Oxime derivatives with larvicidal activity against Aedes aegypti L.

Abstract

Oximes containing secondary metabolites constitute an important group of bioactive compounds and have been described and frequently updated in the literature due to their pharmacological properties. Thus, the aim of this study was to evaluate the larvicidal activity of a series of fourteen structurally related [1,4]-Benzoquinone mono-oximes on third-instar Aedes aegypti larvae and to investigate structure-activity relationships (SAR) of these compounds. Results of larvicidal assay revealed that all oximes were found to have larvicidal activity. Compound 2,6-dimethyl-[1,4]-benzoquinone oxime tosylate (11) was the most bioactive (LC50 = 9.858 ppm), followed by 2-methyl-[1,4]-benzoquinone oxime tosylate (9) (LC50 = 14.450 ppm). [1,4]-benzoquinone oxime (1) exhibited the lowest potency, with an LC50 = 121.181 ppm. The molecular characteristics which may help to understand the assayed compounds larvicidal activity were identified. SAR indicates that the addition of alkyl groups attached to the ring, number, position in the unsaturated cyclic structure, and size of these groups influence the larvicidal activity. Moreover, the lipophilicity seems to play an important role in increasing the larvicidal effect, because, in general, tosyl-containing products were more potent than products containing free OH.

Formicidal activity of indole derivatives on Atta opaciceps (Borgmeier): Lethal, behavioural and locomotive effects

“…Alteration in the structure of indole and tryptamine resulted in modulation in formicidal activity. Similar results were found, in which synthetic modification of oxime, eugenol, tryptamine, monoterpenes, sulfilimines and amino acid resulted in modulation in insecticidal/larvicidal activities (Barbosa et al, 2012;Lima et al, 2015;Nguyen, Chompoo, & Tawata, 2015;Oliveira et al, 2014;Santos et al, 2011;Zhou et al, 2014).…”

“…The discovery of new compounds by synthetic derivation has been successful in the management of important pest insects (Alvarenga et al., ; Lima et al., ; Sun & Zhou, ; Yang, Li, Wu, Liu, & Chang, ) demonstrating that the variation of chemical radicals in the structure of the compound may be responsible for differences observed in their activities. This relationship between structure and activity may indicate compounds more favourable to biological action and help in the optimization of insecticides by including, for example, characteristics that have a low environmental impact.…”

Synthesis and larvicidal activity of indole derivatives against Aedes aegypti (Diptera: Culicidae)

“…In the present study, we demonstrated the specificity of the larvi- 158.98 to 69.94 μg/ml) (Bharathi et al, 2014), benzoquinone monooximes (LC50 = 9.86 μg/ml) (Lima et al, 2015), R-and S-limonene (LC50 = 27 and 30 μg/ml, respectively) (Santos et al, 2011) and tryptamine (LC50 = 48 μg/ml) (Oliveira et al, 2014). In contrast, N-substituted methyl maleamates exert strong larvicidal effect against A. aegypti (LC50 = 0.36 μg/ml) at 24 hr of treatment (Harburguer et al, 2018).…”

“…Other compounds are less efficient in killing Ae. aegypti larvae after 24 hr of exposure, such as eugenol derivatives (LC50 values ranging from 67 to 113 μg/ml) (Barbosa et al, ), dihydrophenanthroline‐3‐carbonitriles (LC50 values ranging from 158.98 to 69.94 μg/ml) (Bharathi et al, ), benzoquinone mono‐oximes (LC50 = 9.86 μg/ml) (Lima et al, ), R‐ and S‐ limonene (LC50 = 27 and 30 μg/ml, respectively) (Santos et al, ) and tryptamine (LC50 = 48 μg/ml) (Oliveira et al, ). In contrast, N‐ substituted methyl maleamates exert strong larvicidal effect against A. aegypti (LC50 = 0.36 μg/ml) at 24 hr of treatment (Harburguer et al, ).…”

“…The vector is the main target of disease control programmes due to the lack of specific treatments for dengue and vaccines for Zika and chikungunya (Tok et al, 2017;Gilkey et al, 2018). Physical, biological and chemical agents have been used alone or in combination to control the mosquito population (Lima et al, 2015;Plernsub et al, 2016). One viable means is the use of larvicides, which act on the immature form and prevent the development of adult mosquitoes that can transmit arboviruses (Braga, Lima, Da Silva Soares, & Valle, 2004;Carvalho, Honorio, Garcia, & Carvalho, 2017;Chen, Seleena, Chiang, & Lee, 2008).…”