Determinação do perfil fitoquímico de extrato com atividade antioxidante da espécie medicinal Cordia verbenacea DC. por HPLC-DAD / Phytochemical profile determination from extracts with antioxidant activity of the medicinal species of Cordia verbenacea DC. by HPLC-DAD

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.

Modulation of the norfloxacin resistance in Staphylococcus aureus by Cordia verbenaceae DC.

Background & objectives: Several chemical compounds isolated from natural sources have antibacterial activity and some enhance the antibacterial activity of antibiotics reversing the natural resistance of bacteria to certain antibiotics. In this study, the hexane and methanol extract of Cordia verbenaceae were assessed for antibacterial activity alone and combinated with norfloxacin against the Staphylococcus aureus strain SA1199B. Methods: The minimum inhibitory concentration (MIC) of extracts was assayed using microdilution assay and the modulatory activity was evaluated using plate diffusion assay. Results: The MIC observed varied between 256 to >1024 μg/ml. However, the antibiotic activity of norfloxacin was enhanced in the presence of subinhibitory concentrations of hexane extract of C. verbenaceae (HECV). Interpretations & conclusions: Our results indicate that Cordia verbenaceae DC. can be a source of plant derived products with antibiotic modifying activity.