Síntese e caracterização de análogos de chalconas bromadas para a avaliação de atividades biológicas

Abstract

Chalcones, a subgroup of naturally occurring flavonoids, exhibit various pharmacological properties reported in the literature. Given the structural diversity of chalcones, evaluating structure-activity relationships represents a promising strategy to enhance their biological activities. In this context, halogenated chalcones have attracted growing interest due to their efficacy against bacteria, fungi and protozoa. Therefore, the aim of the present study is to synthesize, via Claisen-Schmidt condensation, characterize, and evaluate the biological activities of a series of brominated chalcones. Twenty-two brominated chalcones were synthesized with yields ranging from 26% to 91%, characterized by Fourier-transform infrared spectroscopy, high-resolution mass spectrometry, and proton and carbon nuclear magnetic resonance. High-resolution mass spectrometry confirmed the molecular formulas of the products. Infrared absorption and nuclear magnetic resonance spectroscopic analyses confirmed the synthesized products. Structure-activity analysis revealed a potential correlation between the molecular structures of the chalcones and their bacterial growth inhibition values for Acidovorax citrulli, with results up to 54,94%, while antifungal assays for Sclerotium sp., Macrophomina phaseolina, and Lasiodiplodia sp. showed the best results ranging from 20% to 30%. Additionally, promising antiprotozoal activity results were observed for Leishmania amazonensis promastigotes, with inhibition up to 99.81%. Finally, this study provides a foundation for constructing a diverse structural library for future investigations aimed at developing more effective therapies, thereby contributing to advances in the fields of medicinal chemistry and microbiology.