ABSTRACT
O presente trabalho teve por objetivo investigar a atividade antioxidante dos extratos das folhas de Cordia verbenacea obtido por maceração em etanol e partição em solventes orgânicos. O infuso das folhas também foi investigado. O teor de fenóis totais foi avaliado pelo método de Folin-Ciocalteau e o de flavonoides totais pela formação de complexo com cloreto de alumínio. O extrato etanólico, as subfrações e o infuso foram testados em diversas concentrações para determinar a atividade sequestradora de DPPH expressa em termos de sua CE50. A melhor atividade antioxidante encontrada foi para o extrato em acetato de etila, EA, CE50 15,0 ± 0,5 µg.mL-1. Os ensaios espectrofotométricos revelaram altas concentrações de fenóis e de flavonoides no extrato EA. A análise por HPLC-DAD foi realizada para se obter o perfil de UV-Vis dos picos cromatográficos do extrato EA. As características espectrais foram relacionadas a compostos fenólicos e flavonoídicos.
The objective of the present study was to investigate the antioxidant activity of extracts from Cordia verbenacea leaves obtained by maceration in ethanol and partitioned with organic solvents. The infusion of leaves was also investigated. The total phenolic and total flavonoid content was evaluated by the Folin-Ciocalteau method and by the aluminum chloride complex method, respectively. The ethanol extract, the subfractions and the infusion were assayed at various concentrations to determine the DPPH scavenging activity expressed in terms of CE50. The best antioxidant activity was found on the ethyl acetate extract, EA, CE50 15.0 ± 0.5 µg.mL-1. The spectrophotometric assays revealed high phenol and flavonoid concentrations on the EA extract. The HPLC-DAD analysis was performed to reveal the UV-Vis profile of the chromatographic peaks of the EA extract. The UV spectral characteristics were related to phenol and polyphenol compounds.
Subject(s)
Cordia/metabolism , Phenols/analysis , Flavonoids/analysis , Plant Extracts/pharmacology , Chromatography, High Pressure Liquid , Plant Leaves/classification , Antioxidants/pharmacologyABSTRACT
Our investigation of integrated biological control (IBC) started with an assay testing activity of the predacious yeast Saccharomycopsis crataegensis UFMG-DC19.2 against Penicillium digitatum LCP 4354, a very aggressive fungus that causes postharvest decay in oranges. Under unfavourable environmental conditions, the yeast showed a high potential for control (39.9 percent disease severity reduction) of this fungus. This result was decisive for the next step, in which S. crataegensis was tested in association with sodium bicarbonate salt, a generally regarded as safe (GRAS) substance. The yeast was able to survive at different concentrations of the salt (1 percent, 2 percent and 5 percent), and continued to grow for a week at the wound site, remaining viable at high population for 14 days on the fruit surface. The yeast alone reduced the severity of decay by 41.7 percent and sodium bicarbonate alone reduced severity of decay by 19.8 percent, whereas the application of both led to a delay in the development of symptoms from 2 to 10 days. Ingredients of the formulations were not aggressive to fruits since no lesions were produced in control experiments.