Isolation and purification of lithocholic acid metabolites produced by the intestinal microflora.

Lithocholic acid metabolites produced by the intestinal microflora of rats can be isolated from other endogenous lipids using Sephadex LH-20 column chromatography. Analyses of individual metabolites collected from the column by silica gel coated glass fiber paper chromatography result in the resolution of epimeric 3-hydroxy derivatives. In addition, glass fiber paper chromatography is more sensitive and requires less development time than conventional glass-coated thin-layer plates. Further confirmation of the identity of metabolites is achieved by gas-liquid chromatography, which separates both methyl and ethyl esters of lithocholic and isolithocholic acids.