Stereochemical Aspects in the 4-Vinylcyclohexene Biotransformation with Rat Liver Microsomes and Purified P450s. Monoepoxides and Diols
作者:Cinzia Chiappe、Antonietta De Rubertis、Massimiliano De Carlo、Giada Amato、Pier Giovanni Gervasi
DOI:10.1021/tx000255q
日期:2001.5.1
biotransformed into the corresponding vicinal diols by mEH-catalyzed hydrolysis. The reaction of the endocyclic epoxides occurred with good substrate diastereo- and enantioselectivity favoring the hydrolysis of epoxides (1S,2R,4S)-3 and (1R,2S,4S)-2 to give, before 50% conversion, selectively (1R,2R,4S)-diol (6). At variance, the hydrolysis of the exocyclic epoxides was characterized by a high level of substrate
已经确定了肝微粒体从雄性和雌性对照以及诱导的大鼠和纯化的大鼠P450 2B1和2E1进行的肝微粒体对4-乙烯基环己烯(VCH,1)进行生物转化的立体化学过程。雄性微粒体催化的1的环氧化作用在环内和环外双键上均产生四个异构体环氧化物,顺式4-乙烯基环己烯1,2-环氧化物(2),反式4-乙烯基环己烯1,2-环氧化物(3),(4R *,7S *)-4-乙烯基环己烯7,8-环氧化物(4)和(4R *,7R *)-4-乙烯基环己烯7,8-环氧(5)。另一方面,来自雌性大鼠的微粒体主要催化环内环氧化。该过程的立体选择性在很大程度上取决于性别和P450的诱导。只有较低浓度的苯巴比妥和吡唑能够增强1的环氧化作用,并且大多数情况下能够增强内环双键。也,重构系统中的P450 2E1和2B1能够主要在其环内双键上进行1的环氧化。代谢物顺式和反式-4-乙烯基环己烯1,2-环氧化物(分别为2和3)和异构体4-乙烯基环己烯7