DFT and Ab initio computational study on the reactivity sites of the GABA and its agonists, such as CACA, TACA, DABA, and muscimol: In the gas phase and dielectric media

Abstract

The reactive behavior of GABA and its agonist molecules have been investigated using B3LYP hybrid density functional method at the 6-311þþG** basis set level, in the gas phase and dielectric media. The calculations have been performed to obtain optimized geometries, relative energies, net atomic charges, HOMO, and LUMO energies. Solvent effects have been analyzed using isodensity polarized continuum model (IPCM) for four different solvents, which are chloroform, ethanol, DMSO, and H 2 O. The results have suggested that both the amino group and carboxyl group have been two of the most important active site for interactions between all compounds and their receptors. In addition they have suggested that the amino group reflects the difference in biological activity for each all molecules. The structures of these agonists have provided an essential foundation for subsequent structure-activity analysis of ligand binding at GABA receptors, neuronal uptake inhibitors and transporters.

Thiol modifier effects of diphenyl diselenides: insight from experiment and DFT calculations

“…Taking into account the thermal contributions, the Gibbs free energies of the reaction in solution are less negative than those in the gas phase, since the presence of the solvent electrostatic field stabilizes the charged species found in the reactants and products with a stronger effect on the reacting thiolate than on the produced selenolate, thus mitigating the energy difference of the two anions. 71,72 The reaction with R = CF 3 presents the largest negative energy, being around twice the one computed for R = CH 3 O (ΔΔ G = 4.62 kcal mol −1 , Table 3) confirming the beneficial effect of the electron withdrawing groups in yielding more favourable thermodynamics.…”

Electrochemical investigations and theoretical studies of biocompatible niacin-modified carbon paste electrode interface for electrochemical sensing of folic acid

“…Thermodynamic quantities provide very useful information on a specific reaction and/or interaction process between the reactant(s) and product(s) and are generally determined experimentally. On the other hand, these quantities are also successfully predicted theoretically (Serdaroğlu 2011) depending on the development of both the computer and technological sciences. The optimized geometries and physical quantities of two niacin conformers are displayed in Table 1 and Fig.…”

New Hybrid (E)‐4‐((pyren‐1‐ylmethylene)amino)‐N‐(thiazol‐2‐yl)benzenesulfonamide as a Potential Drug Candidate: Spectroscopy, TD‐DFT, NBO, FMO, and MEP Studies**

“…In applied and/or theoretical sciences, the physicochemical and thermodynamic quantities have an essential role in the evaluation of the relevant chemical process and their stability. [66][67][68] In this respect, the calculated quantities and their dependence on the solvent media were given in Table 1. The optimized structure of compound 3 with atom-labeling and -numbering was displayed in Figure 2.…”

“…FMO energy analyses and visuals of them are frequently used for many different fields and molecular systems, from elucidating the electronic structures of basic molecules [66][67][68]72] to determine the activities of complex or very large molecular systems. [78,85,[89][90][91] In this regard, the calculated reactivity parameters were obtained from the three solvent media simulations to look for the relationship between the simulation media and reactivity behavior and were displayed in Table 7.…”