RESUMO

The CHCl3-soluble extract of Piper guanacastensis (Piperaceae) was found to have noteworthy insecticidal activity to Aedes atropalpus mosquito larvae (LC50 80.5 micrograms/mL). Bioassay-guided fractionation afforded methyl 4-hydroxy-3-(3'-methyl-2'-butenyl)benzoate (1) as the major bioactive constituent (LC50 20.5 micrograms/mL). The separation of compound 1 from its transesterification artifact (2), ethyl 4-hydroxy-3-(3'-methyl-2'-butenyl)benzoate, was achieved by recycling reversed-phase HPLC. The flavonoids acacetin, chrysin, and pinostrobin were also isolated from the active fraction but did not display insecticidal properties.

Assuntos

Inseticidas/isolamento & purificação , Parabenos/isolamento & purificação , Plantas Medicinais/química , Aedes , Animais , Cromatografia em Camada Fina , Inseticidas/farmacologia , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Parabenos/farmacologia , Espectrofotometria Ultravioleta