Separation of aldose enantiomers by capillary electrophoresis in the presence of optically active N-dodecoxycarbonylvalines

The 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatives of aldose enantiomers were well separated from each other by capillary zone electrophoresis using a neutral phosphate buffer containing an optically active N-dodecoxycarbonylvaline (DCV). The L-enantiomers migrated first and the D-enantiomers followed, when R-DCV was added to electrophoretic solution, and the migration order was reversed for the addition of S-DCV. This separation was inherent to PMP derivatives; other derivatives such as 2-aminopyridine, 8-aminonaphthalene-1,3,6-trisulfonate and 4-nitrobenz-2-oxa-1,3-diazole-tagged glycamine derivatives were not separated at all. L-Lauroylvaline and sodium dodecyl sulfate were also not separated. Based on these results, together with the H-1 NMR signal change (upfield shift of the carbohydrate-proton signals in PMP-aldoses) on addition of R-DCV, we speculated this separation to be due to the difference in the ease of intermolecular ring formation by hydrogen bonding. (C) 1997 Elsevier Science B.V.