摘要
用ab initio方法,在MP2/6-31G**水平下讨论了α-乙酰氧基-亚硝基吡咯烷(α-Acetoxy-NPYR)在各种条件下的解离反应机理,并对形成终致癌物B,C,D的代谢机理进行研究.发现在OH-和H2O作用下的解离都遵循羟基进攻羰基机理,OH-作用下是一个经四面体中间体阴离子的无位垒过程,H2O作用下有相对高的活化能(165.36kJ/mol).H3O+作用下是先形成阳离子产物的SN1过程,并没有发现遵循两种综合的解离情形.同时,羟基化产物异构化为终致癌物B,C,D是一个相对容易进行的过程.
The decomposition mechanism of α-acetoxy-N-nitrosopyrrolidine has been theoretically investigated at the MP2/6-31G** level in various environments (OH^-, H2O, H3O^+). It was found that the decomposition mediated by OH^- and H2O was a "typical" carbonyl attack mechanism of ester hydrolysis. In the presence of H3O^+, the decomposition is an SN1 process via an intermediate of N-nitrosiminium ion. A mixture of the carbonyl attack mechanism and SN1 process was found. The unstable decomposed product of α-hydroxy-nitrosopyrrolidine can be metabolized into active carcinogenic metabolites of B, C, and D, and the process involving isomerization and protonation is easy to occur.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2007年第15期1459-1463,共5页
Acta Chimica Sinica