COMPOSIÇÃO QUÍMICA DO ÓLEO ESSENCIAL DA ERVA CIDREIRA (Lippia alba) E ATIVIDADE BIOLÓGICA NO CONTROLE DE NEMATOIDES

Abstract

Plant essential oil is used in several areas, such as in the cosmetic industry and aromatherapy. In addition, some studies have tested the effect of essential oil in the fight against agricultural pests. Thus, this work aimed to identify the compounds present in the essential oil of Lippia alba leaves and to determine the nematicide activity of the oil of this plant. For this purpose, the plant L. alba was collected, also popularly known as lemon balm and the essential oil extraction of the plant was made. The collection of lemon balm was made in the city of Morrinhos - GO and its essential oil was extracted in the Laboratory of Organic Chemistry of the Federal Institute Goiano - Campus Morrinhos, through the hydrodistillation process using the Clevenger apparatus. After the extraction of the essential oil, the chemical composition analysis and the test of the nematicide activity of the oil were performed. The analysis was made from the gas chromatograph device coupled to the mass spectrometer (CG-MS) and the nematicide activity test was made from the preparation of a solution containing J2 of Meloidogyne javanica and a solubilizing solution containing 100 mL of distilled water, 10 mL of ethyl alcohol and 3 mL of Tween. To start the test of the nematicide activity of the oil was prepared in quintuplicates 5 test tubes containing 2 mL of nematode solution and 100 μL of the solubilizing solution and then was added in each of the 4 tubes in quintuplicatas different volumes of essential oil. In the test, the concentrations of 0.2, 0.4, 0.8 and 1.6 μL mL-1 of essential oil were tested. 26 compounds were obtained as a result of the chemical composition of the essential oil. The citral and neral compounds were the compounds with the highest peaks in the chromatogram of the essential oil of the lemon balm. In the biological test, all concentrations of essential oil showed nematicide action, however the value of dead nematodes was very low in relation to the total nematodes in each assay. Thus, the amounts of essential oil used in this research were not efficient for the control of nematodes. However, it is worth mentioning that the essential oil of lemon balm showed nematicide activity and the use of larger amounts than those used in this study may lead to more satisfactory results.