Componentes químicos do óleo essencial e do extrato hexânico da taboa (cyperus giganteusvahl.)

Abstract

The species Cyperus gíganteus Vahl, (Cyperaceae), known in Pará as taboa, is an invasive plant found almost everywhere in Brazil, in lowland and flooded areas. Taboa is used by some communities in the state of Pará to make mats, carpets, and screens for doors and windows. Aiming to expand the scientific knowledge about the species, this research plan analyzed the occurrence of variation in the yield and chemical composition of the essential oil of the rhizomes according to seasonality, in addition to the isolation and identification of the main component of the oil, the cyperotundone. The samples were collected quarterly, always in the morning. The rhizomes were dried for 7 days, ground and submitted to hydrodistillation for 3 hours in a Clevenger system. The components were identified by GC and GC/MS, using an OS-5MS capillary column, temperature program: 60°C-240°C (3°C/min) and injector temperature 220°C. The hexanic extract was obtained by percolation, fractionated by column and thin layer chromatography. Cyperotundone was identified by NMR (nuclear magnetic resonance) of proton CH), and carbon thirteen C3C), using GEMINI300/Varian model equipment. The main proton NMR CH) signals that characterized cyperotundone were the following: Me-15: 0.59 (d), Me-14: 1.71 (t), Me-13/Me-12: 1.09 (s)/ 0.72 (s), compatible with those in the literature. As for the essential oil, we observed a small variation in oil yield (0.5% - 0.7%), and significant variations in the percentages of the main components depending on the collection period: cyperene (7.1% - 12.4%), cyperotundone (16.9% - 31.6%). Other components, characteristic of the Cyperaceae family identified in the taboa oil were caryophyllene oxide, trans-pinocarveol, myrtenol and patchulenone.