基于量子化学计算氯霉素降解机理的研究  

Degradation mechanism of chloramphenicol: quantum chemistry computing

作　　者：王译伟[1] 张孝琴[1] 徐昌静 郭建敏[1] 

机构地区：[1]泸州医学院基础医学院,四川泸州646000 [2]泸州医学院药学院,四川泸州646000

出　　处：《化学研究与应用》2016年第1期101-106,共6页Chemical Research and Application

基　　金：四川省科技支撑计划项目(2014SZ0071)资助;四川省科技支撑计划项目(省-市-校联合LY-18)资助;泸州市-泸州医学院联合项目(2013LZLY-J11)资助

摘　　要：采用密度泛函理论(DFT)和二阶微扰理论(MP2)对氯霉素分子降解的微观机理进行了研究。在B3PW91/6-311++G(d,p)和MP2(full)/6-311++G(d,p)水平上,优化了降解过程中所有的反应物、中间体、过渡态和产物的几何构型,并且通过振动频率分析和内禀反应坐标(IRC)跟踪验证了过渡态的正确性。计算所得的成键临界点电荷密度变化也确认了该降解的过程,并找到了五条降解通道。其中生成4-硝基苯甲酸的通道2活化能垒最低,在该降解体系中是较易发生的一条通道。计算结果与试验结果一致,找到降解的速控步骤,对研究合成氯霉素光解抑制剂有重要的指导作用。The degradation mechanism of chloramphenicol has been investigated in detail by using the density functional theory（ DFT） and the second-order Mller-Plesset perturbation theory（ MP2）. At the B3PW91/6-311＋＋（ d,p） and MP2（ full） /6-311＋＋G（ d,p） level of theory,the geometries of all species in the reaction system（ reactants,isomers,transition states and products） were optimized. The transition states were validated by the vibrational frequency analysis and the calculations of the internal reaction coordinate（ IRC）. The reaction processes were confirmed by the changes of charge density at bond-forming critical points; five feasible reaction pathways of this reaction had been found and studied. The results indicated that the pathway which produced 4-nitrobenzoic acid had the lowest activation barrier and it was a competitive pathway that took place easier than others. The computed result is in accordance with the result of test,in addition,the rate-determining step of the degradation benefits to the research for compounding inhibitor.

关 键 词：氯霉素 降解机理 密度泛函理论 二阶微扰理论 

分 类 号：O641[理学—物理化学] R9[理学—化学]