QSAR Evaluation of Monoterpenoids' Insecticidal Activity

Abstract

Monoterpenoids are naturally occurring compounds that are found in higher-order plants. These compounds are secondary metabolites that seem to play no major role in the metabolic functioning of the plants. One role of monoterpenoids in the plants is to defend against plant-directed pathogens, herbivores, or competing plant species. These compounds are good leads for synthesis or isolation of more effective insecticides. To accomplish these goals, we developed quantitative structure−activity relationships (QSARs) in order to predict insect toxicity of monoterpenoids and derivatives that have not yet been synthesized or experimentally tested. Correlations were found between toxicity and certain quantum and traditional chemical parameters. We found a linear relationship between LD50 values for house fly toxicity and Mulliken populations in aromatic monoterpenoids. Multiple linear regression of an E-State descriptor and a GETAWAY (GEometry, Topology and Atomic Weights AssemblY) descriptor also showed a relationship with house fly toxicity for a wide range of monoterpenoids. KeywordsQuantitative structure−activity relationship (QSAR), monoterpenoid, insecticide, Mulliken population, quantum descriptor, electrotopological state Disciplines Entomology CommentsReprinted with permission from Journal of Agricultural and Food Chemistry 50 (2002) Monoterpenoids are naturally occurring compounds that are found in higher-order plants. These compounds are secondary metabolites that seem to play no major role in the metabolic functioning of the plants. One role of monoterpenoids in the plants is to defend against plant-directed pathogens, herbivores, or competing plant species. These compounds are good leads for synthesis or isolation of more effective insecticides. To accomplish these goals, we developed quantitative structureactivity relationships (QSARs) in order to predict insect toxicity of monoterpenoids and derivatives that have not yet been synthesized or experimentally tested. Correlations were found between toxicity and certain quantum and traditional chemical parameters. We found a linear relationship between LD 50 values for house fly toxicity and Mulliken populations in aromatic monoterpenoids. Multiple linear regression of an E-State descriptor and a GETAWAY (GEometry, Topology and Atomic Weights AssemblY) descriptor also showed a relationship with house fly toxicity for a wide range of monoterpenoids.

Analysis of Volatile Compounds in the Root Peel, Stem Peel, and Fruit Peel of Pomegranate (Punica granatum) by TDGC/MS

“…The natural pesticidal properties of some monoterpenes make them useful as potential alternative pest control agents as well as good lead compounds for the development of safe, effective, and fully biodegradable pesticides. Monoterpenes possess many pesticidal activities, including insecticidal [36,37], herbicidal [38,39], fungicidal [40,41], and bactericidal [42,43] properties. The insecticidal activity of E. globulus oil containing 1,8-cineole (33.6%), α-pinene (16.9%), D-limonene (5.5%), and linalool acetate (3.4%) as principal components was assessed against the larvae and pupae of the housefly [44].…”

Synthesis, Antimicrobial Activity and in silico Studies on Thymol Esters

“…In some Inula, Doronicum and Pulicaria species, thymyl derivatives rather than sesquiterpenoids are the major root constituents. [20][21][22][23] A review by Talavera-Aleman and collaborators 24 estimated that only 10% of known functionalized thymyl derivatives have been employed in biological testing, showing vast array of diverse activities, such as antimicrobial 4,5,22,[25][26][27] (several papers reporting inhibitory activity against plants' pathogenic fungi 22,26 ), antioxidant, 28 antinociceptive, 29 anti-parasitic (antileishmanial), 30,31 antiprotozoal, 32 insecticidal 33 and piscicidal 34 activity. The usefulness of thymyl derivatives as transdermal drug delivery enhancers has also been reported.…”

“…35 There are several papers reporting isolation, synthesys 4,23,29,33,36 and biological activity 4,5,22,25,[28][29][30]33 of thymyl esters. Grodnitzky and Coats 33 have tested insecticidal activity of thymyl esters of acetic, dichloracetic, trichloroacetic, chlorodifluoroacetic, pivalic and chloropivalic acid on Musca domestica. Mathela and collaborators 4 evaluated antibacterial activity of thymyl esters of acetic, propanoic, 2-methylpropanoic, 3-methylbutanoic, but-2-enoic, benzoic and 2-phenylacetic acids and reported the enhancement in the activity of derivatives in comparison to thymol.…”

“…Keeping in view diverse pharmacological activities of thymol [7][8][9][10][11][12][13][14][15][16][17][18][19] and preliminary results on bioactivity of thymyl derivatives 4,5,22,25,[28][29][30]33 we have set the aim of our study. By making a single modification of a phenolic functionality in thymol we have obtained a series of ester compounds (3a-t), performed their structural characterization, in vitro antimicrobial testing and in silico calculation of physico-chemical, pharmacokinetic and toxicological properties.…”

The Tunisian Artemisia Essential Oils for Reducing Contamination of Stored Cereals by Tribolium castaneum

“…Moreover, among monoterpenes, ketones have more insecticidal effect than alcohols or hydrocarbons (42-45) and even within ketones, toxicity may be at varying degrees (46,47). The main cause of this variation may be due either to geographical or to the physicochemical characteristics (48). Numerous studies have shown the high toxicity of ketones against some stored pests like Sitophilus in fumigant and contact assays (43,46,49).…”