Novel esters derived from 4-hydroxychalcones as potential sunscreens with antimicrobial action

Ten novel 4-esterchalcones, licochalcone analogues, were strategically synthesized to study the effect of electro-donating or electro-withdrawing substituents in the aryl enone moiety on their pharmacological and photoprotective properties. 4-Esterchalcones had their drug-like character evaluated, which demonstrated positive characteristics for the development of novel drug candidates. In the in vitro antimicrobial evaluation, isovaleryl 4-esterchalcones showed activity against strains of Staphylococcus aureus, Candida albicans and C. tropicalis with minimum inhibitory concentration (MIC) in the range of 2.64-3.32 µmol mL⁻¹, and the isobutyryl 4-esterchalcone 5d (4’-Br) presented antimicrobial activity against all strains tested, with a MIC of 2.74 µmol mL⁻¹. In the UV-Vis study, λ_max were observed at 312-327 nm, the UVB range, mainly. The best SPF-UVB results ranged from 18.04 to 21.06, with high ε_max values, indicating that 4-esterchalcones have the potential to act as sunscreens. Furthermore, along with the environmental concern, halogenated compounds demonstrated slightly toxic on Artemia salina.