Estudos fitoquímicos e dos efeitos da radiação gama em Echinodorus macrophyllus (chapéu-de-couro) e em óleos essenciais de Inga laurina e Eucalyptus grandis (eucalipto)

Abstract

The plant materials are usually used in the popular medicine with a high degree of microbiological contamination. There are several methods for microbial decontamination of herbal products and gamma radiation has been an alternative which also increases storagetime. Echinodorus macrophyllus, Inga laurina, and Eucalyptus grandis are used by the Brazilian population for various medicinal purposes. In the present study the effect of gamma radiation on fractions containing phenolic compounds, alkaloids and saponins from leaves ofE. macrophyllus was investigated. The use of radiation to microbial decontamination does not cause significant changes in the composition of the samples. Furthermore, the composition of the essential oil of leaves of these three species was evaluated after radiation and the results obtained are not directly connected to the dose of gamma radiation. A dose of 10 kGy was sufficient for complete decontamination of the leaves of Echinodorus macrophyllus. Differentcompounds were identified from the phytochemical study of leaves of E. macrophyllus. The hexane extract mainly provided two triterpenes: stigmasterol and -sitosterol. The fraction containing phenolic compounds provided trans-aconitic acid, trans-ferulic, cafeoiltartronicacid, isovitexin, and isoorientina. Extracts and compounds isolated from E. macrophyllus were submitted to tests of antioxidant activity by scavering the DPPH radical and total antioxidant activity, showing high antioxidant power.