Síntese, caracterização e estudo da atividade biológica de aminochalconas: uma abordagem estatística da relação estrutura-atividade

Abstract

Chalcones are key intermediates in the biosynthesis of flavonoids, characterized by a structure consisting of two aromatic rings linked by a propenone moiety, forming an α,β-unsaturated system. These compounds have garnered considerable attention due to their structural versatility and a wide range of reported biological properties, including antifungal, antibacterial, and antioxidant activities. In the present study, seven chalcone derivatives were synthesized via the Claisen–Schmidt aldol condensation under basic conditions. Structural characterization was performed through one- and two-dimensional Nuclear Magnetic Resonance (NMR) spectroscopy, along with the determination of melting points. Spectroscopic data confirmed chalcone formation, as indicated by the presence of characteristic signals of the α,β-unsaturated ketone and the absence of resonances corresponding to the starting materials. The melting points obtained were consistent with literature values, further supporting compound identity. In antioxidant assays, derivative CHAL 2B exhibited superior efficiency in donating hydrogen atoms or electrons for radical stabilization. Regarding antimicrobial evaluation against Staphylococcus aureus and Escherichia coli, the compounds demonstrated moderate inhibition of bacterial growth. In biofilm formation assays, a more pronounced antibiofilm effect was observed against S. aureus, whereas the effect against E. coli was comparatively lower. For antifungal activity against Candida albicans, all derivatives significantly inhibited fungal growth. In summary, all target compounds were successfully synthesized and thoroughly characterized. The chalcones assessed displayed noteworthy biological potential, particularly in antioxidant and antifungal activities, underscoring their relevance for future pharmacological applications and structure–activity relationship investigations.