Antifungal effects of thiosemicarbazone-chalcones on Aspergillus, Candida and Sporothrix strains

The frequency of opportunistic fungal infections has been increasing, impacting agriculture, food, and health sectors. In this work, four thiosemicarbazone-chalcones (TC) were synthesized and evaluated by the radial diffusion method against filamentous fungi. All TCs were effective against Aspergillus parasiticus, especially the fluor-substituted one, with radial growth inhibition of 62,9% and 74,4% at the lower (0.209 µmol/ml) and highest (1.670 µmol/ml) concentrations tested, respectively. On the other hand, the non-substituted derivative was the most active against A. carbonarius, inhibiting radial growth by 47,9% and 74,1% at 0.222 µmol/ml and 1.777 µmol/ml, respectively. Additionally, the compounds were evaluated against the dimorphic fungi Sporothrix brasiliensis, S. schenckii, and a clinical strain of Sporothrix spp, exhibiting minimum inhibitory concentrations (MICs) in the range of 0.396–1.777 µmol/ml. When tested against four yeasts of the Candida genus, the thiosemicarbazone-chalcones demonstrated greater activity against C. krusei (MICs 0.011–0.026 µmol/ml).