The terpene ketones as natural insecticides against Sitophilus zeamais.

JIMENA MARÍA HERRERA; MARÍA PAULA ZUNINO; JOSE SEBASTIAN DAMBOLENA; ROMINA PAOLA PIZZOLITTO; NICOLAS GAÑAN; ENRIQUE IVAN LUCINI; JULIO ALBERTO ZYGADLO

Industrial Crops and Products

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 70 p. 435 - 442

0926-6690

Eleven terpene ketones, thymoquinone, (R)-carvone, (S)-carvone, pulegone, dihydrocarvone, menthone, verbenone, ocimenone, camphor, -thujone and piperitenone were tested as contact and fumigant insecticides against adults of Sitophilus zeamais Motschulsky under laboratory conditions. The results show that thymoquinone was found to be more toxic as compared with other ketones, with lethal doses values of LD50 16.5 g/cm2 and LD50 13.8 L/L air (24h after treatment). The ketones were also subjected to multiple regression analysis. The results derived from QSAR model suggested that topological indices, Balaban and Randic index, are best descriptors of insecticidal activity of ketones. However orbital electronegativity of carbonyl group was the main parameter that connected the inhibition activity of ketones on AChE. Thus, the modeling of the insecticidal activity of terpene ketones is limited to shape of molecules and the branching of the carbon-atom skeleton, while inhibition of activity of AChE is limited to electronic descriptors.