Dados do Trabalho

Título

New sesquiterpenes extracted from Amazonian plant with larvicidal activity against Aedes aegypti (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 scenario, strategies for 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 main of this study was to investigate the larvicidal activity of new sesquiterpene 6-ishwarone, as well as the rare compounds ishwarane and ishwarol isolated of essential oil from Piper alatipetiolatum (Piperaceae) against A. aegypti larvae.

Material e Métodos

The essential oil was extracted from the leaves (50 g) of P. alatipetiolatum by the hydrodistillation method and analyzed by GC-MS, GC-FID and 1H 13C NMR. The compounds 6-ishwarone, ishwarane and ishwarol were isolated in 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.

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). In this aspect, this is the first report of the isolation of the 6-ishwarone and their larvicidal activity against A. aegypti larvae, along with rare sesquiterpenes ishwarane and ishwarol are alternative agents of biological control of this mosquito.

Palavras-chave

Piperaceae, Aedes, sesquiterpenes, biological control.