水溶液环境下手性配合物Phe·Ca^(2+)对映异构机理的DFT研究  

The DFT study on the isomerization mechanism of chiral complexes Phe·Ca^(2+)in aqueous solution

作　　者：赵丽红[1] 彭国强 郝成欣[1] 苏丹[1] 姜春旭 王佐成[2] ZHAO Lihong;PENG Guoqiang;HAO Chengxin;SU Dan;JIANG Chunxu;WANG Zuocheng(College of Basic Medicine,Baicheng Medical College,Baicheng 137000,China;Theoretical Computing Center,Baicheng Normal University,Baicheng 137000,China)

机构地区：[1]白城医学高等专科学校基础医学院,吉林白城137000 [2]白城师范学院理论计算中心,吉林白城137000

出　　处：《中山大学学报（自然科学版）（中英文）》2023年第6期50-60,共11页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：白城医学高等专科学校科研平台项目(BYZK202222);白城医学高等专科学校高层次人才团队建设项目(BCYZ20220408);吉林省科技发展计划自然科学基金(20160101308C)。

摘　　要：采用DFT(density functional theory)的M06-2X、MN15方法和处理溶剂效应的SMD模型方法,研究了水溶液中S-苯丙氨酸(S-Phe)与二价钙(Ca^(2+))配合物(Phe·Ca^(2+))的对映异构。反应通道研究发现,S-Phe·Ca^(2+)的对映异构可在质子以N和O分别为桥以及O和N联合为桥迁移的3个通道上实现。计算表明:最优势通道是质子以N为桥迁移,隐性水溶剂效应下决速步自由能垒是227.5 kJ/mol,显性水溶剂效应下该能垒降至108.0~117.6 kJ/mol。结果表明:水溶液中手性Phe·Ca^(2+)的消旋过程十分缓慢,将其用于生命体同补苯丙氨酸和钙元素可能比较安全。The enantiomerism of amphoteric phenylalanine(S-Phe)with divalent calcium(Ca^(2+))complex(Phe·Ca^(2+))in aqueous solution was studied by using M06-2X and MN15 methods based on DFT(density functional theory)and SMD model method to deal with solvent effect.The study of reaction channel found that enantiomerism of S-Phe·Ca^(2+)can be realized on three channels in which protons use N as bridge,O as bridge,O and N combine to form a bridge.The calculation shows that the reaction channel of H proton transfer with amino N as bridge has advantages under the effect of recessive solvent and its energy barrier is 227.5 kJ/mol,and the barrier is reduced to between 108.0 and 117.6 kJ/mol under the dominant solvent effect.According to the research results,chiral Phe·Ca^(2+)complex is hard to racemize in aqueous solution,and it might be safer to be used for life supplementing phenylalanine and calcium.

关 键 词：苯丙氨酸 二价钙 DFT(density functional theory) 对映异构 自由能垒 

分 类 号：O641.12[理学—物理化学]