33F-19 |
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H.-J. Kim1, F. CHEN1, C. Wu1, and X. Wang2. (1) Dept. of Food Science & Human Nutrition, Clemson University, P&A Building, Clemson, SC 29634, (2) Department of Genetics & Biochemistry, Clemson University, 101 Jordan Hall, Clemson, SC 29634 Vetiver (Vetiveria zizanoides) oil has been known as a natural cosmetic agent, a popular insect repellent and a strong termiticide. However, due to the complex constituents in vertiver oils, the chemical-activity relationship has not been elucidated and/or studied. Our research aimed to study the antioxidant activity of the vetiver oil and identify the corresponding contributing chemicals. Antioxidant activities of vetiver oil and its components were evaluated by two different in vitro assays: DPPH free radical scavenging assay and Fe2+ metal chelating assay. The results showed that the vetiver oil possessed strong antioxidant activity compared with standard antioxidants such as BHT and a-tocopherol. 10 mL/mL methanol solution of vetiver oil exhibited about 93% free radical scavenging activity in DPPH assay and about 34% metal chelating activity in Fe2+ metal chelating assay, while 1 mM of BHT and a-tocopherol exhibited 73% and 93% in DPPH assay, and 19% and 21% in metal chelating assay, respectively. Among the complex constituents in the vetiver oil, three components, i.e., b-vetivenene, b-vetivone, and a-vetivone, were isolated and tentatively identified using various chromatographic techniques such as silica gel open column chromatography, silica-HPLC and GC/MS. These three compounds also have shown antioxidant activities though their concentration-activity relationship could not be established due to the lack of standards. Nevertheless, these preliminary results in a certain degree suggest that vetiver oil and some of its inherent components might be alternative natural antioxidants that will have wide applications.
Session 33F, Nutraceuticals & Functional Foods: Antioxidants and phytochemical analysis
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