MICELLAR ELECTROKINETIC CHROMATOGRAPHY OF THE ANTI-HUMAN-IMMUNODEFICIENCY-VIRUS (HIV) AGENT MICHELLAMINE-B WITH ABSORPTION AND LASER-INDUCED FLUORESCENCE DETECTION

Micellar electrokinetic chromatography (MEKC) was applied to the separ ation of the anti-HIV agents, michellamines A and B, and two other str ucturally related monomers found in the extract of the Ancistrocladus plants. Using buffers containing either 10 mM sodium phosphate (pH 7.0 ), 50 mM sodium deoxycholate and 10-20% acetonitrile or 5 mM sodium ph osphate (pH 7.0), 20 mM sodium dodecyl sulfate and 25% acetonitrile al lowed baseline separations of the four components in the mixture in le ss than 10 min. The MEKC methods gave sharper peaks and better resolut ion compared to high-performance liquid chromatography. For MEKC separ ation of the plant extracts, UV absorption detection provided adequate sensitivity; however, higher sensitivity could be achieved with UV la ser-induced fluorescence detection (LIF). Using the sodium dodecyl sul fate-containing buffer and LIF, the limit of detection for michellamin e B was similar to 2 ng/mL. The sensitivity was degraded similar to 10 0-fold when using the deoxycholate buffer because of high background f luorescence. Preliminary results show that MEKC with LIF is feasible f or the sensitive detection of michellamine B in serum.