Caracterização vibracional, termodinâmica e optoeletrônica de inibidores de acetilcolinesterase.

Abstract

In this work we present a study for a optoeletronic, vibrational and thermodynamic properties of Acetylcholinesterase Inhibitors, conducted through quantum calculations by Density Functional Theory, using the Local Density Approximation - LDA and Generalized Gradient Approximation - GGA. These molecules have the capacity to inhibit the action of the enzyme acetylcholinesterase, which acts directly on synaptic transmission in the central nervous system. One credits to these inhibitors the ability to contribute to improved levels of acetylcholine in the human body, on the other hand acetylcholine is a neurotransmitter and its presence in the organism is essential to maintenance and development human cognitive; it is believed that the absence of this neurotransmitter leads to dementia state, causing the known Alzheimer's disease. The selected drugs for this study were Tacrine, Donepezil, Rivastigmine, Galantamine and Physostigmine. For the implementation of the calculation we used the computer simulation software Conformers applied for the conformational calculations and for the other properties the DMol³. The properties were obtained for the lowest energy molecular structure for each molecule, It is possible to carry out study on the molecular orbitals HOMO and LUMO, density of state (PDOS), Besides the optical absorption spectra, infrared (IR) and Raman scattering. The calculated thermodynamic properties were entropy, enthalpy, free energy and the thermal capacity. All calculations were performed using functional LDA/PWC and GGA/PBE.