Congresso Brasileiro de Microbiologia 2023

Congresso Brasileiro de Microbiologia 2023

Resumo: 37-1

37-1

CATECHOLIC CHALCONES AS PROMISING AGROCHEMICAL MOLECULES AGAINST Xanthomonas spp.

Autores:

Daniela Silva Gonçalves (UFU - Universidade Federal de Uberlândia ) ; Nagela Bernadelli Sousa Silva (UFU - Universidade Federal de Uberlândia ) ; Nilvanira Donizete Tebaldi (UFU - Universidade Federal de Uberlândia ) ; Paulo de Tarso da Costa (UNESP - Universidade Estadual Paulista) ; Luis Octávio Regasini (UNESP - Universidade Estadual Paulista) ; Carlos Henrique Gomes Martins (UFU - Universidade Federal de Uberlândia )

Resumo:

Xanthomonas is a genus of Gram-negative bacteria that affects a wide range of plants worldwide, including citrus, cruciferous, tomato, corn, onion, for example, and, consequently, of great economic importance. Due to the development of antibacterial resistance, streptomycin and copper-based pesticides reduce symptoms, but do not eliminate the infection. Chalcones, precursors in the biosynthesis of flavonoids, are currently considered as promising molecules for the synthesis of new drugs through the manipulation of its aromatic rings. This study aimed to evaluate the antibacterial activity and toxicity of 14 catecholic chalcones, where ring B possesses two meta and para positioned hydroxyl groups, and modifications were performed on ring A: MM17 (1); RL-2’CH3 (2); RL-3’OH (3); RL-4’OH (4); MM14H (5); MM20-2’furan (6); RL-3’OCH3 (7); MM74’OCH3 (8); MM10-4-CH3 (9); MR2-2’Naft (10); RL-3,4Cl (11); 4F-RL (12); RL-4’Br (13) and VSO1-4etil (14) against Xanthomonas spp. The isolated phytopathogens X. campestris pv. campestris; X. vasicola pv. vasculorum; X. euvesicatoria pv. perforans; X. citri (resistant to copper - RC); X. citri (tolerant to copper - TC); X. citri (sensible to copper - SC) were used in the assays of Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and in vivo toxicity of the greatest samples was evaluated in Caenorhabditis elegans model. MIC results varied between >400 and 12.5 µg/mL. The values were promising for: 1 against X. citri (RC), X. citri (TC) at a concentration of 12.5 µg/mL and X. e. pv. perforans at a concentration of 25 µg/mL; 2 against X. e. pv. perforans, X. citri (TC) at 25 µg/mL and X. c. pv. campestris, X. v. pv. vasculorum, X. citri (RC) at 50 µg/mL; 3 against X. c. pv. campestris, X. v. pv. vasculorum, X. citri (TC) at 25 µg/mL and X. e. pv. perforans, X. citri (RC) at 50 µg/mL; 4 against X. v. pv. vasculorum, X. citri (RC) and X. citri (TC) at 50 µg/mL. MBC values were the same as MIC values for all samples and bacteria, that is, the samples presented bactericidal activity. In toxicity assay, the lethal concentration (LC50) of: 1 was found at 31,25 µg/mL in 72 hours of exposure; 2 and 4 at 125 µg/mL in 72 hours; 3 at 250 µg/mL in 48 hours, all results presented toxicity at concentrations higher than concentrations that have antibacterial properties. It is concluded that catecholic chalcones demonstrated antibacterial activity against most of the studied Xanthomonas spp. and they are not toxic in the model and concentrations evaluated.

Palavras-chave:

Antibacterial activity, Chalcones, Toxicity, Xanthomonas

Agęncia de fomento:

CAPES, CNPq