Bile salts of the toad, Bufo marinus: characterization of a new unsaturated higher bile acid, 3 alpha,7 alpha,12 alpha,26-tetrahydroxy-5 beta-cholest-23-en-27-oic acid.

Abstract

The bile salts present in gallbladder bile of the toad, Bufo marinus, were found to consist of a mixture of bile alcohol sulfates and unconjugated bile acids. The major bile alcohol was 5 beta-bufol; 5 alpha- and 5 beta-cholestane-3 alpha,7 alpha,12 alpha, 26-tetrols occurred as the minor bile alcohols. Bile acids of Bufo marinus were cholic acid, allocholic acid, 3 alpha,7 alpha,12 alpha-trihydroxy-5 alpha- and 5 beta-cholestan-26-oic acids, 3 alpha,7 alpha,12 alpha-trihydroxy-5 alpha- and 5 beta-cholest-23-en-26-oic acids, 3 alpha,7 alpha,12 alpha, 26-tetrahydroxy-5 beta-cholestan-27-oic acid, and a C27 bile acid which has not been previously described. By chromatographic behavior, mass spectral data, and identification of the products of catalytic hydrogenation and ozonolysis, the structure of the new higher bile acid was elucidated as 3 alpha,7 alpha,12 alpha,26-tetrahydroxy-5 beta-cholest-23-en-27-oic acid. The bile salt pattern of Bufo marinus closely resembles that of Bufo vulgaris formosus, except for the absence of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholest-22-ene-24-carboxylic acid, the major bile acid of the latter toad.