水液相下α-丙氨酸Se(Ⅳ)配合物手性翻转的密度泛函理论研究  

Density function theoretical study on the chiral flip ofα-alanine Se(Ⅳ)complex in water-liquid phase environment

作　　者：乔朝阳 刘芳[2] 张雪娇 徐亚华 王旭 杨清荟 杨晓翠[2] 王佐成[2] QIAO Chaoyang;LIU Fang;ZHANG Xuejiao;XU Yahua;WANG Xu;YANG Qinghui;YANG Xiaocui;WANG Zuocheng(College of Computer Science,Baicheng Normal University,Baicheng 137000,China;College of Physics,Baicheng Normal University,Baicheng 137000,China;Department of Cardiology,Baicheng Central Hospital,Baicheng 137000,China)

机构地区：[1]白城师范学院计算机科学学院,吉林白城137000 [2]白城师范学院物理学院,吉林白城137000 [3]白城市中心医院心血管内科,吉林白城137000

出　　处：《中山大学学报（自然科学版）（中英文）》2023年第1期149-160,共12页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：全国大学生创新项目(202110206011);吉林省教育厅科学研究规划项目(JJKH20210010KJ);吉林省科技发展计划自然科学基金(20130101131JC)。

摘　　要：采用密度泛函理论的M06和MN15方法,结合极化连续介质的SMD模型方法,研究了S-α-丙氨酸(S-α-Ala)与4价硒(Se(Ⅳ))配合物(Se(Ⅳ))的手性翻转机理。反应通道研究发现,S-α-Ala·Se(Ⅳ)可在α-H质子只以羰基O作媒介迁移;α-H质子向羰基O迁移后,质子再从氨基N向α-C迁移;质子从质子化氨基向羰基O迁移后,α-H质子再以氨基N作媒介迁移的3个通道上实现手性翻转。势能面计算表明:第3个反应通道最具优势,隐性水溶剂效应下的自由能垒是227.6 kJ/mol,来自于质子从氨基N向α-C迁移的过渡态;显性水溶剂效应下的自由能垒是155.6 kJ/mol,来自于质子从质子化氨基N向羰基O迁移的过渡态。结果表明:水液相下手性α-Ala·Se(Ⅳ)很难消旋,其用于生命体同补α-Ala和Se(Ⅳ)有较好的安全性。The chiral flip mechanism of S-α-alanine(S-α-Ala)and tetravalent selenium(Se(Ⅳ))complexes(S-α-Ala·Se(Ⅳ))was studied by means of M06 and MN15 methods based on density functional theory and SMD model method of polarized continuum.The study of reaction channels shows that S-α-Ala·Se(Ⅳ)can be transferred when the carbonyl O atom as the only medium ofα-H proton;the proton transfers toα-C from amino group N after theα-H proton is transferred to carbonyl O atom;after the proton of protonated amino transfers to carbonyl O atom,α-H proton achieves chiral flip in three channels with amino group N as the medium of protolysis.Investigation on the potential energy surface shows that the third reaction channel has the most advantage,the free energy barrier is 227.6 kJ/mol under the effect of recessive solvent,it comes from the transient state of the proton moving from amino group N toα-C;Under the dominant solvent effect,the free energy barrier is 155.6 kJ/mol,it comes from the transient state of the proton moving from protonated amino group N to carbonyl O atom.The results show that chiralα-Ala·Se(Ⅳ)is difficult to racemize in water-liquid phase,and thus it is relatively safe to be used to supplyα-Ala and Se(Ⅳ)for life simultaneously.

关 键 词：Α-丙氨酸 4价硒 密度泛函理论 手性翻转 能垒 

分 类 号：O641.12[理学—物理化学]