Oviposition deterrence, larvicidal activity and docking of β-germacrene-D-4-ol obtained from leaves of Piper corcovadensis (Piperaceae) against Aedes aegypti

Abstract

The present study compared the chromatographic profile of oils from P. corcovadensis leaves obtained through hydrodistillation, maceration, supercritical fluid, headspace, steam distillation and ultrasound to determine the best method for the obtainment of β-germacrene-D-4-ol. The oviposition deterrent and larvicidal activities of this compound were carried out. The main compounds identified in the oils obtained using these methods were terpinolene, 1-butyl-3,4-methylenedioxybenzene, trans-caryophyllene and β-germacrene-D-4-ol, the proportions of which varied with the extraction method employed. Steam distillation (26.48 ± 0.37%), maceration (25.26 ± 0.39%) and supercritical fluid (24.38 ± 0.47%) were the best methods for extracting β-germacrene-D-4-ol. The oil obtained by maceration had the highest yield and was therefore chosen for the isolation of β-germacrene-D-4-ol. Larvicidal and oviposition assays of isolated compound and the oil obtained by maceration were performed with A. aegypti. Larvicidal activity (LC50) were 18.23 ± 1.19 ppm for β-germacrene-D-4-ol and 6.71 ± 0.16 ppm for the oil. The compound and oil also exhibited oviposition deterrence activity against the mosquito at concentrations of 5, 10 and 50 ppm. Moreover, it could be assumed that the sesquiterpene β-germacrene-D-4-ol achieves oviposition deterrence by interacting with odorant-binding protein 1 (OBP1) in Aedes aegypti, as the highest FitScore was found for this macromolecular target. This suggests how mosquito identifies β-germacrene-D-4-ol at the oviposition site. The findings demonstrate that β-germacrene-D-4-ol and the P. corcovadensis leaf oil obtained by maceration have considerable potential as larvicides and oviposition deterrents for the control of the A. aegypti.