New challenge in the lipophilicity determination and separation of biologically active 16,17-secoesterone derivatives by HPLC – Use of pentafluorophenyl-propyl column

Abstract

The retention behavior, lipophilicity of 16,17-secoestrone derivatives and efficiency in the separation of halogenated derivatives by HPLC with pentafluorophenyl-propyl stationary phase (F5) were studied. Methanol-water (MeOH-W) and acetonitrile-water (ACN-W) were used as mobile phases in proportions according to nomograph of iso-eluotropic binary solvent mixtures. Since mobile phase ACN-W was more effective eluent, the retention behavior of 16,17-secoesterone derivatives has further been evaluated, with water content increasing in increments of 5%. The retention constants log k for mobile phases MeOH-W and ACN-W, have been compared by applying Student’s paired t-test and Fisher’s F-test to determine the applicability of the nomograph to this column. Linear correlations were obtained between parameters log k0 and log P, as well as φ0 and log P, for both MeOH-W and ACN-W eluents. Compared with log k0, the hydrophobicity index φ0 proved to be better parameter for lipophylicity estimation of these compounds. According to the separation efficacy of individual components, as well as mixtures of halogenated secoestone compounds, chromatographic columns can be placed in the following order: C18> F5> C8. This result is of huge importance for the field of synthesis, purification and characterization of novel biologically and pharmacologically active compounds and steroids among them.