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Larvicidal activity of natural and modified triterpenoids against Aedes aegypti (Diptera: Culicidae)
Author(s) -
da Silva Gloria NS,
Trindade Frances TT,
dos Santos Francine,
Gosmann Grace,
e Silva Alexandre A,
Gnoatto Simone CB
Publication year - 2016
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.4221
Subject(s) - aedes aegypti , larvicide , betulinic acid , traditional medicine , larva , biology , ursolic acid , dengue fever , natural product , aedes , toxicology , chemistry , botany , biochemistry , medicine , immunology , genetics
BACKGROUND Insecticide resistance to commonly used substances demands new molecules for the chemical control of the dengue vector Aedes aegypti. Because natural product sources have been an alternative to obtain larvicidal compounds, the aim of this study was to evaluate the triterpenoids betulinic ( BA ) and ursolic ( UA ) acids and their semi‐synthetic derivatives against larval Ae. aegypti . BA , UA , ten derivatives modified at the C‐3 position and a positive control (diflubenzuron) were evaluated. Larvicidal assays were carried out with early fourth‐instar larvae, and mortality was observed between 48 and 96 h. Doses from 200 to 10 ppm were used to calculate lethal concentrations ( LCs ). RESULTS Natural compounds, i.e. UA and BA , had the lowest LCs ( LC 50 of 112 and 142 ppm respectively), except for the modified compound 2b ( LC 50 of 130 ppm). Larvicidal activity increased significantly from 48 to 96 h for all the compounds evaluated, ranging from 20 to 50% after 48 h and from 48 to 76% after 96 h. Some derivatives, e.g. 2a and 2d, had up to a three‐fold larvicidal activity increase from 48 to 96 h. CONCLUSION BA , UA and their derivatives showed larvicidal activity against Ae. aegypti larvae, increasing significantly from 48 to 96 h. The presence of a hydroxyl group is essential for larvicidal potential in these triterpenoids. © 2016 Society of Chemical Industry