Dados do Trabalho

Título

Noval sesquiterpenes with larvicidal and antiacetylcholinesterase activities against Aedes aegypti (Diptera: Culicidae)

Introdução

The Aedes aegypti (Culicidae) mosquito is the main transmitter of dengue, zika and chikungunya arboviruses characterized by WHO as an important problem of health in more the 100 countries. Moreover, the resistance to several commercial insecticides is difficult the control A. aegypti and the arboviruses. In this context, strategies for the control of mosquitoes are being focused on natural compounds such as sesquiterpenes extracted from Amazonian plants with biological activities against mosquitoes such as ovicidal, larvicidal, pupicidal, as well as adulticidal

Objetivo (s)

Thus, the aim of this study was to investigate the mechanism and larvicidal activity of new sesquiterpenes 6-ishwarone, ishwarane and ishwarol isolated from essential oil from Piper alatipetiolatum (Piperaceae) against A. aegypti larvae

Material e Métodos

The compounds 6-ishwarone, ishwarane and ishwarol were isolated of the essential oil (50 g) of P. alatipetiolatum using column chromatography using 60-120 mesh silica gel com hexane:ethyl acetate from 9:1 to 7:3. Their structures were confirmed by 1H 13C NMR.The larvicidal activity of 6-ishwarone, ishwarane and ishwarol (10 to 50 ppm) was evaluated against A. aegypti larvae following the WHO protocol with slight modifications. α-Cypermethrin (0.13 to 0.65 ppm) was used with positive control. In addition, their acetylcholinesterase (AChE) activities were evaluated. 

Resultados e Conclusão

The compounds isolated 6-ishwarone (12.54 mg) (LC50 of 26.18 ppm), ishwarane (4.72 mg) (LC50 of 65.910 ppm) and ishwarol (7.62 mg) (LC50 of 27.16 ppm) (p < 0.05) showed larvicidal activity against A. aegypti larvae, with relative potency from 1.435 to 5.917 compared with α-cypermethrin (LC50 of 0.39 ppm). The mechanism of larvicidal action of these compounds occurred by inhibition of AChE (IC50 from 1.93 to 2.65 ppm). This was the first report of the mechanism and larvicidal activity of the 6-ishwarone, ishwarane and ishwarol against A. aegypti larvae. Being, therefore, alternative agents of biological control of this mosquito.

Palavras Chave

Piperaceae; Aedes; sesquiterpenes; biological control.