A cyclodextrin modified capillary zone electrophoresis (CD-CZE) for the ena
ntiomeric separation of tetrahydroprotoberberine N-metho salts was establis
hed. The resolution was optimized by changing the concentration of the elec
trolyte solution, hydroxypropyl-beta -CD (0.02 M, 0.07 M, or 0.14 M) or dim
ethyl-beta -CD (0.05 M or 0.15 M) in phosphate buffer (pH 2.5 or 3) contain
ing 10% acetonitrile with an applied voltage of 20 kV. This method was appl
ied toward the enantioselective bio-conversion of quaternary tetrahydroprot
oberberine N-metho salts in cultured cells of Corydalis species.