Atividade antifúngica e composição química do óleo essencial de Pectis elongata Kunth

Abstract

Essential oils are a rich source of volatile secondary metabolites commonly associated with important biological activities. Among the essential oilproducing plants, the Asteraceae Family stands out, especially in the group the species of the genus Pectis. The present work determined the chemical composition of the essential oil of Pectis elongata, as well as its antifungal activity against fungi of the genus Candida (C. albicans, C. parapisilosis and C. tropicalis). For oil extraction, the hydrodistillation technique was used in Clevenger type apparatus for 2 hours, followed by chemical characterization by GC-MS. Antimicrobial activity assays were performed in vitro using Disc Agar Diffusion and Broth Microdilution techniques. As for the chemical composition of the essential oil, Neral and Geranial, which together give rise to Citral, represent 92.63% of the oil composition. In the agar diffusion disc test, the fungal strains tested were sensitive to oil as well as citral, both presented inhibition halos greater than 40 mm. In the Broth Microdilution test, the essential oil presented MIC values ranging from 0.55 µg mL-1 and 17.6 µg mL-1 and CFM, ranging from 281.3 µg mL-1 to 562.5 µg mL-1 . The citral presented MIC values between 2.19 µg mL-1 and 35 µg mL-1 . Fluconazole showed MIC values ranging from 2 µg mL1 to 64 µg mL-1 and CFM of 128 µg mL-1 for all strains tested. Thus, the essential oil, extracted from fresh P. elongata branches and leaves, exhibited strong antifungal activity, probably due to the high concentration of the Citral compound (formed by the mixture of the Neral and Geranial isomers). synergistically for antimicrobial activity.