The Formation of Bile Acids from Cholesterol

Abstract

Abstract The synthesis of 5β-cholestane-3α,7α,12α,24ξ-tetraol-26-oic acid-14C and the separation of 5β-cholestane-3α,7α,-12α,24ξ-tetraol-26-oic acids I and II are described. The conversion of 5β-cholestane-3α,7α,12α-triol-26-oicacid to 5β-cholestane-3α,7α,12α,24ξ-tetraol-26-oic acid I was catalyzed by rat liver mitochondria supplemented with 105,000 x g supernatant fraction, adenosine triphosphate, MgCl2, flavin adenine dinucleotide, and coenzyme A. Cell fractionation and requirement of cofactors for the same reaction were examined. 5β-Cholestane-3α,7α,12α,24ξ-tetraol-26-oic acid I which was derived from the incubation of 5β-cholestane-3α,7α,12α-triol-26-oic acid was further oxidized to cholic acid with 105,000 x g supernatant fraction of rat liver, ATP, MgCl2, glutathione, nicotinamide adenine dinucleotide, and CoA. The conversion of synthetic 5β-cholestane-3α,7α,12α,24ξ-tetraol-26-oic acid-14C was examined with the use of different cell fractions of rat liver. The formation of cholic acid from 5β-cholestane-3α,7α,12α,24ξ-tetraol-26-oic acid was catalyzed by either mitochondria or 105,000 x g supernatant with NAD+ or NADP+.