Natural Products Chemistry & Research

ISSN - 2329-6836

Wan-Hsuan Hsu

Department of Environmental Toxicology, University of California, Davis, California, USA


  • Research Article   
    Antioxidant Activity of Rhubarb (Rheum rhabarbarum L.) Extract and Its Main Component Emodin
    Author(s): Hae Won Jang, Wan-Hsuan Hsu, Matt J Hengel and Takayuki Shibamoto*

    Freeze-dried rhubarb was fractionated using column chromatography with organic solvents (various ratios of water/methanol and acetone). The seven fractions obtained were examined for antioxidant activity using a gas chromatography/malonaldehyde (GC/MA) assay. Emodin (6-methyl-1,3,8-trihydroxyanthraquinone) in each fraction was analyzed by HPLC with a diode array detector. The amounts of emodin found in the seven fractions ranged from 22.4 ± 0.35 μg/g of dried rhubarb (100% methanol eluate) to 0.33 ± 0.01 μg/g (acetone eluate). Emodin was not detected in the fractions eluted with water/methanol mixtures. Among the seven fractions, the fraction eluted with 100% methanol showed the greatest antioxidant activity and contained the highest level of emodin. This fraction exhibited antioxidant activities by 75.4 ± 13.7% at the level of 50 μg/mL, 92.8 ± 0.6.. View More»
    DOI: 10.35248/2329-891X.18.6.316

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