Atividade larvicida de metabólitos secundários de plantas provenientes do bioma cerrado tocantinense com efeito em culicídios

Abstract

The Cerrado is considered an important Brazilian biome and covers a large part of the State of Tocantins with forest areas that can provide a great diversity of organic compounds to be explored. Secondary plant metabolics have photochemical importance, producing essential oils, crude oil, resins or plant compounds known as metabolic from their plant structures. The extracts used in the analyzes were collected from plants originating in the city of Gurupi in the southern region of Tocantins. The objective of this work was to select among plant species; Annona glabra L, Anacardium occidentale L., Anacardium humile St Hill, Calophyllum brasiliense Cambess, Copaifera reticulata Ducke, Pterodon emarginatus Vogel and Swinglea glutinosa Merr. the one with the best yield and the best lethal concentration LC50 and LC90 of essential oils and crude oil as well as its molecular composition using gas chromatography analysis coupled with mass spectrometry (GCMS). The oil was obtained by clevenger-type steam drag extraction, hydraulic pressing, organic solvent extraction and core drilling. For mortality tests using the extracts, 3rd instar larvae of the Aedes aegypti mosquito were used at different concentrations diluted in Dimethylsulfoxide (DMSO). Data analysis was performed by linear regression that determined the LC50 and LC90 mortality values and the extraction yields. The best yields were verified using Anacardium occidentale 20.01%, Anacardium humile 19.8% using the brown with organic solvent. The oils with the greatest larvicidal potential were Anacardium humile with LC50 10.81 ppm and LC90 14.16 ppm, followed by Anacardium occidentale LC50 12.08 ppm and LC90 17.84 ppm. The elements identified in the use of CGMS were anacardic acids, cardols, cardanols, palmitic acid, oleic acid, vacenic acid and tridecanoic acid. The major elements found in Anacardium humile were 3-((4,7)- Heptadeca-4,7-dien-1-yl) phenol with 66.93% content, followed by the second 9-Octadecenoic acid with the content of 16, 11%. For Anacardium occidental, the major elements were Phenol with 58.10% followed by (Z)-5-(Pentadec-8-en-1-yl) benzene-1,3-diol 22.92%. The results show lethal activity in the use of all oils at their maximum concentration, the metabolite of Anacardium humile being the one with the best yield and lethal concentration. The results were important to identify that the yields of native species from the Cerrado region of Tocantins have productive potential for crude extract and active metabolic oils as larvicide to be explored in the control of mosquito larvae.