Antioxidant activity of extracts from the bark of Chamaecyparis lawsoniana (A. Murray) Parl
2006
Gao, Heng | Shupe, Todd F. | Hse, Chung Y. | Eberhardt, Thomas L.
The bark of Chamaecyparis lawsoniana (A. Murray) Parl. was extracted with methanol and sequentially partitioned with n-hexane, ethyl acetate, n-butanol and deionized water. The antioxidant activities of the four extracts were evaluated using the DPPH radical and ABTS radical cation methods. The total phenolic content of the extracts was determined using the Folin-Ciocalteu method and expressed as gallic acid equivalents (GAE). Butylated hydroxytoluene was used as a positive control in the radical-scavenging activity tests. All the bark extracts showed significant radical-scavenging activity. In the ABTS radical cation assay, n-butanol extracts exhibited the strongest radical-scavenging activity, followed by ethyl acetate, water, and n-hexane extracts. The greatest total phenolic content was 428.54 mg GAE per gram of dry extract and was detected in the n-butanol extract, followed by the ethyl acetate and n-hexane extracts. The antioxidant activities correlate with the amount of phenolics present in these extracts. The ethyl acetate and n-butanol extracts were rich in phenolics and may represent a good source of antioxidants.
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