Chalcone-Derived Lactones: Synthesis, Whole-Cell Biotransformation, and Evaluation of Their Antibacterial and Antifungal Activity

Four compounds with lactone moiety were synthesized from chalcone in three- or four-step synthesis. γ-Bromo-δ-lactone was the only product of bromolactonization of acid whereas bromolactonization of ester , apart from lactone also afforded its isomer and two diastereoisomeric δ-hydroxy-γ-lactones and . Lactone was also obtained in 88% yield as a product of simultaneous dehalogenation and translactonization of γ-bromo-δ-lactone by AM 359. Chalcone-derived lactones - were subjected to the tests on antimicrobial activity and the results compared with activity of starting chalcone . Obtained lactones - in most cases limited the growth of tested bacterial and fungal strains. The highest activity was found for δ-hydroxy-γ-lactone which completely inhibited the growth of , , and sp. The introduction of lactone moiety into chalcone scaffold significantly improved antimicrobial activity of the compound: γ-bromo-δ-lactone and δ-hydroxy-γ-lactone were significantly stronger growth inhibitors of and . In the case of the latter, a clear positive effect of the lactone function on the antifungal activity was also observed for γ-bromo-δ-lactone .