionic mono‐(6‐δ‐glutamylamino‐6‐deoxy)‐β‐cyclodextrin (β‐CD‐Glu), were studied by capillary electrophoresis. Chiral separation of the enantiomers of chlorthalidone was obtained at pH 2.3, a pH at which β‐CD‐Glu is partially protonated. Comparison with the cationic mono‐(6‐amino‐6‐deoxy)‐β‐cyclodextrin (β‐CD‐NH2) enantioselectivity clearly shows that the greater the difference in mobility between the free analyte and the analyte‐cyclodextrin complex, the better the resolution. Hydrobenzoin enantiomers were separated at pH 11.2, a pH at which β‐CD‐Glu is anionic. Under these conditions, the migration order was opposite to that observed in the presence of β‐CD‐NH2 at pH 2.3. When no separation was obtained directly with β‐CD‐Glu, a dual cyclodextrin system was developed. Carprofen enantiomers were resolved at pH 2.3 in the presence of a β‐CD‐Glu/trimethyl‐β‐cyclodextrin (TM‐β‐CD) system in which the charged CD confers a non‐zero mobility to the analyte, while the neutral CD allows chiral recognition.