Enantiomer discrimination by mass spectrometry: noncovalent interactions of an N-derivatized dipeptide with various cinchona alkaloid derivatives and comparison with enantioselective liquid-phase separations.
The enantiomer discrimination properties of cinchona alkaloid derived chiral selectors (CSs) towards a dipeptide analyte are examined by electrospray ionization mass spectrometry. The complexes formed between the CSs and the analyte enantiomers owing to various noncovalent interactions are analyzed and the magnitudes of enantiomer discrimination are determined from the complexes' mass spectrometric intensities. The influence of different structural features of the CSs on enantioselectivity is discussed. The enantiomer discrimination results obtained by mass spectrometry are compared with those from related liquid chromatography enantiomer separations. A certain coherence between the chromatographic and mass spectrometric enantioselectivities could be established and the enantiomer discrimination patterns, i.e., the relative binding strengths, were identical for the two techniques. Thus, the use of mass spectrometry as a screening tool in the development of new CSs for chromatographic applications seems feasible.
Czerwenka
Christoph
C
Institute of Analytical Chemistry, University of Vienna, Währingerstrasse 38, 1090 Vienna, Austria.
Maier
Norbert M
NM
Lindner
Wolfgang
W
D002853:Chromatography, Liquid / Q000379:methods; D002930:Cinchona Alkaloids / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D011485:Protein Binding; D013237:Stereoisomerism
D002930:Cinchona Alkaloids; D010455:Peptides