RESUMEN
A high performance liquid chromatography (HPLC) method was developed for the simultaneous isolation, on a semi-preparative scale, of chavibetol and methyleugenol from the crude essential oil of P. pseudocaryophyllus leaves. The purity of the isolated compounds and their quantifications were developed using GC/FID. Chavibetol was isolated with high purity (98.7%) and mass recovery (94.6%). The mass recovery (86.4%) and purity (85.3%) of methyleugenol were lower than those of chavibetol. Both compounds were identified on the basis of spectral analysis. The results suggest that the method can provide chavibetol with high purity, mass recovery, and productivity from crude essential, which will be used in bioassays against stored insect pests.
Asunto(s)
Eugenol/análogos & derivados , Pimenta/química , Cromatografía Líquida de Alta Presión , Eugenol/aislamiento & purificación , Aceites Volátiles/química , Hojas de la Planta/química , Aceites de Plantas/químicaRESUMEN
To investigate potential sources of novel grain protector compounds against Sitophilus zeamais (Coleoptera: Curculionidae), which is an important insect pest of stored cereals, this study evaluated the bioactivity of ethanolic extracts (66) prepared from 29 species belonging to 11 different genera of Neotropical Annonaceae. A screening assay demonstrated that the most pronounced bioactive effects on S. zeamais were caused by ethanolic extracts from Annona montana, A. mucosa, A. muricata, and A. sylvatica seeds, causing the death of all weevils exposed, almost complete inhibition of the F1 progeny and a drastic reduction in grain losses. Furthermore, the ethanolic extracts obtained from the leaves of A. montana, A. mucosa, A. muricata, and Duguetia lanceolata, especially A. montana and A. mucosa, demonstrated significant bioactive effects on the studied variables; however, the activity levels were less pronounced than in the seed extracts, and the response was dependent on the concentration used. This study is the first to report the activity of secondary metabolites from D. lanceolata on insects as well as the action of A. sylvatica on pests associated with stored grains.
Para investigar las posibles fuentes de nuevos compuestos protectores de granos contra Sitophilus zeamais (Coleoptera: Curculionidae), una importante plaga de los cereales almacenados, este estudio evaluó la bioactividad de los extractos etanólicos (66) preparados a partir de 29 especies pertenecientes a 11 géneros distintos de Anonaceas Neotropicales. Un ensayo de selección demostró que los efectos bioactivos más relevantes sobre S. zeamais fueron causados por los extractos etanólicos de las semillas de Annona montana, de A. mucosa, de A. muricata y de A. sylvatica, que causaron la muerte de todos los gorgojos expuestos, la inhibición parcial de la progenie F1 y una drástica reducción de las pérdidas de grano. Además, los extractos etanólicos obtenidos de las hojas de A. montana, de A. mucosa, de A. muricata y de Duguetia lanceolata, especialmente de A. montana y de A. mucosa, demostraron efectos bioactivos significativos sobre las variables estudiadas. Sin embargo, los niveles de bioactividad fueron menores en comparación con los extractos de semillas, y la respuesta fue dependiente de la concentración utilizada. Este estudio es el primer relato sobre la actividad de los metabolitos secundarios de D. lanceolata sobre insectos, así como la acción de A. sylvatica sobre plagas asociadas a los granos almacenados.