Comparative studies of bile salts. Bile salts of the lamprey Petromyzon marinus L.

Abstract

1. Bile salts of Petromyzon marinus L. ammocoetes appeared to consist solely or chiefly of a crystalline substance, whose chromatographic and i.r.-spectral characteristics suggested that it was a monosulphate ester of a bile alcohol having the 3α,7α,12α-trihydroxy pattern of substitution in a 5α-steroid nucleus. 2. This substance on cleavage with dioxan–trichloroacetic acid gave petromyzonol, n.m.r. and mass-spectral examination of which suggested the structure 5α-cholane-3α,7α,12α,24-tetrol. 3. 3α,7α,12α-Trihydroxy-5α-cholanoic acid (allocholic acid) from the lizards Anolis lineatopus lineatopus Gray and Cyclura carinata Harlan (family Iguanidae) was esterified with propan-1-ol and reduced by lithium aluminium hydride to 5α-cholane-3α,7α,12α,24-tetrol, identical with petromyzonol. 4. Chromic acid oxidation of petromyzonol sulphate from lamprey bile, followed by acid hydrolysis, gave 24-hydroxy-5α-cholane-3,7,12-trione; hence the sulphate ester group is at C-24. 5. Petromyzonol sulphate is both primitive and unique: a study of its biogenesis might improve our understanding of evolution at the molecular level.