| Literature DB >> 11599998 |
B Ou1, M Hampsch-Woodill, R L Prior.
Abstract
An improved method of oxygen radical absorbance capacity (ORAC) assay has been developed and validated using fluorescein (3',6'-dihydroxyspiro[isobenzofuran-1[3H],9'[9H]-xanthen]-3-one) as the fluorescent probe. Our results demonstrate that fluorescein (FL) is superior to B-phycoerythrin. The oxidized FL products induced by peroxyl radical were identified by LC/MS, and the reaction mechanism was determined to follow a classic hydrogen atom transfer mechanism. In addition, methodological and mechanistic comparison of ORAC(FL) with other widely used methods was discussed. It is concluded that, unlike other popular methods, the improved ORAC(FL) assay provides a direct measure of hydrophilic chain-breaking antioxidant capacity against peroxyl radical.Entities:
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Year: 2001 PMID： 11599998 DOI： 10.1021/jf010586o
Source DB: PubMed Journal: J Agric Food Chem ISSN： 0021-8561 Impact factor: 5.279