Micellar electrokinetic chromatography of highly hydrophobic peptides Original Research Article

A micellar electrokinetic chromatography (MEKC) separation method was developed for analysis of highly hydrophobic derivatized peptides that are able to reverse multidrug resistance (MDR) observed in chemotherapy of human tumors. The hydrophobicity of these peptides was characterized by the retention factor (kMEKC′) obtained by MEKC and by the kHPLC′ obtained by reversed phase high performance liquid chromatography (RP-HPLC). A tendency was observed between the log kMEKC′ values of the peptides investigated and their capabilities to reverse MDR. The higher the kMEKC value of the peptide, the higher its hydrophobicity and the higher was its capability to reverse MDR. This result was in accordance with that obtained by RP-HPLC. Therefore, the effect of the peptides on MDR could be estimated on the basis of their log kMEKC′ values.