Banca de DEFESA: ALÉCIA REGINA ANDRESA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ALÉCIA REGINA ANDRESA SILVA
DATE: 31/07/2024
TIME: 18:00
LOCAL: Departamento de Química
TITLE:

DEVELOPMENT OF NEW AMIDOXIMIC PROTOTYPES APPLIED IN THE FIGHT Aedes aegypti

KEY WORDS:

Amidoximes; Aedes aegypti; Larvicidal; Synthesis

PAGES: 106
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Orgânica
SPECIALTY: Síntese Orgânica
SUMMARY:

The increasing emergence and spread of arboviruses, such as those responsible for diseases such as dengue, Zika, chikungunya and yellow fever, have been accelerated by the ability of vectors, mainly the Aedes aegypti mosquito, to sustain transmission between humans. This ability is amplified by the adaptation of arthropods to urbanization, which eliminates the need for their forest cycles and natural reservoirs. Given the absence of a single and effective strategy to control these vectors, organic chemistry plays a crucial role in the synthesis and isolation of new molecules that can act as control agents. In this study, the objective was to synthesize and characterize different O-alkylated amidoximes and evaluate their larvicidal potential against Aedes aegypti. The synthesis of amidoximes was carried out by the reaction between hydroxylamine hydrochloride and benzonitrile, using a hydroethanolic medium and sodium bicarbonate, with mechanical stirring at room temperature (25±2 ºC). The optimization of the reaction conditions for the O-alkylation of amidoximes involved the analysis of different parameters, such as temperature, energy input and basic species. The most efficient condition, which resulted in the best yields, was the use of mechanical energy (45±5 °C) with KOH as the basic species and DMSO as the solvent. After synthesis, the amidoximes were purified by crystallization in chloroform and hexane, while the O-alkylamidoximes were purified by glass column chromatography. The purification yields ranged from 43% to 87%. Subsequently, they were characterized by Infrared (IR) and Hydrogen and Carbon Nuclear Magnetic Resonance (¹H and ¹³C NMR) spectroscopic methods. In the next step, larvicidal tests were performed to evaluate the efficacy of the new molecules against Aedes aegypti larvae. Of the ten amidoxime derivatives tested, two stood out with promising larvicidal activity. 4-Bromo-O-(2,2-diethoxyethyl)benzamidoxime showed an LC₅₀ value of 247.58 ± 5.09 ppm, while 4-O-(2,2-diethoxyethyl)pyridinamidoxime obtained an LC₅₀ value of 198.44 ± 11.52 ppm. These results indicate that these compounds have significant potential for the control of Aedes aegypti and, consequently, for the mitigation of diseases transmitted by this vector.

COMMITTEE MEMBERS:
Presidente - ***.451.424-** - JULIANO CARLO RUFINO DE FREITAS - UFCG
Interno - JOAO RUFINO DE FREITAS FILHO
Externa à Instituição - JOSEFA AQUELINE DA CUNHA LIMA - UFRA