Resolution of enantiomeric N-oxides by capillary electrophoresis using cyclodextrins as chiral selectors

The resolution of a series of rac-N-alkyl-N-methylaniline N-oxides and parg yline N-oxide (PNO) has been examined by capillary electrophoresis (CF) usi ng both native and derivatised beta-cyclodextrins (beta-CD) as chiral selec tors. Resolution of the six analytes examined was achieved using either hyd roxyethyl- or methyl-beta-CD. The electrophoretic migration order of PNO wa s confirmed to be (-) before (+) by the use of single enantiomers obtained by semi-preparative chromatography. The chiral CE methodology developed for the separation of the enantiomers of PNO was superior to the previously re ported high performance liquid chromatographic method using a chiral statio nary phase (CSP), both in terms of analysis time and resolution. The develo ped methodology was employed to further examine the stereoselective flavin- containing monooxygenase (FMO) mediated N-oxidation of pargyline. Chirality 11:409-415, 1999. (C) 1999 Wiley-Liss, Inc.