Development and validation of an improved oxygen radical absorbance capacity assay using fluorescein as the fluorescent probe

Author(s): Ou B, Hampsch-Woodill M, Prior RL

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.

Similar Articles

Ecdysteroids and a sucrose phenylpropanoid ester from Froelichia floridana

Author(s): Wang P, Li S, Ownby S, Zhang Z, Yuan W, et al.

Isolation and HPLC quantitative analysis of antioxidant flavonoids from Alternanthera tenella Colla

Author(s): Salvador MJ, Ferreira EO, Mertens-Talcott SU, De Castro WV, Butterweck V, et al.

Triterpene saponins from Alternanthera repens

Author(s): Sanoko R, Esperanza G, Pizza C, De Tommasi N

Phytochemical Methods

Author(s): Harbone JB

Iridoid glucosides with free radical scavenging properties from fagraea blumei

Author(s): Cuendet M, Hostettman K, Potterat O, Dyatmko W

The chemistry behind antioxidant capacity assays

Author(s): Huang D, Ou B, Prior RL

Antioxidant capacity and phenolic content of four Myrtaceae plants of the south of Brazil

Author(s): Salvador MJ, de Lourenço CC, Andreazza NL, Pascoal AC, Stefanello ME

New colorimetric cytotoxicity assay for anticancer-drug screening

Author(s): Skehan P, Storeng R, Scudiero D, Monks A, McMahon J, et al.

Flavonoids as antioxidants

Author(s): Pietta PG

Antioxidant capacity of extracts and isolated compounds from Stryphnodendron obovatum Benth

Author(s): Zocoler AMD, Sanches ACC, Albrecht I, Mello JCP

Antioxidant and cytotoxic activities of carob tree fruit pulps are strongly influenced by gender and cultivar

Author(s): Custodio L, Fernandes E, Escapa AL, Fajardo A, Aligue R, et al.

Pfaffia paniculata (Brazilian ginseng) methanolic extract reduces angiogenesis in mice

Author(s): Carneiro CS, Costa-Pinto FA, da Silva AP, Pinello KC, da Silva TC, et al.

Vitexin, an HIF-1alpha inhibitor, has anti-metastatic potential in PC12 cells

Author(s): Choi HJ, Eun JS, Kim BG, Kim SY, Jeon H, et al.

Vitexins, nature-derived lignan compounds, induce apoptosis and suppress tumor growth

Author(s): Zhou Y, Liu YE, Cao J, Zeng G, Shen C, et al.