Extraction, Phytochemical Assay And Biological Activities Of Phenolic Compounds From A Medicinal Plant: Eucalyptus Globulus

Extract of Eucalyptus globulus used in phytotherapy was screened in vitro for phenolic compounds content, antioxidant and antibacterial activities. Polyphenols were extracted from trunk bark with methanol (99 %). The proportion of total phenolics was 256 mg CE (catechin equivalents) /g of dry weight (dw). Antioxidant activity of the Eucalyptus globulus trunk bark extract (EGTBE) was evaluated using two methods, the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and hydrogen peroxide scavenging. The extract revealed a concentration – dependent anti-radical activity by inhibiting DPPH radical with 65,17 % for 50 μg / ml. In addition, the result obtained indicates that EGTBE had strong hydrogen peroxide scavenging activity by decrease in absorbance after 20 min. Antibacterial activity of the EGTBE was examined by means of disk-diffusion methods with six bacterial species (Proteus vulgaris, Proteus mirabilis, Escherichia coli, Citrobacter freundii, Staphylococcus aureus, Klebsiella pneumoniae). Extract was effective in inhibiting the growth of the microorganisms except for Staphylococcus aureus and Citrobacter freundii.