Novel Fluorometric Assay for Hydroxyl Radical Prevention Capacity Using Fluorescein as the Probe

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• 作者：Boxin Ou ; Maureen Hampsch-Woodill ; Judith Flanagan ; Elizabeth K. Deemer ; Ronald L. Prior ; and Dejian Huang
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2002
• 出版时间：May 8, 2002
• 年：2002
• 卷：50
• 期：10
• 页码：2772 - 2777
• 全文大小：80K
• 年卷期：v.50,no.10(May 8, 2002)
• ISSN：1520-5118

文摘

A novel fluorometricmethod has been developed to evaluate hydroxyl radical prevention capacityusing fluorescein (FL) as the probe. The hydroxyl radical is generated by a Co(II)-mediated Fenton-like reaction, and the hydroxyl radical formation under the experimental condition is indirectly confirmedby the hydroxylation of p-hydroxybenzoic acid. The fluorescence decay curve of FL is monitored inthe absence or presence of antioxidant, the area under the fluorescence decay curve (AUC) isintegrated, and the net AUC, which is an index of the hydroxyl radical prevention capacity, is calculatedby subtracting the AUC of the blank from that of the antioxidant. Gallic acid is chosen as a referencestandard, and the activity of sample is expressed as gallic acid equivalents. The method is rigorouslyvalidated through linearity, precision, accuracy, and ruggedness. A wide range of phenolic antioxidantsis analyzed, and the hydroxyl radical prevention capacity is mainly due to the metal-chelating capabilityof the compounds.Keywords: Assay; polyphenolics; hydroxyl radicals; preventive antioxidant; Fenton reaction