INTERACTION OF QUERCETIN WITH SEROTONIN. THERMODYNAMIC EVALUATION

10.25712/ASTU.1811-1416.2024.04.010

Abstract

Quercetin is a natural flavonoid and antioxidant. Serotonin is one of the neurotransmitters of the human nervous system, known as the "hormone of happiness". Serotonin is toxic when administered intravenously. The possibilities of binding serotonin to adipic acid are known to eliminate the problem of toxicity. From this point of view, it may be useful to introduce a complex of serotonin with quercetin into the body, where the complex could safely break down into components. In the future, each of the components could exhibit its target properties. It is necessary to assess the possibility of the formation of complexes of these substances that differ in composition and structure. Quantum chemical modeling of possible combinations in the quercetin-serotonin system was carried out in the Gaussian 09, B3LYP/6-31+G** program, the «gas» model (excluding the environment) and the aquatic environment. For each of the variants, the Gibbs energies (G) of both reagents, possible reaction products, and a change ∆G in the named transformation routes were found. The results obtained show that the minimum change in the Gibbs energy of the reaction is observed when quercetin interacts with serotonin according to the type of ammonium salt formation. A promising option may be the interaction of quercetin at the 5 position of the active hydroxyl groups with the amine nitrogen of serotonin. In this case, a direct reaction in the so called «gas» is possible, the reverse reaction becomes possible when the medium changes to an aqueous one. This situation can be realized by conducting a direct reaction in mechanochemical synthesis followed by the transfer of the quercetin-serotonin complex into an aqueous medium, for example, into the body. Then, it turns out to be thermodynamically advantageous to hydrolyze the complex into the initial target components.