Efeito estrutural do substituinte metoxi no derivado Quinolínico C28H19ClN2O5S

Abstract

Natural or synthetic compounds are widely used as a starting point for new bioactive molecules. This phenomenon is known as guided synthesis and has the objective of coupling to active biological site. Hybrid compounds between chalcones and quinolines, due to their multifaceted biological activity, have become starting material for specific modifications, through molecular modeling, seeking to maintain the active site of the molecule, as they have great chances of potentiating biological effects, reducing adverse effects, improving solubility or circumvent microbial resistance. However, only with the structural elucidation we can obtain a deep knowledge of the structure and its physical behavior, it can also be compared with already published structures and evaluate the obtained impacts. In this merit, a quinoline derivative had its composition elucidated by x-ray diffraction and geometric parameters, intermolecular interactions and supramolecular arrangement were evaluated, in addition to theoretical calculations of density and electrostatic potential map, in comparison with data from a similar bioactive structure, already published, whose difference lies in a methoxy substituent in place of chlorine. The comparative data obtained reveal significant differences in the pattern of electrostatic interactions. Stabilized by C-H···O interactions, these differ in position and make room for the structure with methoxy to present a π···π as opposed to C-H···π found in the chlorinated compound, in this same context, the Hirshfeld surfaces were calculated, which revealed the types and values, in addition to graphically expressing the hydrophobic interactions for both structures. Complementary evaluations such as the size of the covalent bonds, the bond angles, as well as the angles between the planes of the rings, were analyzed and it was found that there were differences in all geometric aspects. To deepen the analysis, theoretical calculations were performed, based on the Density Functional Theory (DFT), which showed a lower, but timid, chemical stability and higher reactivity for the methoxylated quinoline derivative. Finally, an electrostatic potential map analysis revealed differences in electron density evidencing changes in binding sites between the compounds.