Date of Award

5-2012

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Food, Nutrition, and Culinary Science

Advisor

Chen, Feng

Committee Member

Dawson , Paul

Committee Member

Walker , Terry

Abstract

O. horridus is an important medicinal and spiritual plant for native peoples where it natively grows. Secondary volatile metabolites which compose the essential oil were isolated by atmospheric simultaneous distillation-solvent extraction (SDE) and headspace solid phase microextraction (HS-SPME) from the bark and leaves of Oplopanax horridus. The differences between the two extraction methods was investigated for their sensitivity, precision and use in separating volatile compounds from sample matrices.The extracts were analyzed by capillary gas chromatography with mass spectrometric detection. Compounds were identified according to their non-isothermal Kovats indexes, mass spectra, or by comparison with analytical standard substances. The bark essential oil was a pale yellow oil that had a higher average yield (w/w) of 0.96±0.06% whereas the leaf extract had a lower essential oil yield of 0.15±0.04% and had a darker brown color. The bark and leaf essential oil extracts were rich (>65% composition) in sesquiterpenes. (E)-nerolidol, τ-cadinol, β-farnesene found in the bark oil and (E)-nerolidol, ar-curcumene, and β-sesquiphylledrene in the leaf oil were important compositional compounds in the essential oils contributing more than 5% of the oils. The coupling of headspace solid-phase microextraction (HS-SPME) under optimized extraction parameters with a highly sensitive gas chromatography mass spectrometry (GC-MS) system allows for rapid sampling and analysis of volatile and semivolatile compounds in complex herbal tissues. Volatile metabolites from the bark and leaves of Oplopanax horridus were absorbed by the polydimethylsiloxane (PDMS) stationary phase via SPME and analyzed by capillary gas chromatography with mass spectrometric detection. The use of HS-SPME extraction and injection of the volatiles of the bark and leaf yielded 48 spectrally unique compounds in the bark and 39 in the leaves. The identified compounds from the bark that had the highest percent concentration were (E)-nerolidol (25.371%), τ-cadinol (15.049%), and spathulenol (8.384%) which comprise 48.804% of the total amount of the bark volatile mixture; similarly, principle compounds of the SPME leaf extract were (E)-nerolidol (37.469%), τ-cadinol (9.315%), ar-turmerol (5.033%), (E)-γ-bisabolene (5.439%), and β-bisabolene (2.730%) which accounted for 59.986% of the volatile mixture.

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