Methoxyethylammonium monosubstituted β-cyclodextrin as the chiral selector for enantioseparation in capillary electrophoresis

Methoxyethylamine monosubstituted β-cyclodextrin, mono-6A-(2-methoxyethyl-1-ammonium)-6A-β-cyclodextrin chloride (MEtAMCD), is synthesized and analytically characterized. Bearing a methoxy group in cyclodextrin rim, MEtAMCD exhibits outstanding enantioselectivities toward ampholytic and acidic racemates in capillary electrophoresis. Driven by inclusion complexation, electrostatic interactions and/or hydrogen bonding, the enantioseparation of MEtAMCD is found to be strongly dependent on various separation parameters including buffer pH, cyclodextrin concentration, applied voltage, separation temperature and organic solvent additives. MEtAMCD demonstrates as a versatile cationic chiral selector for the studied 26 acidic and ampholytic enantiomers.

► The synthesis of methoxylamine monosubstituted cyclodextrin (CD) as chiral selector.
► The outstanding enantioseparation abilities toward acidic, ampholytic and even neutral racemates.
► The chiral resolutions of 20 racemates with 2.5 mM CD.
► Full optimization of separation conditions.