Determination of diflubenzuron residues in milk and cattle tissues / Determinação de resíduos de diflubenzuron em leite e tecidos bovinos

Diflubenzuron (DFB) is used to control ectoparasitic infestation by inhibiting larvae development in the manure and feces of treated animals. It is also currently been used to control tick infestations. In this study, milk and tissues from cattle treated orally with DFB for a 77-120 day period with a commercial product containing the compound were analyzed for the presence of residues. DFB residues were determined by using extraction with acetonitrile, cleanup with C18 SPE and chromatographic analysis by HPLC with UV detection (254nm). DFB was not detected in any of the analysed samples (<0.006mg kg-1 for fat, <0.014mg kg-1 for muscle, <0.015mg kg-1 for kidney, <0.016mg kg-1 for liver and <0.0006mg kg-1 for milk). In this manner, the use of this compound, according to the manufacturer's suggested doses may result in cattle milk, liver, kidneys, fat and muscles being considered safe regarding the presence of DFB residues.

O diflubenzuron (DFB) é um inibidor de desenvolvimento de insetos que inibe a síntese de quitina com atividade ovicida e larvicida e está sendo utilizado na pecuária para o controle do carrapato. Leite e tecidos provenientes de bovinos tratados por um período de 77 a 120 dias com um produto comercial contendo DFB foram analisados quanto à presença de resíduos. Os resíduos de DFB foram determinados utilizando-se extração com acetonitrila, limpeza por SPE C18 e cromatografia líquida de alta eficiência com detecção por UV (254nm). DFB não foi detectado em nenhuma das amostras analisadas (<0.006mg kg-1 para gordura, <0,014mg kg-1 para músculo, <0,015mg kg-1 para rim, <0,016mg kg-1 para fígado e <0.0006mg kg-1 para leite). Dessa forma, a utilização do princípio ativo conforme recomendado pelo fabricante e em níveis suficientes para se obter o efeito larvicida desejado deve resultar em leite, fígado, rins, gordura e músculos que podem ser considerados seguros para o consumo em termos da presença DFB.

Design, synthesis, and insecticidal evaluation of new benzoylureas containing amide and sulfonate groups based on the sulfonylurea receptor protein binding site for diflubenzuron and glibenclamide.

On the basis of the sulfonylurea receptor (SUR) protein binding site for diflubenzuron and glibenclamide, 15 new benzoylphenylureas containing amide and sulfonate groups were designed and synthesized. Their structures were characterized by (1)H nuclear magnetic resonance (NMR) and elemental analysis [or high-resolution mass spectrometry (HRMS)]. The larvicidal activities of the new compounds against oriental armyworm and diamondback moth were evaluated. Compound II-3 showed nearly the same level of insecticidal activity against oriental armyworm as commercial insecticide flucycloxuron and, thus, emerged as a new lead compound for the development of new benzoylurea insecticides.