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Resolution of ephedrine derivatives by means of neutral and sulfated heptakis (2,3‐di‐ O ‐acetyl)β‐cyclodextrins using capillary electrophoresis and nuclear magnetic resonance spectroscopy
Author(s) -
Wedig Maike,
Holzgrabe Ulrike
Publication year - 1999
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/(sici)1522-2683(19990901)20:13<2698::aid-elps2698>3.0.co;2-n
Subject(s) - chemistry , cyclodextrin , ephedrine , capillary electrophoresis , beta (programming language) , beta cyclodextrins , stoichiometry , enantiomer , spectroscopy , pseudoephedrine , chromatography , stereochemistry , physics , quantum mechanics , neuroscience , computer science , biology , programming language
β‒Cyclodextrin (β‒CD), heptakis(2,3‒di‒ O ‒acetyl)β‒cyclodextrin (Diac‒β‒CD) and heptakis (2,3‒di‒ O ‒acetyl‒6‒sulfato)β‒cyclodextrin (HDAS‒β‒CD) were tested for their ability to discriminate the enantiomers of ephedrine, pseudoephedrine, norephedrine and methylephedrine. Using capillary electrophoresis (CE) under optimized conditions, with the exception of norephedrine in presence of β‒CD, all racemates could be resolved. Utilizing Job's plot by means of UV spectroscopy revealed 1:1 complexes formed with β‒CD and Diac‒β‒CD. HDAS‒β‒CD gave curved plots indicating mixed stoichiometry. Inspection of the cyclodextrin‒induced chemical shifts (CICS) of both the ligands and the CDs showed that the ephedrine sits deeply in the cavity of β‒CD and HDAS‒β‒CD. In the case of Diac‒β‒CD, the ephedrine is located closely to the wider rim of the CD cavity. In conclusion, comparing the pattern of CICS of the various CD derivatives clearly indicates the differences in the complex geometry.