Stereochemical Aspects in the 4-Vinylcyclohexene Biotransformation with Rat Liver Microsomes and Purified Cytochrome P450s: Diepoxide Formation and Hydrolysis
作者:Cinzia Chiappe、Antonietta De Rubertis、Giandomenico Piegari、Giada Amato、Pier Giovanni Gervasi
DOI:10.1021/tx025573z
日期:2003.1.1
Phenobarbital is able to enhance the yield of epoxidation to give preferentially diepoxide (1R, 2S, 4R, 7R)-trans-10b. This enantiomer is also formed as nearly the sole product by P450-catalyzed epoxidation of (1R,2S,4R)-trans-3b, the monoepoxide that, as a consequence of the selective formation from 4-vinylcyclohexene and/or reduced elimination by epoxide hydrolase, tends to accumulate in rat. Also, the P4502B1
已经确定了来自对照和诱导大鼠的肝微粒体以及纯化的P4502B1和P4502E1对4-乙烯基环己烯(2和3)的1,2-单环氧化物(2和3)进行生物转化的立体化学过程。单暴露的顺式-4-乙烯基环己烯1,2-环氧化物(2)和反式-4-乙烯基环己烯1,2-环氧化物(3)的环氧化反应产生了相应的八种异构体双环氧化合物顺式4-乙烯基环己烯双环氧化合物(9)和反式4 -乙烯基环己烯二环氧化合物(10)。此过程的立体选择性受P450诱导的影响。苯巴比妥能够提高环氧化的收率,优先生成二环氧化物(1R,2S,4R,7R)-trans-10b。该对映体几乎也是通过P450催化的(1R,2S,4R)-trans-3b环氧化形成的唯一产物,由4-乙烯基环己烯选择性形成和/或减少的环氧水解酶消除作用的结果是趋于在大鼠中积累。同样,在重构的系统中,P4502B1而非2E1能够进行(1R,2S,4R)-trans-3b的