Larvicidal activity of Brunfelsia uniflora extracts on Aedes aegypti larvae

The aim of this study was to evaluate the chemical composition and the larvicidal activity of Brunfelsia uniflora leaf and flower extracts against Aedes aegypti larvae. Twenty-four compounds were found in the leaf extract, and the major compounds were phytol (23.1%), 9,12,15-octadecatrienoic acid, ethyl ester (21.3%), and hexadecanoic acid, ethyl ester (12.8%). In the flower extract, twenty-four compounds were also identified and the major compounds were α-amyrin (35.7%), β-amyrin (16.4%), and (EE)-geranyl linalool (9.6%) by gas chromatography coupled to mass spectrometry. The larvicidal activity was evaluated by larval immersion test. The lethal concentrations (LC) obtained from leaf extract were LC₅₀ = 4.89 and LC_99.9 = 11.14 mg/mL and from flower extract were LC₅₀ = 3.82 and LC_99.9 = 11.03 mg/mL, and the positive control presented LC₅₀ = 0.40 and LC_99.9 = 1.14 mg/mL. Thus, B. uniflora extracts are promising alternatives to control A. aegypti larvae.