Abstract:

Essential oil was extracted from leaves of Liquidambar formosana Hance by steam distillation method. Paper disc assay and spread-plate method were used to determine its antimicrobial activity and minimum inhibitory concentration (MIC). Stability of antimicrobial activity of the essential oil to acid, base, heat and ultraviolet ray, as well as its antioxidant activity, were studied. Results showed that the antimicrobial activities of the essential oil from leaves of Liquidambar formosana Hance against five tested microbes were largely different. The essential oil had strong antimicrobial effect against the Gram positive bacteria while weak effect against Gram negative bacteria. The MICs of the essential oil agaginst Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Aspergillus flavus and Penicillium oxalicum were 1.25 %, 0.625 %, 5 %, 2.5 % and 2.5 % respectively. The antimicrobial activities of the essential oil were stable under the conditions of heat and ultraviolet ray, but were unstable under different pH values, strong in acid and weak in base. The essential oil had good antioxidant activity: the higher the concentration of essential oil, the stronger the antioxidant effect.

Key words: leaves of Liquidambar formosana Hance, essential oil, antimicrobial activity, stability, antioxidant activity