Constituintes químicos e efeito ecotoxicológico de extratos de folhas de Eucalyptus urograndis

Abstract

Artificial forests of Eucalyptus produce large amounts of litterbag that by the action of wind and rainwater are dragged into aquatic environment, with consequent alteration of the aquatic ecosystems. For evaluate the ecotoxicological effect of Eucalyptus urograndis litterbag in the aquatic environment; there were prepared organic extracts (hexane, chloroform, ethyl acetate and ethanol), besides an aqueous extract. These polar extracts were tested in vitro against Daphnia similis and D. laevis (Anomopoda: Daphiniidae) as the biological indicators while Chironomus xanthus (Diptera: Chironomidae) was used as bio-indicators for the less polar ones. The testing confirmed the presence of toxic activity in all extracts and indicated the ecotoxicological potential of the E. urograndis leaves in aquatic environments. The test results pointed to the need of new sustainable technologies allow the preservation of aquatic environments located in the vicinity of Eucalyptus sp. fields. Concomitantly to the ecotoxicological studies, hexane and chloroform extracts of litterbag leaves were subjected to phytochemical study, leading to the isolation of 5-hydroxy-4’,7-dimethoxy-6,8-dimethylflavone (eucalyptin), 2-(4´-hydroxyphenyl)ethyl nonacosanoate and long chain alcohol. These two extracts, along with the aqueous extract were derivatized with BSTFA and then analyzed by GC-MS, allowing to detect 25 organic compounds, mainly fatty acids, long chain hydrocarbons, steroids, carbohydrates and long chain alcohols.