浙江大学学报（理学版）2018，Vol.45Issue(1)：103-111,117,10.DOI:10.3785/j.issn.1008-9497.2018.01.015
组氨酸分子几种稳定构型的手性转变机理及水溶剂化效应
Chiral transition mechanism and water solvation effect of stable configurations of histidine molecules
摘要
Abstract
The chiral transition mechanism and water solvation effect of three kinds of the most stable configurations of histidine molecules were studied by adopting the B3LYP method of density functional theory,the MP2 method of perturbation theory,and smd model method of self consistent reaction field theory.Our study on reaction channels shows that there are three channels a,b and c for the title reaction.For the configuration one and two,the proton of the chiral carbon is transferred directly with amino group as the bridge in the channel a,and in b hydroxyl isomerism firstly,then the proton is transferred with amino group as the bridge,while in c it is transferred with carbonyl/amino groups as the bridge.For the configuration three,the proton is transferred with the following respective groups as the bridge for channels a,b and c:only amino group,carbonyl then amino group,carboxyl then amino group.Calculations of potential energy surface show that channel b is the dominant reaction path in the configuration one and two,step-determining gibbs free energy barriers are 250.8 kJ·mol-1 and 251.7 kJ·mol-1 ,respectively, which are generated by the transition state of proton transfering from the chiral carbon to the amino N after hydroxyl isomerism.In addition,channel a is the dominant reaction path in the configuration three,and step-determining gibbs free energy barrier is 250.8 kJ ·mol-1 that is generated by the transition state of proton transfer from the chiral carbon to the amino N. The water solvation effect reduces the step-determining energy barrier to 109.1 kJ·mol-1 for the dominant reaction path in the configuration one.It shows that water environment has an excellent catalytic effect on the histidine optical isomerization.关键词
组氨酸/手性转变/密度泛函理论/过渡态/微扰理论/自洽反应场Key words
histidine/chiral transition/density functional theory/transition state/perturbation theory/SCRF分类
化学化工引用本文复制引用
王佐成,李晨洁,董丽荣,闫红彦,佟华..组氨酸分子几种稳定构型的手性转变机理及水溶剂化效应[J].浙江大学学报（理学版）,2018,45(1):103-111,117,10.基金项目
吉林省科技发展计划资助项目(20130101131JC （）
20160101308JC). （）
