Goto J, Miura H, Ando M, Yamato Y, Ikegawa S, Nambara T, Makino I
Faculty of Pharmaceutical Sciences, Tohoku University, Aobayama, Sendai, Japan.
Steroids. 1996 Jul;61(7):416-20. doi: 10.1016/0039-128x(96)00061-x.
7 alpha,12 alpha-Dihydroxy-3-oxo- and 3,7,12-trioxo-5 beta-cholanoic acids labeled with 18O atoms were incubated with human red blood cells, and the biotransformation products were separated and characterized by gas chromatography-mass spectrometry as the pentafluorobenzyl ester-trimethylsilyl and -dimethylethylsilyl ether derivatives with the negative ion chemical ionization mode. The reduced products, 3 beta,7 alpha,12 alpha-trihydroxy-5 beta-cholanoic acid for the former, and 3 alpha-hydroxylated dioxo bile acid together with 3 beta-hydroxylated 7,12-dioxo-5 beta-cholanoic acid for the latter, were identified as metabolites. When 3-oxo bile acid was incubated with human blood denatured at 70 degrees C for 2 min, no metabolites were formed. The enzymic reduction activity has been localized in the red blood cell fraction.
将用(^{18}O)原子标记的7α,12α-二羟基-3-氧代和3,7,12-三氧代-5β-胆烷酸与人红细胞一起孵育，生物转化产物通过气相色谱-质谱法分离并表征为五氟苄基酯-三甲基硅烷基和-二甲基乙基硅烷基醚衍生物，采用负离子化学电离模式。还原产物，前者为3β,7α,12α-三羟基-5β-胆烷酸，后者为3α-羟基化二氧代胆汁酸以及3β-羟基化的7,12-二氧代-5β-胆烷酸，被鉴定为代谢物。当3-氧代胆汁酸与在70℃变性2分钟的人血一起孵育时，未形成代谢物。酶促还原活性已定位在红细胞部分。
