Chiral Recognition And Binding Constant Determination In Monovalent And Bivalent Systems Using Electrospray Ionization Mass Spectrometry

Electrospray ionization mass spectrometry (ESI-MS) is a soft ionization method which is capable of transferring weakly bound host-guest noncovalent complexes from the solution phase to the gas phase. This capability makes ESI-MS an ideal tool for the quantification of binding affinities of different host-guest noncovalent complexes. There is a growing interest in using ESI-MS for chiral recognition studies. In thiswork ESI-MS was employed to investiga te the binding affinities for cinchona alkaloid chiral selectors binding N-blocked leucine enantiomers, as well as for macrocyclic antibiotics binding a variety of derivatized and underivatized amino acids. The effect of multivalency on binding affinity was also evaluated. This ESI-MS method is very promising for the binding studies of different host-guest systems. Merits of this method are speed, sensitivity and low sample consumption.