Terpene ketones as natural insecticides against Sitophilus zeamais

HERRERA J.; ZUNINO M.P; DAMBOLENA J.S; PIZZOLITTO R. P.; GAÑAN N.A.; LUCINI E.I.; ZYGADLO J.A

Industrial Crops and Products

ELSEVIER SCIENCE BV

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

0926-6690

The eleven terpene ketones, thymoquinone, (R)-carvone, (S)-carvone, pulegone, dihydrocarvone, men-thone, verbenone, ocimenone, camphor, -thujone and piperitenone, were tested as contact and fumigantinsecticides against adults of Sitophilus zeamais Motschulsky under laboratory conditions. The resultsshow that thymoquinone was found to be more toxic than the other ketones, with lethal doses valuesbeing LC5016.5 g/cm2and LC5013.8 L/L air (24 h after treatment). These ketones were also subjectedto multiple regression analysis and the results derived from the quantitative structure activity relation-ship (QSAR) model suggested two topological indicators, the Balaban and Randic indices, were the bestdescriptors of insecticidal activity of the ketones. However, orbital electronegativity of the carbonyl groupwas the main parameter that connected the inhibition activity of ketones on acetylcholinesterase (AChE).Thus, the insecticidal activity of terpene ketones was primarily explained by the shape of molecules andthe branching of the carbon-atom skeleton, while inhibition of activity of AChE was mainly due to theelectronic descriptors.