Determination of the lipophilicity of 2'-hydroxychalcones by RP HPLC method

Abstract

Lipophilicity of twelve synthesized chalcones, whose ring B is a ortho, meta or para monosubstituted with alkyl, oxyalkyl groups or halogens was determined by reverse phase liquid chromatography, using octadecyl-functionalized (RP-18) silica gel as a stationary phase and two-component mixture of methanol/water as a mobile phase. Linear dependence of logk? values of the volume fraction of methanol in the mobile phase was determined for all analyzed compounds, with high coefficient of correlation (r > 0.99). Extrapolation of the line to 0% methanol concentration resulted in the capacity factor of chromatographic system where water is the mobile phase (logkw). For five standard substances, chemically similar to chalcones, logkw values were determined under experimental conditions and they were correlated with logP values of those compounds available in the literature. logPEXP values of synthesized chalcones were calculated on the basis of the created standard curve. In order to estimate the relevance of the experimentally obtained logP values for chalcones, correlation of logPEXP values with the logP values obtained through various computational procedures was performed using linear regression analysis. Statistical parameters of dependence showed that the best matching of the results had been achieved with ChemOffice program, suggesting that this program is suitable for calculating logP values of newly-synthesized chalcones, as well as of compounds structurally similar to chalcones.