Acta Scientiarum Naturalium Universitatis Sunyatseni

   

Chiral transition mechanism of Mg2+and Ala complexes and effect of ater molecules (clusters) and water solvents

ZHANG Xuejiao1,2, LIU Fang2,3, WU Zihao4, XÜ Ruiying1,2, MA Hongyuan2,3,YANG Xiaocui2,3, WANG Zuocheng2,3   

  1. 1. Theoretical Computing Center, Baicheng Normal University, Baicheng 137000, China;
    2. Communication College, Baicheng Normal University, Baicheng 137000, China;
    3. College of Physics, Baicheng Normal University, Baicheng 137000, China;
    4. School of Environment, Universitatis Sun Yat-sen University, Guangzhou 510257, China
  • Received:2020-02-21 Online:2020-07-08 Published:2020-07-08

Abstract:

The title response was studied using the M06 method based on density functional theory and SMD model method combined with self-consistent reaction field theory. The study showed that the zwitterionic chelate S-A_1 formed by alanine (Ala_1) and Mg2+ di-coordination with intramolecular single hydrogen bond is the most stable. The neutral ion chelate S-A_2 formed by the double coordination of Ala_2 and Mg2+ with intramolecular double hydrogen bond is the second stable. The chiral transition of both S-A_1 and S-A_2 has three pathways. Potential energy surface studies showed that the chiral transition dominant pathways activation energies of S-A_1 and S-A_2 are 297.5 kJ·mol-1 and 266.5 kJ·mol-1 respectively in gas phase, and are 157.9 kJ·mol-1 and 165.7 kJ·mol-1 respectively with the effect of water molecules (clusters). Alanine and Mg2+ chelates exist mainly in the form of zwitterions in water solvent environment, and the chiral transition dominant pathways activation energies are 157.5 kJ·mol-1. The results showed that the alanine and Mg2+ chelate can maintain its chiral characteristics well and is easy to be preserved. It can be used as an ideal medicine or nutrition supplement for alanine and magnesium ions.

Key words:

α-alanine(α-Ala), magnesium ion (Mg2+), chiral transition, density functional theory, transition state, self-consistent reaction field theory; energy barrier

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