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Hydroxyl radical scavenging assay of phenolics and flavonoids with a modified cupric reducing antioxidant capacity (CUPRAC) method using catalase for hydrogen peroxide degradation.
Anal Chim Acta. 2008 Jun 02; 616(2):196-206.AC

Abstract

Hydroxyl radicals (OH) generated in the human body may play an important role in tissue injury at sites of inflammation in oxidative stress-originated diseases. As a more convenient, efficient, and less costly alternative to HPLC/electrochemical detection techniques and to the nonspecific, low-yield deoxyribose (TBARS) test, we used a salicylate probe for detecting OH generated by the reaction of iron(II)-EDTA complex with H(2)O(2). The produced hydroxyl radicals attack both the salicylate probe and the hydroxyl radical scavengers that are incubated in solution for 10 min. Added radical scavengers compete with salicylate for the OH produced, and diminish chromophore formation from Cu(II)-neocuproine. At the end of the incubation period, the reaction was stopped by adding catalase. With the aid of this reaction, a kinetic approach was adopted to assess the hydroxyl radical scavenging properties of polyphenolics, flavonoids and other compounds (e.g., ascorbic acid, glucose, mannitol). A second-order rate constant for the reaction of the scavenger with OH could be deduced from the inhibition of colour formation due to the salicylate probe. In addition to phenolics and flavonoids, five kinds of herbs were evaluated for their OH scavenging activity using the developed method. The modified CUPRAC (cupric ion reducing antioxidant capacity) assay proved to be efficient for ascorbic acid, gallic acid and chlorogenic acid, for which the deoxyribose assay test is basically nonresponsive. An important contribution of this developed assay is the inhibition of the Fenton reaction with catalase degradation of hydrogen peroxide so that the remaining H(2)O(2) would neither give a CUPRAC absorbance nor involve in redox cycling of phenolic antioxidants, enabling the rapid assay of polyphenolics.

Authors+Show Affiliations

Department of Chemistry, Faculty of Engineering, Istanbul University, Avcilar 34320, Istanbul, Turkey.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

18482604

Citation

Ozyürek, Mustafa, et al. "Hydroxyl Radical Scavenging Assay of Phenolics and Flavonoids With a Modified Cupric Reducing Antioxidant Capacity (CUPRAC) Method Using Catalase for Hydrogen Peroxide Degradation." Analytica Chimica Acta, vol. 616, no. 2, 2008, pp. 196-206.
Ozyürek M, Bektaşoğlu B, Güçlü K, et al. Hydroxyl radical scavenging assay of phenolics and flavonoids with a modified cupric reducing antioxidant capacity (CUPRAC) method using catalase for hydrogen peroxide degradation. Anal Chim Acta. 2008;616(2):196-206.
Ozyürek, M., Bektaşoğlu, B., Güçlü, K., & Apak, R. (2008). Hydroxyl radical scavenging assay of phenolics and flavonoids with a modified cupric reducing antioxidant capacity (CUPRAC) method using catalase for hydrogen peroxide degradation. Analytica Chimica Acta, 616(2), 196-206. https://doi.org/10.1016/j.aca.2008.04.033
Ozyürek M, et al. Hydroxyl Radical Scavenging Assay of Phenolics and Flavonoids With a Modified Cupric Reducing Antioxidant Capacity (CUPRAC) Method Using Catalase for Hydrogen Peroxide Degradation. Anal Chim Acta. 2008 Jun 2;616(2):196-206. PubMed PMID: 18482604.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Hydroxyl radical scavenging assay of phenolics and flavonoids with a modified cupric reducing antioxidant capacity (CUPRAC) method using catalase for hydrogen peroxide degradation. AU - Ozyürek,Mustafa, AU - Bektaşoğlu,Burcu, AU - Güçlü,Kubilay, AU - Apak,Reşat, Y1 - 2008/04/20/ PY - 2008/02/21/received PY - 2008/04/08/revised PY - 2008/04/10/accepted PY - 2008/5/17/pubmed PY - 2008/8/8/medline PY - 2008/5/17/entrez SP - 196 EP - 206 JF - Analytica chimica acta JO - Anal. Chim. Acta VL - 616 IS - 2 N2 - Hydroxyl radicals (OH) generated in the human body may play an important role in tissue injury at sites of inflammation in oxidative stress-originated diseases. As a more convenient, efficient, and less costly alternative to HPLC/electrochemical detection techniques and to the nonspecific, low-yield deoxyribose (TBARS) test, we used a salicylate probe for detecting OH generated by the reaction of iron(II)-EDTA complex with H(2)O(2). The produced hydroxyl radicals attack both the salicylate probe and the hydroxyl radical scavengers that are incubated in solution for 10 min. Added radical scavengers compete with salicylate for the OH produced, and diminish chromophore formation from Cu(II)-neocuproine. At the end of the incubation period, the reaction was stopped by adding catalase. With the aid of this reaction, a kinetic approach was adopted to assess the hydroxyl radical scavenging properties of polyphenolics, flavonoids and other compounds (e.g., ascorbic acid, glucose, mannitol). A second-order rate constant for the reaction of the scavenger with OH could be deduced from the inhibition of colour formation due to the salicylate probe. In addition to phenolics and flavonoids, five kinds of herbs were evaluated for their OH scavenging activity using the developed method. The modified CUPRAC (cupric ion reducing antioxidant capacity) assay proved to be efficient for ascorbic acid, gallic acid and chlorogenic acid, for which the deoxyribose assay test is basically nonresponsive. An important contribution of this developed assay is the inhibition of the Fenton reaction with catalase degradation of hydrogen peroxide so that the remaining H(2)O(2) would neither give a CUPRAC absorbance nor involve in redox cycling of phenolic antioxidants, enabling the rapid assay of polyphenolics. SN - 1873-4324 UR - https://www.unboundmedicine.com/medline/citation/18482604/Hydroxyl_radical_scavenging_assay_of_phenolics_and_flavonoids_with_a_modified_cupric_reducing_antioxidant_capacity__CUPRAC__method_using_catalase_for_hydrogen_peroxide_degradation_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0003-2670(08)00699-5 DB - PRIME DP - Unbound Medicine ER -