Síntese, caracterização, estudo teórico e atividade biológica de chalconas hidroxiladas.

Abstract

This paper presents the synthesis of five chalcones: CHAL, 2-CHALOH, 4-CHALOH, 2'-CHALOH and 2',2-CHALOH through Claisen-Schmidt's aldolic condensation methodology, in addition to performing spectroscopic characterizations, by NMR and FT-IR techniques, theoretical calculations of conformational analysis, evaluation of biological activity and use of these synthesized chalconas to obtain metal complexes with several metal centers. Through spectroscopic characterizations it is possible to observe the efficiency in obtaining the chalcones, with the presence of characteristic bands for these compounds in FT-IR and the presence of signs that prove the formation of chalcones, mainly the signal referring to the formation of the double C=C, with coupling constant 3JHH between 14 and 18 Hz. Regarding the theoretical calculations of the conformational equilibrium, one can observe the preference in configuration (E), and the highest percentage of population in equilibrium being in scis conformations, as well as the analysis of orbital interactions that most contribute to the stability of structures. Regarding the evaluations of biological activities, the potential of hydroxylated chalconas as good antioxidants, with 4-CHALOH presenting a 60.79% DPPH radical inhibition result, and a promising antimicrobial activity, with good results found against strains of E. Coli and S. aureus. In order to obtain metal complexes using chalcones as ligands, it is possible to observe the success in the synthesis of the cobalt complex with 4-CHALOH and the nickel complex with the 2’- CHALOH. However, future studies are needed to improve synthetic conditions as well as further analysis of the characterization of metal complexes, for better characterization of them.