Lan-Ting GU IUFRO Division 5 Conference 5.07 Energy and Chemicals from Forest Biomass/Chemicals from Wood National Taiwan University

Lan-Ting GU*, Shang-Tzen CHANG, Hui-Ting CHANG Antibacterial and Antioxidant Activities of Ethanolic Extract from the Bark of Michelia formosana Lan-Ting GU*, Shang-Tzen CHANG, Hui-Ting CHANG School of Forestry and Resource Conservation, National Taiwan University No. 1 Section 4, Roosevelt Road, Taipei 106, Taiwan Tel +886-2-3366-4651; Fax +886-2-3365-4520 E-mail: r95625008@ntu.edu.tw chtchang@ntu.edu.tw

Exploiting natural bactericide and antioxidant from M. formosana bark Purpose Exploiting natural bactericide and antioxidant from M. formosana bark  Materials : Ethanolic extract of bark from M. formosana Antibacterial activities : Broth microdilution method Antioxidant activities : Total phenolic contents DPPH free scavenging activities Superoxide anion scavenging effects Reducing power assays Trolox equivalent antioxidant capacity (TEAC)  

Results Specimen Bioactivities Antibacterial activities Bark extract Antibacterial activities Exhibiting inhibitory effects on growth of Gram-positive bacteria and one Gram-negative bacterium (E. coli). Antioxidant activities Exhibiting the superior DPPH radical scavenging activity with an EC50 value of 13.08 μg/mL. In the total antioxidant assay, bark extract also showed excellent performance with a TEAC value of 0.61 mM. Four fractions EF showed better antibacterial performance than the other fractions. Minimum inhibitory concentrations (MICs) of EF were 0.125, 0.1, 0.1, 0.25, 0.5 mg/mL against E. faecalis, S. aureus, S. epidermidi, MRSA (Methicillin-resistant S. aureus), and E. coli, respectively. EF, BF, and WF were the most effective fractions with high DPPH radical scavenging activities (EC50 = 14.58, 11.34, and 10.91 μg/mL), reducing power and TEAC values (0.80, 0.73, and 0.57 mM).

Conclusion Bark extract of M. formosana can be utilized as an effective source for antibacterial and antioxidant agents.