Comparative Study of the Lipophilicity of Selected Tauro-Conjugates Bile Acids Determined with the Use of RPTLC and RPHPTLC Methods

Abstract

Lipophilicity of selected tauro-conjugates bile acids such as: taurocholic acid (TC), taurodeoxycholic acid (TDC), taurochenodeoxycholic acid (TCDC), and taurolithocholic acid (TLC), by means of RPTLC and RPHPTLC methods was found. Reversed–phase thin layer chromatography was performed on RP18F₂₅₄, RP18WF₂₅₄, and on RP2F₂₅₄ chromatographic plates with the use of a mixture of an organic modifier (methanol, acetone, dioxane)–water in different volume compositions. The obtained chromatographic parameters of lipophilicity (R_MW and ϕ₀) indicates that regardless of applied chromatographic conditions, the lipophilicity of four examined tauro-conjugates bile acids should decrease in the following order: TLC > TCDC ≅ TDC > TC. A good correspondence between experimentally determined lipophilic parameters and the theoretical value of lipophilicity (log P_virtual) for investigated bile acids was observed. The cluster analysis (CA) of lipophilic parameters indicates a large similarity of lipophilicity for tauro-conjugates bile acids. All examined bile acids form exactly one cluster in almost all chromatographic systems used.

Keywords:

• Bile acids
• Lipophilicity
• log P
• RPTLC

ACKNOWLEDGMENT

This research was financed by Silesian University of Medicine.

Notes

Note. n-number of points used to derive the particular regressions; r-correlation coefficient; s-standard error; F-value of Fisher test.

^a For all equations the significance level p < 0.001.

Note. n-number of points used to derive the particular regressions; r-correlation coefficient; s-standard error; F-value of Fisher test.

^a For all equations the significance level p < 0.0001.

Note. n-number of points used to derive the particular regressions; r-correlation coefficient; s-standard error; F-value of Fisher test.

^a For all equations the significance level p < 0.0001.

Note. r–correlation coefficient; s-standard error; F-value of Fisher test; p-significance level –methanol-water; a–acetone—water; d-dioxane-water.

Note. m-methanol-water; a-acetone–water; d-dioxane-water.