Atividade antimicrobiana de derivados de chalcona sobre fitopatógenos do gênero Xanthomonas ssp

Abstract

Chalcone is a molecule that is considered a source for developing of less toxic, low cost and efficient chemical pesticides against various types of disease because it has easy manipulation and various biological activities already related. The present study aimed to evaluate the antimicrobial activity of chalcone and its derivatives on five phytopathogenic species of the genus Xanthomonas. Antibacterial and antibiofilm activity was evaluated, and the effect of the chalcone derivative on the cell membrane was evaluated using Propidium Iodide. Among the 16 derivatives tested, C6 ((E)-1-phenyl-3-α naphthylprop-2-en-1-one) showed 100% growth inhibition of Xanthomonas campestris pv. campestris (Xcc) at a 2000µg/mL concentration, the minimum inhibitory concentration (MIC). Inhibition of biofilm formation was below 40% for all tested molecules. It was also possible to observe the increase in Propidium Iodide (PI) fluorescence, directly proportional to the exposure time and concentration of the treatment with C6 derivative, with about 100% of the cells with the damaged cell membrane at the concentration of 2xMIC (4000µg/mL) in 24 hours of incubation. In conclusion, among the 16 chalcone derivatives tested, the C6 chalcone derivative showed better antimicrobial activity for three of the five species tested, while the C16 derivative showed better antimicrobial activity for the other two. The C6 derivative showed 100% growth-inhibiting of Xcc at a concentration of 2000µg/mL.