Theoretical study about L-arginine complexes formation with thiotriazolin

• Published in: Zaporozhye Medical Journal
• Main Authors: L. I. Kucherenko, O. V. Hromyleva, I. A. Mazur, S. V. Shishkina
• Format: Article in Journal/Newspaper
• Language: English; Russian; Ukrainian
• Published: Zaporozhye State Medical University 2017
• Subjects: L-arginine; thiotriazolin; quantum-chemical calculations; molecular complexes; Medicine; R; Vina; Orca
• Online Access: https://doi.org/10.14739/2310-1210.2017.1.91736; https://doaj.org/article/668a1cfe008d4104ba719f50fe4fa7c0

Brain vascular diseases are one of the leading causes of morbidity, mortality and disability of population in the industrialized countries of the world. An important element of this problem’s solution is the creation of new highly effective and safe drugs, which would lead to mortality reduction, to increase in life expectancy and quality of life. Therefore it is interesting to create a new combined drug based on L-arginine and thiotriazolin. Purpose of the study: to consider the possible structure and energy characteristics of complexes formed by L-arginine, 3-methyl-1,2,4-triazolyl-5-thioacetate (MTTA) and morpholine. Calculation method. The initial approximation to the complex geometry was obtained using molecular docking with the help of AutoDock Vina program. The obtained ternary complexes were pre-optimized by semi-empirical PM7 method with modeling the impact of the environment by COSMO method. The calculations were carried out using MOPAC2012 program. Then they were optimized by B97-D3/SVP + COSMO (Water) dispersion-corrected DFT-D with geometrical spreading correction on insufficiency of gCP basis set. A more accurate calculation of the solvation energy was conducted by SMD. The calculations by density functional method were carried out using the ORCA 3.0.3 software. Energy complex formation in solution was calculated as the difference of the Gibbs free energy of the solvated complex and its individual components. Results. Quantum chemical calculations show, that thiotriazolin and L-arginine are able to form ternary complexes, where molecules are linked by multiple hydrogen bonds. The calculation data suggest, that studied complexes are thermodynamically unstable in solution. The energies of them are positive, but rather low despite charge gain of a number of intermolecular hydrogen bonds. Finding. Based on the results of the conducted quantum-chemical study of a three components system (MTTA, morpholine, and L-arginine) it is possible to show the possibility to form ternary complexes with low stability ...