Chemical composition and larvicidal activity against Aedes aegypti L. (Diptera: Culicidae) of essential oils from leaves, stalks and roots of the Croton nepetaefolius B aill (Euphorbiaceae)

Abstract

Croton nepetaefolius Baill is the aromatic plant native to northeast of Brazil popularly known as “marmeleiro sabiá”. It is used in folk medicine as a stomachic, a carminative and for the treatment of intestinal colic. A total of 26 compounds were obtained by hydrodistillation and identified by GC - MS and CG - FID in the three essential oils samples , being 5 monoterpenes (36.9%), 7 sesquiterpenes (31.8%) and 1 Arylpropanoid (25.7%) in the essential oil of leaves, 6 monoterp enes (16.6%), 8 sesquiterpenes (14.1%) and 2 arylpropanoids (68.6%) in the essential oil of stalks and 7 monoterpenes (5.98%), 4 sesquiterpenes (4.52%) and 2 arylpropanoids (84.9%) in the essential oil of roots . The main constituents in the essential oil o f leaves, stalks and roots are the monoterpene 1, 8 - cineole (26.16%) and the arylpropanoids elemicin (60%) and methyl eugenol (46.31%), respectively. Essential oil of the leaves have been demonstrated larvicidal activity ( LC 50 77.6 mg/mL) , while the essent ial oils of the stalks ( LC 50 134.9 mg/mL) and roots ( LC 50 110 mg/mL) were considered not active. These results can be explained by the presence in the leaves essential oil from C. nepetaefolius of the monoterpenes sabinene, 1,8 - cineole and terpinen - 4 - ol and sesquiterpenes β - caryophyllene and g ermacrene D natural products which have been reported to be active against A. aegypti