RESUMO
Interactions between low-toxicity terpenoid mosquito repellents and lactic acid are studied at the HF and B3LYP level. The subsequent QSAR study shows that not only the structure of repellents but also the repellent-lactic acid complexes may play an important role. It suggests that further study on interactions between repellents and characteristic compounds from human host may be required in order to understand the repelling mechanism.
Assuntos
Repelentes de Insetos/química , Terpenos/química , Animais , DEET/química , Humanos , Ácido Láctico/química , Relação Quantitativa Estrutura-AtividadeRESUMO
A new class of low-toxicity mosquito repellents is synthesized from alpha- and beta-pinene in terpenoid compounds and preliminary biological tests show promising mosquito repellency. Statistical modeling is built using Codessa in order to reveal the quantitative relationship between the structure and the biological activity and to provide the guidance for further synthetic work.
Assuntos
Mordeduras e Picadas/prevenção & controle , Culicidae/efeitos dos fármacos , Repelentes de Insetos/uso terapêutico , Monoterpenos/uso terapêutico , Relação Quantitativa Estrutura-Atividade , Animais , Monoterpenos Bicíclicos , Compostos Bicíclicos com Pontes , Repelentes de Insetos/química , Repelentes de Insetos/farmacologia , Modelos Químicos , Monoterpenos/síntese química , Monoterpenos/farmacologiaRESUMO
A series of fluorine-containing Pinus diterpenic amides and imines have been synthesised and their structures were confirmed by elemental analysis, IR, (1)H NMR spectroscopy and single crystal X-ray diffraction. Their insect attractant activity to Spodoptera litura were screened by leaf plate method; the results indicated that most fluorine-containing dehydroabietic amides and imines exhibited attractive activity to S. litura, in which dehydroabietic p-trifluoromethyl amide (A6) exhibit seven times the attractive rate compared with blank at the concentration of 0.01 g mL(-1). The fluorine moiety fused to the benzene ring results in decreased attractive rates for amides except (A6), while the effects of fluorine result in increased attractive rates for diterpenic imines.
Assuntos
Amidas/síntese química , Amidas/farmacologia , Flúor/química , Iminas/síntese química , Iminas/farmacologia , Feromônios/síntese química , Feromônios/farmacologia , Amidas/química , Animais , Iminas/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Feromônios/química , Pinus/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Spodoptera/efeitos dos fármacos , Difração de Raios XRESUMO
A series of terpenoid compounds containing a six-member-ring were synthesized from alpha- and beta-pinenes. Antifeedant activity of these terpenoid compounds were tested on the aphid, Lipaphis erysimi (Kalt.), with promising results. Stepwise regression was applied to study the quantitative structure-activity relationship of these compounds. The statistically best model showed that the relative number of O atoms, molecular volume, HOMO-LUMO energy gap, and total charge on the positively charged fragments were the most statistically significant descriptors to predict the antifeedant activity. The possible mechanism of interaction between the antifeedant and aphid chemoreceptor was discussed.