Identifier

etd-06052007-115906

Degree

Master of Science (MS)

Department

Renewable Natural Resources

Document Type

Thesis

Abstract

This study investigated a Soxhlet extract procedure to separate chemical components in the wood and bark of Port-Orford cedar (POC) (Chamaecyparis lawsoniana). The bio-activities, antioxidant properties, and decay resistance were evaluated. The heartwood extracts were analyzed by gas chromatography-mass spectrometry (GC-MS). Three vitro assays including (1) 1, 1-diphenyl-2-picrylhydrazyl hydrate (DPPH• ) radical scavenging assay, (2) 2,2-azinobis ( 3-ethylbenzothiszoline-6-sulfonic acid) diammonium salt (ABTS) radical cation scavenging ability assay, and (3) metal chelating activity assay were carried out to evaluate the antioxidant activity. The total phenol content of the extracts was determined by the Folin-Ciocalteu method and expressed as Gallic Acid Equivalent (GAE). The results showed that the methanol extracts of the heartwood and the sapwood contained moderate radical scavenging activities, and the inner bark and outer bark extracts showed the most activities. The sapwood extracts demonstrated the strongest chelating metal capability. Among the four partitions of POC bark, the n-Butanol extracts (n-Bu) showed the highest inhibition effect on ABTS+• and the highest amount of total phenolic content, followed by ethyl acetate extracts (EA), water soluble components (Wa) and n-hexane extracts (n-He) subtractions. The correlation suggested that phenolic compounds are likely to contribute to the radical scavenging activity of the methanol extracts. There were three major components found in hexane extracts from the heartwood of POC, which were τ-cadinol, azulene, and τ–muurolol. Hexadecadinoic acid was found in ethyl acetate extracts. Both the n-hexane and ethyl acetate extracts of the heartwood of POC had excellent growth inhibitory effects on white- and brown-rot fungi. The n-hexane extracts showed a higher antifungal index in this assay system, which was significantly higher than the ethyl acetate extracts.

Date

2007

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Todd F. Shupe

DOI

10.31390/gradschool_theses.1693

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