Stereochemical Course of the Biotransformation of Isoprene Monoepoxides and of the Corresponding Diols with Liver Microsomes from Control and Induced Rats
作者:Cinzia Chiappe、Antonietta De Rubertis、Viola Tinagli、Giada Amato、Pier Giovanni Gervasi
DOI:10.1021/tx000061a
日期:2000.9.1
by liver enzymes from control and induced rats has been determined. Between the two primarily formed metabolites, 2-methyl-2-vinyloxirane (2) and isopropenyloxirane (3), epoxide 2 is rapidly transformed into the corresponding vicinal racemic diol 4, predominantly through a nonenzymatic hydrolysis reaction. At variance, epoxide3 is mainly biotransformed into the diol 5 by microsomal epoxide hydrolase
Bacterial Biotransformation of Isoprene and Related Dienes
作者:Derek R. Boyd、David Clarke、Marcel C. Cleij、John T. G Hamilton、Gary N. Sheldrake
DOI:10.1007/s007060070096
日期:2000.6.15
Pseudomonas putida ML 2 was used in the oxidative biodegradation of the acyclic dienes isoprene, trans -piperylene, cis -piperylene, and 1,3-butadiene. Regioselective dioxygenase-catalyzed dihydroxylation of alkenes yielded vicinal diols in the preferred sequence monosubstituted > cis -disubstituted > gem -disubstituted > trans -disubstituted. The isolated diol metabolites had an excess of the R
细菌 恶臭假单胞菌 在无环二烯烃的氧化降解,使用ML 2异戊二烯, 反式 -piperylene, 顺 -piperylene,和1,3-丁二烯。区域选择性双加氧酶催化的烯烃的二羟基化产生邻位二醇,优选的顺序为单取代> 顺式- 二取代> 宝石- 二取代> 反式- 二取代。分离出的二醇代谢物具有过量的 R 构型(9–97% ee ),并通过加入丙二醇作为抑制剂来控制进一步的二醇氧化。使用ML2菌株的立体选择性是由于酶的不对称烯烃二羟基化和二醇的动力学拆分而产生的。 R 构型的烯丙基仲醇基团的对映选择性氧化产生相应的不饱和酮醇 。回收的残留二醇的 S 构型大大过量(≥93% ee ) 。除了产生不饱和二醇和酮醇的酶二烯氧化步骤之外,还发现了酶烯加氢产生饱和酮醇和二醇的证据。
Incorporation of deuterium-labelled analogs of isopentenyl diphosphate for the elucidation of the stereochemistry of rubber biosynthesis
作者:Andrew A. Scholte、John C. Vederas
DOI:10.1039/b515750a
日期:——
prepared to investigate the detailed stereochemicalcourse of addition of C5 units during rubber biosynthesis in Hevea brasiliensis and Parthenium argentatum. These analogs were incorporated into the cis-polyisoprene chain by rubber transferase in rubber particles, and the stereochemistry was determined by 2H-NMR analysis of the polymer or of levulinic acid derivatives obtained from its ozonolytic degradation