Abstract
The ethanol extract of Quercus mongolica leaf was fractionated by various organic solvents, and their antimicrobial and antioxidative activities were investigated against several microorganisms. The ethanol extract of Quercus mongolica leaf at two thousand $\mu\textrm{g}$ per disc showed 17~21mm inhibition zone against Gram postive and Gram negative bacteria. Among the various solvent fractions from ethanol extract of Quercus mongolica leaf, the hexane fraction showed the strongest antimicrobial activity. Minimal inhibitory concentration (MIC) of hexane fraction was 250$\mu\textrm{g}$/mL against Bacillus cereus, 250~500$\mu\textrm{g}$/mL against Listeria monocytogenes, 500$\mu\textrm{g}$/mL against Staphylococcus aureus, Salmonella typhimurium, Escherichia coli O157, and Pseudomonas aeruginosa. Also, the hexane and chloroform fraction had the similar antioxidative activity compared to that of butylated hydroxy toluene(BHT).
