Bile acids: LXI. Synthesis and properties of conjugates of 5α-bile acids.

Allo bile acids and their taurine- and glycine-conjugates were synthesized by modification of existing procedures. Their chromatographic and spectral properties were investigated and compared with the 5β-analogs. Some of the naturally occurring 5α- and 5β-conjugates were separable by high performance liquid chromatography via straight-phase (Corasil II column) or reverse-phase systems (μBondapak/C18 column), though unsuccessful with thin layer or gas liquid chromatography. Differences between the C-5 epimers in the infrared and proton magnetic resonance spectra could be attributed to the configurations at the A/B ring junction and the configuration of the 3-hydroxyl group. The calcium salts of the allo compounds were generally less soluble in water than the 5β-isomers.