Conference publications


XXIX conference

Molecular modeling and analysis of the conformers structures in order to research succinic acid conformational polymorphism

Zakharov A.A., Plastun I.L.

Yuri Gagarin State Technical University of Saratov, 77 Politechnicheskaya street, Saratov, 410054

1 pp. (accepted)

The aim of this work is to researching the conformational polymorphism of succinic acid by analyzing the structures of conformers obtained by quantum chemical molecular modeling based on the density functional theory.

Low solubility and bioavailability of drugs are among the significant problems of modern pharmacology. One of the ways to solve this problem is to obtain new polymorphic forms of drugs with improved physicochemical properties. The features of the created polymorphic modifications are an increase in the dissolution rate, the possibility of reducing the dosage, and a decrease in toxic or side effects [1].

Polymorphism is the ability of a substance to exist in various crystalline forms, while having the same chemical composition. Such forms are called polymorphic modifications [2].

Succinic acid or butanedioic acid is a dicarboxylic acid consisting of four carbon atoms and found in plant and animal tissues.

Succinic acid has many uses in the pharmaceutical industry - for example, it is a starting material for active pharmaceutical ingredients (API), as a formulation additive, succinic acid monoethyl ester has been used as an insulinotropic agent, and the compound is also used as a crosslinking agent in polymers that control medicine. In medicine, succinic acid is often included in some medicines.

In the course of calculations, the structures and IR spectra of various variants of succinic acid were calculated. By analyzing the differences in the energies of the conformers, the optimal variants of the structures of succinic acid were found, both for a single molecule and for a dimer of succinic acid.

Molecular modeling procedures were carried out using the Gaussian 09 software package. The B3LYP functional and the 6-31G basis set were used for calculations.

In the course of the research, various variants of the structures of succinic acid were considered, as a result of which, by analyzing the energy difference, variants of conformers were found, both for one molecule and for the dimer of succinic acid. Of all the considered variants of the conformers of a single succinic acid molecule, 3 variants turned out to be optimal. For the dimer of succinic acid, 4 variants of conformers were found to be optimal. The results obtained can be used to create polymorphic modifications of succinic acid.


1. Zhou Y., Wang J., Xiao Y., Wang T., Huang, X. The effects of polymorphism on physicochemicalproperties and pharmacodynamics of solid drugs // Current Pharmaceutical Design. 2018. V.24(21). P. 2375-2382.

2. Gentili D., Gazzano M., Melucci M., Jones D., Cavallini M. Polymorphism as an additional functionality of materialsfor technological applications at surfaces and interfaces // Chemical Society Reviews. 2019. V.48(9). P. 2502-2517.


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