The separation of isomers of camptothecin synthetic intermediate, ethyl 2-[N-p-tosyl-(R)-proli- noyl]-2-[6-cyano-(1,1-ethylenedioxy)-5-one-1,2,3,9-tetrahydroindolizine-7-yl]butyrate, on CHI-DMB and (R,R)-DNB-DPEDA chiral columns was firstly reported. The influence of the alcoholic modifiers in mobile phase, including kinds and the concentration on the separation was studied. The separation mechanism of the analyte on the two chiral columns was also investigated and it was found that the attractive interaction between the analyte and the chiral stationary phase (CSP) played the predominant role on both CSPs. Consulted from the interactions between the CSP and the analyte, π-π stacking and dipole-dipole interactions acted on CHI-DMB chiral column while π-π stacking, dipole-dipole interaction and the hydrogen bonding worked on (R,R)-DNB-DPEDA chiral column. Besides these, the steric bulk was also important for the separation of the isomers of camptothecin synthetic intermediate. A rational correlation was found between elution order and absolute configuration of the analyte. The elution order was confirmed by corresponding isomer.

Key words: CHI-DMB, (R,R)-DNB-DPEDA, separation of optical isomers, camptothecin synthetic intermediate, chiral recognition mechanis