Investigação das propriedades vibracionais, estruturais e eletrônicas através de cálculos DFT e estudos de docking molecular de alcaloides isolados de plantas da flora amazônica: uma abordagem teórica para moléculas bioativas

Abstract

The alkaloids constitute a class of metabolites with great biological activity and o great importance in human history. Among the several classes, the idole and oxoaporphine type alkaloids are worth mentioning. About 1000 of these types alkaloids have already been isolated from plants, however theoretical studies that justify their activities providing new data about their structural, spectroscopic and quantum properties lack in the literature. Based on this premise, the present study investigated the alkaloids strictosidine, stricnobrasiline, 12-hydroxy-10,11-dimethoxystricnobrasiline, liriodenine, cantinone and 7-methoxy-cantinone through a theoretical approach by DFT calculations using the hybrid electronic correlation function B3LYP and the 6-31 G (d), 6-311G (2d, p) and 6-311G ++ (2d, p) basis set. Theoretical geometric optimization data were compared with X-ray spectroscopy data of similar structures in the literature presenting similar values. In addition calculations of Natural Bond Orbitals (NBOs), HOMO and LUMO orbitals and electrostatic potential maps were performed. Theoretical spectra of UV-Vis revealed to be quite similar to the experimental spectra being possible to signal the electronic transitions. Based on the maps of electrostatic potential and the theoretical spectra of IV (by stretches N-H and O-H) it was possible to predict the formation of hydrogen bonds that influences de physic-chemical properties. Molecular docking calculations against human DNA-Topoisomerase II enzyme complexes and Candida albicans dihydropholate reductase were carried out in order to perform the described activities in literature.