Lipophilicity of selected bile acids as determined by TLC. I

The selected bile acids were chromatographed on RP-HPTLC plates using methanol-water in different volume proportions as mobile phases. The linear relationships were found between R-M values of bile acids and the volume fraction of methanol in the mobile phase. The retention parameters R-MW were extrapolated to zero methanol content and were compared with measured (log P-exp), as well as calculated partition coefficients (IAIogP and logP(Kowin)). It was stated that the investigated bile acids might be considered as compounds belonging to the same group. The most significant correlation was found between the R-MW and logP(Kowin) values. The results indicate that chromatographic R-MW values may be used as a measure of lipophilicity of the investigated bile acids.