Oxygen radicals photo-induced by ferric nitrilotriacetate complex

Tsuchiya, Koichiro; Akai, Kaori; Tokumura, Akira; Abe, Shinji; Takahashi, Toshiaki; Takiguchi, Yoshiharu; Fukuzawa, Kenji

doi:10.1016/j.bbagen.2005.05.001

Cited by 8 publications

(4 citation statements)

References 52 publications

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“…Hyperfine coupling constants and radical concentrations were obtained by using the computer program Winsim. 25) Other individual conditions are shown in the figure legends.…”

Section: Cytotoxicity Assay At Various Oxygen Concentrationsmentioning

confidence: 99%

Mechanisms of the pH- and Oxygen-Dependent Oxidation Activities of Artesunate

Tsuda

Miyamoto

Hamano

et al. 2018

Biological & Pharmaceutical Bulletin

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Artemisinin was discovered in 1971 as a constituent of the wormwood genus plant (Artemisia annua). This plant has been used as an herbal medicine to treat malaria since ancient times. The compound artemisinin has a sesquiterpene lactone bearing a peroxide group that offers its biological activity. In addition to anti-malarial activity, artemisinin derivatives have been reported to exert antitumor activity in cancer cells, and have attracted attention as potential anti-cancer drugs. Mechanisms that might explain the antitumor activities of artemisinin derivatives reportedly induction of apoptosis, angiogenesis inhibitory effects, inhibition of hypoxia-inducible factor-1α (HIF-1α) activation, and direct DNA injury. Reactive oxygen species (ROS) generation is involved in many cases. However, little is known about the mechanism of ROS formation from artemisinin derivatives and what types of ROS are produced. Therefore, we investigated the iron-induced ROS formation mechanism by using artesunate, a water-soluble artemisinin derivative, which is thought to be the underlying mechanism involved in artesunate-mediated cell death. The ROS generated by the coexistence of iron(II), artesunate, and molecular oxygen was a hydroxyl radical or hydroxyl radical-like ROS. Artesunate can reduce iron(III) to iron(II), which enables generation of ROS irrespective of the iron valence. We found that reduction from iron(III) to iron(II) was activated in the acidic rather than the neutral region and was proportional to the hydrogen ion concentration.

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“…Hyperfine coupling constants and radical concentrations were obtained by using the computer program Winsim. 25) Other individual conditions are shown in the figure legends.…”

Section: Cytotoxicity Assay At Various Oxygen Concentrationsmentioning

confidence: 99%

Mechanisms of the pH- and Oxygen-Dependent Oxidation Activities of Artesunate

Tsuda

Miyamoto

Hamano

et al. 2018

Biological & Pharmaceutical Bulletin

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“…In order to determine the influence of peroxide to achieve maximum bleaching, experiments were undertaken at [dye] = 40 M (Figure 1). In the absence of H 2 O 2 (Figure 1(a)), the dyes underwent considerable bleaching induced by all the metal species (specially phthalocyanine RT and anthraquinone RBB), an effect which may be related either to the presence of O 2 in the solvents used, which can generate reactive species in the presence of metal species [22] or to the direct attack of the metal species on the dyes. This effect stabilizes at dye:complex mol ratios of ca.…”

Section: Resultsmentioning

confidence: 99%

“…There were no previous reports on the use of this complex for the remediation of dye contaminated water. Fe-nta is reduced by light to the ferrous derivative which, in aqueous aerated solution, may form reactive oxygen species [22] via a photo-Fenton process, as shown in Equation 2. In the presence of hydrogen peroxide, the divalent Fe species may undergo further generation of free radicals via the Fenton mechanism (Equation 1), indicating that a synergism exists between light and H 2 O 2 in this situation.…”

Section: Resultsmentioning

confidence: 99%

Trivalent Mn and Fe Complexes for the Degradation of Remazol Dyes

Siguara¹,

Arndt²,

Breno³

2010

JWARP

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Water contamination by Remazol® dyes can be remediated with the use of bleaching metal complexes. In this study, a series of Mn(III) complexes and ferric nitrilotriacetate were found to be useful in the degrada-tion of Remazol Blue, Remazol Turquoise and Remazol Brilliant Blue. The effect of peroxide, pH, time and irradiation on the bleaching of the dyes was studied. Mn(III)-salen complexes were effective in the degrada-tion of the diazo Remazol Blue dye in the presence of a 2-fold excess of hydrogen peroxide. This dye was also effectively bleached by a combination of hydrogen peroxide, ferric nitrilotriacetate and light irradiation. This is the first time well-defined, low molecular weight trivalent metal complexes are applied to the degra-dation of Remazol® dyes

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“…One should also point out that a few related Fe III -Fe II reductions have been reported in the literature, [15][16][17] including the spontaneous reduction of salicylido-type iron(III) complexes to iron(II) analogs, [18] which was proposed to proceed via radical pathways. [19][20][21][22] Accordingly, the present spontaneous reductions may also involve radical processes. Further studies in this area will be aimed at gaining insight into the mechanism of the above reductions through in situ EPR measurements.…”

Section: Discussionmentioning

confidence: 99%

Spontaneous Reduction of High‐Spin Fe^III Complexes Supported by Benzoic Hydrazide Derivative Ligands

et al. 2009

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We report herein experimental evidence for the spontaneous reduction of new high‐spin iron(III) FeIII(L(n))2Cl, L complexes to new high‐spin iron(II) FeII(HL(n))2Cl2 mononuclear complexes. These processes were checked by EPR, cyclovoltammetric, and pseudo‐steady voltammetric studies. Crystal structures of three new complexes (one FeIII and two FeII) were obtained from RX single‐crystal diffraction.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

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Oxygen radicals photo-induced by ferric nitrilotriacetate complex

Cited by 8 publications

References 52 publications

Mechanisms of the pH- and Oxygen-Dependent Oxidation Activities of Artesunate

Mechanisms of the pH- and Oxygen-Dependent Oxidation Activities of Artesunate

Trivalent Mn and Fe Complexes for the Degradation of Remazol Dyes

Spontaneous Reduction of High‐Spin Fe^III Complexes Supported by Benzoic Hydrazide Derivative Ligands

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Oxygen radicals photo-induced by ferric nitrilotriacetate complex

Cited by 8 publications

References 52 publications

Mechanisms of the pH- and Oxygen-Dependent Oxidation Activities of Artesunate

Mechanisms of the pH- and Oxygen-Dependent Oxidation Activities of Artesunate

Trivalent Mn and Fe Complexes for the Degradation of Remazol Dyes

Spontaneous Reduction of High‐Spin FeIII Complexes Supported by Benzoic Hydrazide Derivative Ligands

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Spontaneous Reduction of High‐Spin Fe^III Complexes Supported by Benzoic Hydrazide Derivative Ligands