Batta A K, Salen G, Arora R, Shefer S, Batta M, Person A
Department of Medicine, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark 07103.
J Biol Chem. 1990 Jul 5;265(19):10925-8.
The effect of side chain conjugation on 7-dehydroxylation of bile acids has been investigated. C24-bile acids and their glycine and taurine conjugates and keto bile acids were incubated with pure strains of Eubacterium sp. VPI 12708. Bile acids of the 5 alpha- or 5 beta-series with a free terminal carboxyl group and a 3 alpha, 7 alpha-dihydroxy system were very effectively 7 alpha-dehydroxylated, whereas 7 beta-hydroxy bile acids resisted 7-dehydroxylation. Oxo bile acids were metabolized at the oxygen function also. Glycine- and taurine-conjugated bile acids were neither deamidated nor 7-dehydroxylated by the bacteria. Thus, side chain conjugation prevents 7-dehydroxylation of bile acids by Eubacterium sp. VPI 12708.
已对侧链共轭对胆汁酸7-脱羟基作用的影响进行了研究。将C24-胆汁酸及其甘氨酸和牛磺酸共轭物以及酮胆汁酸与真杆菌属VPI 12708的纯菌株一起孵育。具有游离末端羧基和3α，7α-二羟基系统的5α-或5β-系列胆汁酸非常有效地进行了7α-脱羟基，而7β-羟基胆汁酸则抵抗7-脱羟基。氧代胆汁酸在氧官能团处也被代谢。细菌既不会使甘氨酸和牛磺酸共轭的胆汁酸脱酰胺，也不会使其7-脱羟基。因此，侧链共轭可防止真杆菌属VPI 12708对胆汁酸进行7-脱羟基。
