水溶液环境下赖氨酸钠配合物手性转变的理论研究

The Theoretical Study on the Chiral Flip of Lysine Na+Complex in Aqueous Solution

该文采用密度泛函理论(DFT)的M06-2X方法和MN15方法,结合处理溶剂效应的SMD模型方法,研究在水溶液环境下赖氨酸钠配合物(Lys·Na^(+))的手性转变.研究结果发现:Lys·Na^(+)的手性转变反应可在3个通道上实现,它们分别是α-H以羰基O为桥迁移、α-H迁移到羰基O后氨基N上的H再向α-C迁移以及α-H以氨基N为桥迁移.计算结果表明:α-H以氨基N为桥迁移的反应通道最具优势,在隐性水溶剂效应下该通道的自由能垒为221.6 kJ·mol^(-1),水簇的作用使该能垒降为115.6~119.0 kJ·mol^(-1).研究结果表明:Lys·Na^(+)在水溶液环境下的手性转变很缓慢,其用于生命体同补赖氨酸和钠离子比较安全.

The chiral flip of Lysine Na+complex(Lys·Na^(+))in aqueous solution is 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 finds that chiral flip reaction of Lys·Na^(+)can be achieved in three channels thatα-H uses carbonyl O atom as bridge,amino group H transfers toα-C after the α-H transferring to carbonyl O atom andα-H uses amino group N as bridge.The calculation shows that the reaction channel of α-H transfers with amino group N as bridge has the most advantage,its free energy barrier is 221.6 kJ·mol^(-1) under the effect of recessive solvent,and the barrier can be reduced to between 115.6 and 119.0 kJ·mol^(-1) under the effect of water clusters.According to the research results,the chiral flipping process of Lys·Na^(+)is very slow in aqueous solution,and it is relatively safe to be used to supply Lys and Na+for life simultaneously.