Composição química do óleo essencial de Nectandra nitidula Nees et Mart. e atividade biológica em larvas de Aedes aegypti Linnaeus, 1762

Abstract

The genus Nectandra Rol. ex Rottb, belonging to the Lauraceae family, is widely distributed in South America, with occurrences in countries such as Argentina, Brazil, Bolivia, Peru, Paraguay, Venezuela, Colombia, Ecuador, and Guyana. In Brazil, it is one of the main genera in the family, with 46 reported species. Within this context, Nectandra nitidula Nees et Mart. (Lauraceae), commonly known in Brazil as "canela do mato," stands out for its ornamental use in gardening, commercial value of its wood, and the aromatic bark used for making tea. It is a small tree that can reach a height of up to 8 meters, with a trunk diameter ranging from 20 to 30 cm, sparse canopy, and alternate leaves. Given the lack of studies on the chemical composition of this plant, the objective of this research was to determine the chemical composition of the essential oil from Nectandra nitidula Nees et Mart. and evaluate its biological activity on Aedes aegypti larvae. For this purpose, leaves and flowers were collected in Itumirim, MG, Brazil, and the essential oils were extracted by steam distillation. The chemical composition of the oils was determined by gas chromatography-mass spectrometry (GC/MS). The larvicidal activity of the oils was tested on Aedes aegypti larvae at different concentrations. The analysis of the chemical composition of the essential oil extracted from fresh leaves of Nectandra nitidula identified 20 compounds, representing 98.12% of the total, with the main ones being sesquirosefurane (62.51%), τ-Elemene (21.93%), (Z,E)-α-Farnesene (3.14%), allo-Aromadendrene (2.09%), α-Pinene (1.68%), and Spatulenol (1.18%). For the flowers, 15 constituents were identified, representing 97.87% of the total, with the major compounds being sesquirosefurane (78.12%), (Z,E)-α-Farnesene (9.63%), (E)-β-Farnesene (2.33%), and (E,E)-α-Farnesene (2.22%). Regarding the larvicidal activity, it was observed that the mortality of Aedes aegypti larvae exposed to the essential oil from the flowers reached an average of 95% (57 larvae) at the highest concentration (12.96 mg/mL), reaching 100% mortality after 48 hours. After 72 hours of exposure, the dose of 3.6 mg/ml resulted in a mortality of 45 larvae (75%), a number similar to the one obtained with the dose of 9.0 mg/ml, which resulted in 44 deaths (73.3%) after 48 hours. Likewise, the essential oil from the leaves showed an average mortality of 85% (51 larvae) after 24 hours of exposure to the highest concentration (12.96 mg/mL), reaching 100% mortality after 48 hours. After 72 hours of exposure, the dose of 3.6 mg/ml resulted in a mortality of 83.3% (Table 3), a similar number to the one obtained with the dose of 9.0 mg/ml, which resulted in 51 deaths (85%) after 48 hours. These results highlight the larvicidal potential of the essential oil from Nectandra nitidula against the Aedes aegypti mosquito.