Semi-Quantitative Determination of Hydroxyl Radicals by Benzoic Acid Hydroxylation: An Analytical Methodology for Photo-Fenton Systems

Gazi, Sarifuddin; Ananthakrishnan, Rajakumar

doi:10.2174/157341112798472297

Cited by 35 publications

(22 citation statements)

References 23 publications

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“…Hydroxyl radicals generated on photo-activation of Fe(III) complexes were responsible for the formation of salicylic acid which gave a reddish-brown solution of Fe(III)-salicylate complex when methanolic solution of Fe(NO 3 ) 3 •9H 2 O (100 μM) was added externally. 26,27 UV-visible spectra of Fe(III)-salicylate (λ max , 520 nm) was recorded in the presence of complexes (50 μM) exposed to visible light (400-700 nm) for 200 s. Gradual increase in A 520 of Fe(III)-salicylate indicated the generation of OH radical. We plotted the extent of increase of absorbance of Fe(III)-salicylate against time to correlate the relative photo-activated generation of hydroxyl radicals.…”

Section: Hydroxyl Radical Generation Study (Ros)mentioning

confidence: 99%

ROS dependent antitumour activity of photo-activated iron(III) complexes of amino acids

et al. 2019

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Several amino acid-based photo-active monomeric iron(III) complexes of the general formula, [Fe(L) 2 ] − , where L = Schiff base ligands (salisalidene arginine, salicylidenetryptophan, 3,5-di-tert-butyl benzalidine arginine and salicylidene tryptophan) were synthesized, characterized and explored for photoactivated anticancer activity to Chang Liver Cells, HeLa and MCF-7 cells. Complexes exhibited remarkable photo-cytotoxicity with IC 50 value to the extent of 0.7 μM to Chang Liver Cells in visible light and there was a 40-fold enhancement in cytotoxicity in comparison to the cytotoxicity in dark. Complexes were non-toxic to MCF-10A (normal cells) in dark and visible light (IC 50 > 100 μM in dark; IC 50 > 80 μM in visible light) signifying target-specific nature of the anti-tumour activity of the complexes. Increased ROS concentration, as probed by DCFDA assay, in the cancer cells was responsible for apoptotic cell death. Decarboxylation or phenolate-Fe(III) charge transfer of photo-activated iron(III) complexes generating • OH radicals (ROS) were responsible for the apoptosis. Overall, the tumour-selective photo-activated anticancer activity of the amino acidbased iron(III) complexes have shown a promising aspect in developing iron-based photo-chemotherapeutics as the next generation PDT agents.

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Section: Hydroxyl Radical Generation Study (Ros)mentioning

confidence: 99%

ROS dependent antitumour activity of photo-activated iron(III) complexes of amino acids

et al. 2019

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“…This probe, which has been evaluated in sonolytic and photocatalytic systems, leads to 4‐chlorophenol (4‐CP, reaction ) after its reaction with •OH. Alternatively, benzoic acid (BA), whose hydroxylation reaction leads to the formation of the corresponding isomers of HBA (reaction ), was employed as probe to calculate the concentration of the photogenerated •OH in natural waters and those produced in Fenton and photolysis processes . The results dealing with the determination of •OH using BA and pCBA were validated using methanol (reactions and ) and n‐propanol (reactions and ) as molecular probes.…”

Section: Determination Of Reactive Oxygen Species Involved In Advancementioning

confidence: 99%

Insight on the fundamentals of advanced oxidation processes. Role and review of the determination methods of reactive oxygen species

Fernández-Castro

Vallejo

Román

et al. 2015

J of Chemical Tech & Biotech

200

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Advanced oxidation processes (AOPs) have known increased application to treat wastewaters containing recalcitrant compounds that are hardly degraded by conventional technologies. AOPs are characterized by the formation of strong oxidants such as hydroxyl radicals, superoxide anions, hydroperoxyl radicals and singlet oxygen, which react with the contaminant, contributing to its degradation. This paper provides an overview of the determination methods of reactive oxygen species, ROS, in the application of AOPs; the methods developed in the available literature for the detection and quantification of ROS are reviewed as a first step in the assessment and detailed description of the mechanisms involved in the oxidation reactions, focusing on the critical analysis of the main strengths and weaknesses presented by the probe molecules employed in the evaluated studies.

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“…[16][17][18] However, the rst three methods can barely detect cOH quanticationally, although the detection limits of these methods are sufficiently low. In the HPLC method, HPLC is always coupled with an electrochemical detector or uorometric detector, and the operational sequences are complex.…”

Section: Introductionmentioning

confidence: 99%

“…In the HPLC method, HPLC is always coupled with an electrochemical detector or uorometric detector, and the operational sequences are complex. Some researchers tested cOH by the UV-vis spectrophotometric method, [18][19][20][21][22][23] which is inexpensive and convenient. Gazi and Satoh have tested cOH quantitatively in photo-Fenton and Fenton systems, respectively; however, the durations of the tests in their studies was lengthy.…”

Section: Introductionmentioning

confidence: 99%

“…21 The test instrument and radical scavenger in this method are both inexpensive and easily available, and this method can detect cOH quanticationally. However, we accomplished the operations according to the published methods 18 and found that the repeatability of this method was unsatisfactory and that the extraction process had an important effect on the results. In addition, we also determined that the simultaneous extraction of FBBs when extracting diazosulfones using toluene/butanol represented the main interference in the test.…”

Section: Introductionmentioning

confidence: 99%

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Quantitative detection of hydroxyl radicals in Fenton system by UV-vis spectrophotometry

et al. 2015

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The reason for the prominent error in the hydroxyl radical detection method by UV-vis spectrophotometry with fast blue BB salt (FBBs) as the chromogenic agent was detected, and a modified method was proposed.The simultaneous extraction of FBBs in the diazosulfone extraction process was proven to have a distinct influence on the test results. In the modified method, FeSO 4 was adopted to limit the extraction of FBBs by a toluene/butanol extraction agent, which sharply decreased the influence of FBBs on diazosulfone detection. The FBBs amount and extraction time played an important role in its extraction. The appropriate FBBs/MSIA ratio was 50, and the reasonable extraction time was 300 s for the modified method. cOH concentration in the directional decomposition of the Fenton system was detected. The test error was about 7%. This method is quite significant to test cOH quantificationally to better understand Fenton reaction mechanisms and promote the generation of cOH.

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Semi-Quantitative Determination of Hydroxyl Radicals by Benzoic Acid Hydroxylation: An Analytical Methodology for Photo-Fenton Systems

Cited by 35 publications

References 23 publications

ROS dependent antitumour activity of photo-activated iron(III) complexes of amino acids

ROS dependent antitumour activity of photo-activated iron(III) complexes of amino acids

Insight on the fundamentals of advanced oxidation processes. Role and review of the determination methods of reactive oxygen species

Quantitative detection of hydroxyl radicals in Fenton system by UV-vis spectrophotometry

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