46C-7 |
Composition and antioxidant activity of the essential oil from Curcuma zedoaria |
C. C. CHYAU1, J. L. Mau2, C. C. Chen2, and C. H. Chang1. (1) Department of Food & Nutrition, Hung-Kuang Institute of Technology, 34 Chung-Chie Road, Shalu, Taichung, 433, Taiwan, (2) Department of Food Science, National Chung-Hsing University, 250 Kuokuang Road, Taichung, 40227, Taiwan The dried rhizome of Curcuma zedoaria (CZ) Rosc. (Zingiberaceae), has long been selected to make drinks or to be extracted as medicine. It has been reported that the boiling water extracts of CZ had a moderate antimutagenic activity against benzo[a]pyrene. In a crude ethanolic extract of CZ rhizome, it has been found with the inhibitory activity against OVCAR-3 cells (a human ovarian cancer cell line). These effects might be related to their antioxidant potential. Our objective was to study the antioxidant activity and the composition of essential oil (including its fractionates) from CZ. rhizome. The essential oil from the dried rhizome of CZ using SDE method, and fractionate the essential oil thus obtained into five fractionates using silica gel CC, and then identify the components in the essential oil and its fractionates by GC, RI, MS and authentic compounds. The antioxidant properties, including antioxidant activities, reducing power, scavenging and chelating effects, were determined to compare the effects of the essential oil and its fractionates. Totally, 36 compounds were identified including 17 terpenes, 13 alcohols and 6 ketones in essential oil. Epicurzerenone and curzerene were found in the first and second highest amounts (24.08 and 10.36%, respectively). At 20 mg/mL, the essential oil of CZ exhibited good antioxidant activity, reducing power and scavenging effect on DPPH radical, and low chelating effect on ferrous ion. However, after fractionation, fraction IV showed better antioxidant activity, reducing power and scavenging effect. In fraction IV the major compound was found from 5-isopropylidene-3,8-dimethyl-1(5H)-azulenone. These results suggest that the essential oil of CZ rhizome showed with a moderate antioxidant activity. In this study, after the fractionation of essential oil, the important antioxidant activity was found from 5-isopropylidene-3,8-dimethyl-1(5H)-azulenone.
Session 46C, Food Chemistry: Lipids, antioxidants and emulsifiers
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