Banca de DEFESA: WILLIAM QUEIROZ FELIPPE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : WILLIAM QUEIROZ FELIPPE
DATE: 03/08/2023
TIME: 14:00
LOCAL: Virtual
TITLE:

Synthesis and evaluation of the antifungal action of chalcones and their derivatives
phenethyl-imino-chalcones and thiosemicarbazone chalcones

KEY WORDS:

Chalcones, phenethyl-imino-chalcones, chalcones-thiosemicarbazones, antifungal

PAGES: 115
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Orgânica
SPECIALTY: Síntese Orgânica
SUMMARY:

Research in the field of Mycology indicates an alarming increase in the frequency of opportunistic fungal infections and among them, the actions of yeasts and filamentous fungi that cause various problems for the agrarian, food and pharmacological sectors are observed. Chalcones are composed of relevant applications for organic synthesis, since they are substrates that allow a wide variety of structural modifications, producing new structures with the most diverse biological properties. Of the eight precursor chalcones synthesized for this work, four were selected due to previous evaluation against the species Aspergillus parasiticus and A. carbonarius, to proceed with the synthesis of the compounds of the phenethyl-imino-chalconas (FIC) classes and chalcone-thiosemicarbazones (CT). The FIC class was obtained from the respective chalcones and 2-phenethylamine in ethanol under microwave irradiation and the CT class was obtained through chalcones and thiosemicarbazide in ethanol under reflux. Both classes were evaluated for their antifungal capabilities against different species of fungi of the genera Aspergillus, Candida and Sporothrix, and were evaluated for their ability to chelate Fe²⁺, important biological factor for several fungi. The results of radial growth inhibition assays against strains of A. carbonarius and A. parasiticus showed significant improvements in fungal proliferation retardation activities of both classes of derivatives compared to precursor chalcones. MICs (minimum inhibitory concentration) of chalconic derivatives were evaluated against different fungal strains, presenting greater inhibitory capacity against C. albicans for FIC-Cl (3,90 μg mL^-1 ), C. krusei for CT-H, CT-F, CT-Cl and CT-Br (3,90 μg mL^-1 , 7,80 μg mL^-1 , 7,80 μg mL^-1 and 3,90 μg mL-1 , respectively), C. tropicalis for FIC-Cl (125 μg mL^-1 ), S. schenckii for FIC-H, FIC-F, CT-H (500 μg mL^-1 , 250 μg mL^-1 and 500 μg mL^-1 , respectively), S. brasiliensis for FIC-F (250 μg mL^-1 ) FIC-H, FIC-Cl, CT-H, CT-F, CT-Cl and CT-Br (500 μg mL^-1 ) and Sporothrix spp. (clinical strain) for derivatives FIC-H, FIC-F, CT-H, CT-F, CT-Cl and CT-Br (500 μg mL^-1 , 500 μg mL^-1 , 500 μg mL^-1 , 250 μg mL^-1 , 125 μg mL^-1 , 500 μg mL^-1 , respectively). The evaluation of chelating activity indicated the greatest effects for the most active derivatives against Candida species (CT-Br, CT-Cl and FIC-Cl) suggesting complexation with Fe²⁺ ions. In general, the CT derivatives presented higher antiproliferative effects and, thus, with the results of this work it is expected to contribute to the development of new antifungal agents for the control of mycotoxigenic fungi.

COMMITTEE MEMBERS:
Presidente - 387189 - AUREA ECHEVARRIA AZNAR NEVES LIMA
Externa ao Programa - 2451384 - ANDRESSA ESTEVES DE SOUZA DOS SANTOS - UFRRJExterna à Instituição - JACQUELINE SANTOS CRUZ - IME