Comparative enantioseparations with native beta-cyclodextrin and heptakis-(2-O-methyl- 3,6-di-O-sulfo)-beta-cyclodextrin in capillary electrophoresis.
Twenty-three cationic chiral analytes were resolved in capillary electrophoresis using native beta-cyclodextrin and single isomer heptakis-(2-O-methyl-3,6-di-O-sulfo)-beta-cyclodextrin as chiral selectors. For 12 of 16 chiral analytes resolved with both chiral selectors the enantiomer migration order was opposite. In selected cases the structure of cyclodextrin-analyte complexes in aqueous solution was investigated using one-dimensional transverse rotating frame nuclear Overhauser and exchange spectroscopy. It was found that in contrast to mainly inclusion-type complexes between chiral analytes and beta-cyclodextrin, external complexes are formed between the chiral analytes and structurally crowded, highly charged heptakis-(2-O-methyl-3,6-di-O-sulfo)-beta-cyclodextrin.
Institute of Pharmaceutical and Medicinal Chemistry, University of Münster, Münster, Germany. chankve@uni-muenster.de
Bezhan
B
Chankvetadze
Naira
N
Burjanadze
Dawn M
DM
Maynard
Klaus
K
Bergander
Dieter
D
Bergenthal
Gottfried
G
Blaschke
D003505:Cyclodextrins / Q000737:chemistry*; D019075:Electrophoresis, Capillary / Q000379:methods*; D006571:Heterocyclic Compounds / Q000302:isolation & purification; D007202:Indicators and Reagents / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D013057:Spectrum Analysis; D013237:Stereoisomerism; D047392:beta-Cyclodextrins
D003505:Cyclodextrins; D006571:Heterocyclic Compounds; D007202:Indicators and Reagents; D047392:beta-Cyclodextrins; C447199:heptakis(2-O-methyl-3,6-di-O-sulfo)-beta-cyclodextrin; C031215:betadex