1
|
Weng H, Wang Y, Li F, Muroya Y, Yamashita S, Cheng S. Recovery of platinum group metal resources from high-level radioactive liquid wastes by non-contact photoreduction. J Hazard Mater 2023; 458:131852. [PMID: 37331059 DOI: 10.1016/j.jhazmat.2023.131852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/29/2023] [Accepted: 06/12/2023] [Indexed: 06/20/2023]
Abstract
Recovery of platinum group metals (PGMs) including palladium (Pd), rhodium (Rh), and ruthenium (Ru) from high-level radioactive liquid waste (HLLW) possesses enormous environmental and economic benefits. A non-contact photoreduction method was herein developed to selectively recover each PGM from HLLW. Soluble Pd(II), Rh(III), and Ru(III) ions were reduced to insoluble zero-valent metals and separated from simulated HLLW containing neodymium (Nd) as a representative for lanthanides, another main component in HLLW. Detailed investigation on the photoreduction of different PGMs revealed that Pd(II) could be reduced under 254- or 300-nm UV exposure using either ethanol or isopropanol as reductants. Only 300-nm UV light enabled the reduction of Rh(III) in the presence of ethanol or isopropanol. Ru(III) was the most difficult to reduce, which was only realized by 300-nm UV illumination in isopropanol solution. The effects of pH was also studied, suggesting that lower pH favored the separation of Rh(III) but hindered the reduction of Pd(II) and Ru(III). A delicate three-step process was accordingly designed to achieve the selective recovery of each PGM from simulated HLLW. Pd(II) was reduced by 254-nm UV light with the help of ethanol in the first step. Then Rh(III) was reduced by 300-UV light in the second step after the pH was adjusted to 0.5 to suppress the Ru(III) reduction. In the third step, Ru(III) was reduced by 300-nm UV light after isopropanol was added and the pH was adjusted to 3.2. The separation ratios of Pd, Rh, and Ru exceeded 99.8%, 99.9%, and 90.0%, respectively. Meanwhile, all Nd(III) still remained in the simulated HLLW. The separation coefficients between Pd/Rh and Rh/Ru exceeded 56,000 and 75,000, respectively. This work may provide an alternative method to recover PGMs from HLLW, which minimize the secondary radioactive wastes compared with other approaches.
Collapse
Affiliation(s)
- Hanqin Weng
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026, China; Department of Beam Material Science, SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan; Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakata-shirane, Tokai-mura, Naka-gun, Ibaraki 319-1188, Japan.
| | - Yi Wang
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026, China; Reactor Operation and Application Research Sub-Institute, Nuclear Power Institute of China, Chengdu, Sichuan 610041, China
| | - Fuhai Li
- Suzhou Nuclear Power Research Institute Co. Ltd., Suzhou, Jiangsu 215004, China
| | - Yusa Muroya
- Department of Beam Material Science, SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Shinichi Yamashita
- Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakata-shirane, Tokai-mura, Naka-gun, Ibaraki 319-1188, Japan; Department of Nuclear Engineering and Management, School of Engineering, The University of Tokyo, 4-7-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Sheng Cheng
- Instrumental Analysis Center, Hefei University of Technology, Hefei, Anhui 230009, China
| |
Collapse
|
2
|
Kobayashi K, Ito YT, Kasu Y, Horitani M, Kozawa T. Intramolecular electron transfer from biopterin to Fe II-O 2 complex in nitric oxide synthases occurs at very different rates between bacterial and mammalian enzymes: Direct observation of a catalytically active intermediate. J Inorg Biochem 2023; 238:112035. [PMID: 36327499 DOI: 10.1016/j.jinorgbio.2022.112035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 10/05/2022] [Accepted: 10/17/2022] [Indexed: 11/21/2022]
Abstract
Nitric oxide synthase (NOS) is a cytochrome P450-type mono‑oxygenase that catalyzes the oxidation of L-arginine to nitric oxide. We previously observed that intramolecular electron transfer from biopterin to Fe2+-O2 in Deinococcus radiodurans NOS (DrNOS) using pulse radiolysis. However, the rate of electron transfer in DrNOS (2.2 × 103 s-1) contrasts with a reported corresponding rate (11 s-1) in a mammalian NOS determined using rapid freeze-quench (RFQ) EPR. We applied pulse radiolysis to Bacillus subtilis NOS (bsNOS) and to rat neural NOS oxygenase domain NOS (mNOS). Concurrently, RFQ EPR was used to trap a pterin radical during single-turnover enzyme reactions of the enzymes. By using the pulse radiolysis method, hydrated electrons (eaq-) reduced the heme iron of NOS enzymes. Subsequently, ferrous heme reacted with O2 to form a Fe2+-O2 intermediate. In the presence of pterin, the intermediate of bsNOS was found to convert to other intermediate in the time range of milliseconds. A similar process was determined to have occurred after pulse radiolysis of the pterin-bound mNOS, though the rate was much slower. The intermediates of all of the NOS enzymes further converted to the original ferric form in the time range of seconds. When using the RFQ method, pterin radicals were formed very rapidly in both DrNOS and bsNOS in the time range of milliseconds. In contrast, the pterin radical in mNOS was observed to form slowly, at a rate of ∼20 s-1.
Collapse
Affiliation(s)
- Kazuo Kobayashi
- The Institute of Scientific and Industrial Research, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan.
| | - Yuko Tsutsui Ito
- The Institute of Scientific and Industrial Research, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Yuri Kasu
- Department of Applied Biochemistry and Food Science, Saga University, Honjo-machi Saga, 840-8502, Japan
| | - Masaki Horitani
- Department of Applied Biochemistry and Food Science, Saga University, Honjo-machi Saga, 840-8502, Japan; The United Graduate School of Agricultural Sciences, Kagoshima University, 1-21-24 Korimoto, Kagoshima, Kagoshima 890-0065, Japan
| | - Takahiro Kozawa
- The Institute of Scientific and Industrial Research, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| |
Collapse
|
3
|
Grills DC, Layne BH, Wishart JF. Coupling Pulse Radiolysis with Nanosecond Time-Resolved Step-Scan Fourier Transform Infrared Spectroscopy: Broadband Mid-Infrared Detection of Radiolytically Generated Transients. Appl Spectrosc 2022; 76:1142-1153. [PMID: 35414202 DOI: 10.1177/00037028221097429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We describe the first implementation of broadband, nanosecond time-resolved step-scan Fourier transform infrared (S2-FT-IR) spectroscopy at a pulse radiolysis facility. This new technique allows the rapid acquisition of nano- to microsecond time-resolved infrared (TRIR) spectra of transient species generated by pulse radiolysis of liquid samples at a pulsed electron accelerator. Wide regions of the mid-infrared can be probed in a single experiment, which often takes < 20-30 min to complete. It is therefore a powerful method for rapidly locating the IR absorptions of short-lived, radiation-induced species in solution, and for directly monitoring their subsequent reactions. Time-resolved step-scan FT-IR detection for pulse radiolysis thus complements our existing narrowband quantum cascade laser-based pulse radiolysis-TRIR detection system, which is more suitable for acquiring single-shot kinetics and narrowband TRIR spectra on small-volume samples and in strongly absorbing solvents, such as water. We have demonstrated the application of time-resolved step-scan FT-IR spectroscopy to pulse radiolysis by probing the metal carbonyl and organic carbonyl vibrations of the one-electron-reduced forms of two Re-based CO2 reduction catalysts in acetonitrile solution. Transient IR absorption bands with amplitudes on the order of 1 × 10-3 are easily detected on the sub-microsecond timescale using electron pulses as short as 250 ns.
Collapse
Affiliation(s)
- David C Grills
- Chemistry Division, 8099Brookhaven National Laboratory, Upton, NY, USA
| | - Bobby H Layne
- Chemistry Division, 8099Brookhaven National Laboratory, Upton, NY, USA
| | - James F Wishart
- Chemistry Division, 8099Brookhaven National Laboratory, Upton, NY, USA
| |
Collapse
|
4
|
Szreder T, Kisała J, Bojanowska-Czajka A, Kasperkowiak M, Pogocki D, Bobrowski K, Trojanowicz M. High energy radiation - Induced cooperative reductive/oxidative mechanism of perfluorooctanoate anion (PFOA) decomposition in aqueous solution. Chemosphere 2022; 295:133920. [PMID: 35143857 DOI: 10.1016/j.chemosphere.2022.133920] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 02/04/2022] [Accepted: 02/06/2022] [Indexed: 06/14/2023]
Abstract
The mechanism of high-energy radiation induced degradation of perfluorooctanoate anion (PFOA, C7F15COO-) was investigated in aqueous solutions. Identification and quantification of transient species was performed by pulse radiolysis and of final products by gas and ion chromatography, electrochemical method using fluoride ion-selective electrode and ESI-MS after γ-radiolysis. Experimental data were further supported by kinetic simulations and quantum mechanical calculations. Radiation induced degradation of PFOA includes as a primary step one-electron reduction of PFOA by hydrated electrons (e-aq) resulting in formation of [C7F15COO-]●-. The rate constants of this reaction were found to be in the range 7.7 × 107-1.3 × 108 M-1s-1 for ionic strength of the solutions in the range 0.01-0.1 M and were independent of pH of the solutions. At pH > 11 [C7F15COO-]●- tends to defluorination whereas at lower pH undergoes protonation forming [C7F15COOH]•-. A sequence of consecutive reactions involving [C7F15COOH]•- leads to PFOA regeneration what explains a high radiation resistance of PFOA at moderately acidic solutions. A simultaneous presence of oxidizing transient species (●OH) in the irradiated system enhanced decomposition of (C7F14)·COO- as well as [C7F15COOH]•-. The key steps in this complex radical mechanism are the reactions of both these radical anions with ●OH leading to semi-stable products which further undergo consecutive thermal reactions. On the other hand, direct reactions of PFOA with ●OH and ●H were found to be relatively slow (7 × 103 and <4 × 107 M-1s-1, respectively) and do not play relevant role in PFOA degradation. Collected for the first time results, such as dependence of selected reaction rate constants and selected products radiation chemical yields on pH as well as finding of several semi-stable products, missing in previous studies, indicate incompleteness of published earlier reaction pathways of PFOA degradation. The presented overall mechanism explains experimental results and verifies previously suggested mechanisms found in the literature.
Collapse
Affiliation(s)
- Tomasz Szreder
- Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195, Warsaw, Poland.
| | - Joanna Kisała
- College of Natural Science, University of Rzeszów, Pigonia 1, 35-310, Rzeszów, Poland
| | | | - Małgorzata Kasperkowiak
- Centre for Advanced Technologies, Adam Mickiewicz University, Uniwersytetu Poznańskiego 10, 61-614, Poznań, Poland
| | - Dariusz Pogocki
- Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195, Warsaw, Poland
| | - Krzysztof Bobrowski
- Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195, Warsaw, Poland
| | - Marek Trojanowicz
- Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195, Warsaw, Poland; Department of Chemistry, University of Warsaw, Pasteura 1, 02-092, Warsaw, Poland
| |
Collapse
|
5
|
Ramos DR, Fernández MI, Furtmüller PG, Obinger C, García MV, Santaballa JA, Canle M. Effect of ionizing radiation on human myeloperoxidase: Reaction with hydrated electrons. J Photochem Photobiol B 2022; 226:112369. [PMID: 34864529 DOI: 10.1016/j.jphotobiol.2021.112369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 10/31/2021] [Accepted: 11/24/2021] [Indexed: 06/13/2023]
Abstract
Myeloperoxidase (MPO) is a myeloid-lineage restricted enzyme largely expressed in the azurophilic granules of neutrophils. It catalyses the formation of reactive oxygen species, mainly hypochlorous acid, contributing to anti-pathogenic defense. Disorders in the production or regulation of MPO may lead to a variety of health conditions, mainly of inflammatory origin, including autoimmune inflammation. We have studied the effect of ionizing radiation on the activity of MPO, as measured by the capacity retained by the enzyme to produce hypochlorous acid as reactive oxygen species after exposure to successive doses of solvated electrons, the strongest possible one-e- reducing agent in water. Chlorination activity was still present after a very high irradiation dose, indicating that radiation damage does not take place at the active site, hindered in the core of MPO structure. Decay kinetics show a dependence on the wavelength, supporting that the process must occur at peripheral functional groups situated on external and readily accessible locations of the enzyme. These results are relevant to understand the mechanism of resistance of our innate anti-pathogenic defense system and also to get insight into potential strategies to regulate MPO levels as a therapeutic target in autoimmune diseases.
Collapse
Affiliation(s)
- Daniel R Ramos
- Universidade da Coruña, Chemical Reactivity & Photoreactivity Group (REACT!), Department of Chemistry, CICA & Faculty of Sciences, A Zapateira s/n, E-15071 A Coruña, Spain.
| | - M Isabel Fernández
- Universidade da Coruña, Chemical Reactivity & Photoreactivity Group (REACT!), Department of Chemistry, CICA & Faculty of Sciences, A Zapateira s/n, E-15071 A Coruña, Spain
| | - Paul G Furtmüller
- Department of Chemistry, Institute of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Christian Obinger
- Department of Chemistry, Institute of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - M Victoria García
- Universidade da Coruña, Chemical Reactivity & Photoreactivity Group (REACT!), Department of Chemistry, CICA & Faculty of Sciences, A Zapateira s/n, E-15071 A Coruña, Spain
| | - J Arturo Santaballa
- Universidade da Coruña, Chemical Reactivity & Photoreactivity Group (REACT!), Department of Chemistry, CICA & Faculty of Sciences, A Zapateira s/n, E-15071 A Coruña, Spain
| | - Moisés Canle
- Universidade da Coruña, Chemical Reactivity & Photoreactivity Group (REACT!), Department of Chemistry, CICA & Faculty of Sciences, A Zapateira s/n, E-15071 A Coruña, Spain.
| |
Collapse
|
6
|
Dhayagude AC, Newase SK, Joshi SS, Kapadnis BP, Kapoor S. Preparation of silver nanoparticles in the presence of polyoxometalates. Mater Sci Eng C Mater Biol Appl 2019; 94:437-444. [PMID: 30423727 DOI: 10.1016/j.msec.2018.09.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 08/08/2018] [Accepted: 09/04/2018] [Indexed: 01/29/2023]
Abstract
The mechanisms of reduction of silver ions and subsequently oxidation of silver atoms in the presence of polyoxometalates (POMs) are discussed. A step-by-step room temperature electron reduction of silver ions and its subsequent reactions has been used in this work to monitor oxidation of silver atoms and its clusters. The silver atoms can transfer electron to POMs is revealed by decrease in the yield of silver clusters and increase in their decay rates. The results of continuous γ-irradiation are compared using UV-visible (UV-Vis) absorption spectra, underlying the effect of silver atoms accumulation in the absence of POMs. Silver nanoparticles (Ag NPs) prepared by reduced silicotungstic acid (STA) were used as Raman substrate and also for antibacterial studies against panel of human pathogenic bacteria. The Ag NPs exhibited antibacterial activity against both Gram-positive and Gram-negative bacterial pathogens evaluated by well diffusion assay. The inhibition zones were within the range of 10 to 14 mm. We have also explored the surface enhanced Raman scattering (SERS) activity of the Ag NPs substrates using 1.0 × 10-7 M solution of crystal violet (CV) as Raman probe molecule. It was possible to detect SERS spectral pattern of CV on Ag NPs substrate with a high signal-to-noise ratio. Both SERS and antibacterial studies show that this simple, low cost, and greener method for synthesizing Ag NPs may be valuable in future studies about SERS sensor development and bio-applications.
Collapse
Affiliation(s)
- Akshay C Dhayagude
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India; Department of Chemistry, Savitribai Phule Pune University, Pune 411007, India
| | - Sandeep K Newase
- Department of Microbiology, Savitribai Phule Pune University, Pune 411007, India
| | - Satyawati S Joshi
- Department of Chemistry, Savitribai Phule Pune University, Pune 411007, India
| | - Balasaheb P Kapadnis
- Department of Microbiology, Savitribai Phule Pune University, Pune 411007, India
| | - Sudhir Kapoor
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
| |
Collapse
|
7
|
Ogura M, Endo R, Ishikawa H, Takeda Y, Uchida T, Iwai K, Kobayashi K, Ishimori K. Redox-dependent axial ligand replacement and its functional significance in heme-bound iron regulatory proteins. J Inorg Biochem 2018; 182:238-248. [PMID: 29449016 DOI: 10.1016/j.jinorgbio.2018.01.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/07/2017] [Accepted: 01/08/2018] [Indexed: 11/29/2022]
Abstract
Iron regulatory proteins (IRPs), regulators of iron metabolism in mammalian cells, control the translation of proteins involved in iron uptake, storage and utilization by binding to specific iron-responsive element (IRE) sequences of mRNAs. Two homologs of IRPs (IRP1 and IRP2) have a typical heme regulatory motif (HRM), a consensus sequence found in "heme-regulated proteins". However, specific heme binding to HRM has been reported only for IRP2, which is essential for oxidative modification and loss of binding to target mRNAs. In this paper, we confirmed that IRP1 also specifically binds two molar equivalents of heme, and found that the absorption and resonance Raman spectra of heme-bound IRP1 were quite similar to those of heme-bound IRP2. This shows that the heme environmental structures in IRP1 are close to those of proteins using heme as a regulatory molecule. Pulse radiolysis experiments, however, clearly revealed an axial ligand exchange from Cys to His immediately after the reduction of the heme iron to form a 5-coordinate His-ligated heme in heme-bound IRP2, whereas the 5-coordinate His-ligated heme was not observed after the reduction of heme-bound IRP1. Considering that the oxidative modification is only observed in heme-bound IRP2, but not IRP1, probably owing to the structural flexibility of IRP2, we propose that the transient 5-coordinate His-ligated heme is a prerequisite for oxidative modification of heme-bound IRP2, which functionally differentiates heme binding of IRP2 from that of IRP1.
Collapse
Affiliation(s)
- Mariko Ogura
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Ryosuke Endo
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan; Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8530, Japan
| | - Haruto Ishikawa
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8530, Japan
| | - Yukiko Takeda
- Molecular and Cellular Physiology, Graduate School of Medicine, Kyoto University, Kyoto 606-8561, Japan
| | - Takeshi Uchida
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-8628, Japan; Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Kazuhiro Iwai
- Molecular and Cellular Physiology, Graduate School of Medicine, Kyoto University, Kyoto 606-8561, Japan
| | - Kazuo Kobayashi
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - Koichiro Ishimori
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-8628, Japan; Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.
| |
Collapse
|
8
|
Anderson RF, Li D, Hunter FW. Antagonism in effectiveness of evofosfamide and doxorubicin through intermolecular electron transfer. Free Radic Biol Med 2017; 113:564-570. [PMID: 29111232 DOI: 10.1016/j.freeradbiomed.2017.10.385] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 10/25/2017] [Accepted: 10/26/2017] [Indexed: 12/27/2022]
Abstract
Hypoxic cells pose a problem in anticancer chemotherapy, in which often drugs require oxygen as an electron acceptor to bring about the death of actively cycling cells. Bioreductive anticancer drugs, which are selectively activated in the hypoxic regions of tumours through enzymatic one-electron reduction, are being developed for combination with chemotherapy-, radiotherapy- and immunotherapy-containing regimens to kill treatment-resistant hypoxic cells. The most clinically-advanced bioreductive drug, evofosfamide (TH-302), which acts by releasing a DNA-crosslinking mustard, failed to extend overall survival in combination with doxorubicin, a topoisomerase II inhibitor, for advanced soft tissue sarcoma in a pivotal clinical trial. However, the reasons for the lack of additive efficacy with this combination are unknown. Here, we show that the radical anion of evofosfamide undergoes electron transfer to doxorubicin in kinetic competition to fragmentation of the radical anion, thus suppressing the release the cytotoxic mustard. This electron transfer process may account, at least in part, for the lack of overall survival improvement in the recent clinical trial. This study underlines the need to consider both redox and electron transfer chemistry when combining bioreductive prodrugs with other redox-active drugs in cancer treatment.
Collapse
Affiliation(s)
- Robert F Anderson
- Auckland Cancer Society Research Centre, Faculty of Health and Medical Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand; School of Chemical Sciences, Faculty of Science, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
| | - Dan Li
- Auckland Cancer Society Research Centre, Faculty of Health and Medical Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Francis W Hunter
- Auckland Cancer Society Research Centre, Faculty of Health and Medical Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| |
Collapse
|
9
|
Dębski D, Smulik R, Zielonka J, Michałowski B, Jakubowska M, Dębowska K, Adamus J, Marcinek A, Kalyanaraman B, Sikora A. Mechanism of oxidative conversion of Amplex® Red to resorufin: Pulse radiolysis and enzymatic studies. Free Radic Biol Med 2016; 95:323-32. [PMID: 27021961 PMCID: PMC5697983 DOI: 10.1016/j.freeradbiomed.2016.03.027] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 03/08/2016] [Accepted: 03/24/2016] [Indexed: 01/11/2023]
Abstract
Amplex® Red (10-acetyl-3,7-dihydroxyphenoxazine) is a fluorogenic probe widely used to detect and quantify hydrogen peroxide in biological systems. Detection of hydrogen peroxide is based on peroxidase-catalyzed oxidation of Amplex® Red to resorufin. In this study we investigated the mechanism of one-electron oxidation of Amplex® Red and we present the spectroscopic characterization of transient species formed upon the oxidation. Oxidation process has been studied by a pulse radiolysis technique with one-electron oxidants (N3(•), CO3(•-),(•)NO2 and GS(•)). The rate constants for the Amplex® Red oxidation by N3(•) ((2)k=2.1·10(9)M(-1)s(-1), at pH=7.2) and CO3(•-) ((2)k=7.6·10(8)M(-1)s(-1), at pH=10.3) were determined. Two intermediates formed during the conversion of Amplex® Red into resorufin have been characterized. Based on the results obtained, the mechanism of transformation of Amplex® Red into resorufin, involving disproportionation of the Amplex® Red-derived radical species, has been proposed. The results indicate that peroxynitrite-derived radicals, but not peroxynitrite itself, are capable to oxidize Amplex® Red to resorufin. We also demonstrate that horseradish peroxidase can catalyze oxidation of Amplex® Red not only by hydrogen peroxide, but also by peroxynitrite, which needs to be considered when employing the probe for hydrogen peroxide detection.
Collapse
Affiliation(s)
- Dawid Dębski
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Renata Smulik
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Jacek Zielonka
- Department of Biophysics and Free Radical Research Center, Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI 53226, United States.
| | - Bartosz Michałowski
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Małgorzata Jakubowska
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Karolina Dębowska
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Jan Adamus
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Andrzej Marcinek
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Balaraman Kalyanaraman
- Department of Biophysics and Free Radical Research Center, Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI 53226, United States
| | - Adam Sikora
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland.
| |
Collapse
|
10
|
Getoff N. Pulse Radiolysis Using Very-high-energy Ions for Optimizing Cancer Therapy. In Vivo 2016; 30:119-121. [PMID: 26912822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Cancer therapy by means of high-energy ions is very efficient. As a consequence of the linear-energy-transfer effect only a negligible part of the produced free radicals can escape combination processes to form molecular products and to cause undesired side processes. Positrons (e⁺) and γ-rays, generated by the nuclear interaction of high-energy ions in the medium, serve in monitoring the radiation dose absorbed by the tumor. However, due to the dipole nature of water molecules a small proportion of thermalized positrons (e⁺th) can become solvated (e⁺aq). Hence, they are stabilized, live longer and can initiate side reactions. In addition, positronium (Ps), besides solvated electrons (e⁺aq), can be generated and involved in the reaction mechanisms. For a better understanding of the reaction mechanisms involved and to improve cancer therapy, a time-resolved pulse radiolysis instrument using high-energy particles is discussed here. The proposed method is examined and recommended by CERN experts. It is planned to be realized at the MedAustron Radiation Therapy and Research Centre in Wiener Neustadt, Austria.
Collapse
Affiliation(s)
- Nikola Getoff
- Section of Radiation Biology, Department for Nutritional Sciences, Faculty of Life Science, The University of Vienna, Vienna, Austria
| |
Collapse
|
11
|
Bojanowska-Czajka A, Kciuk G, Gumiela M, Borowiecka S, Nałęcz-Jawecki G, Koc A, Garcia-Reyes JF, Ozbay DS, Trojanowicz M. Analytical, toxicological and kinetic investigation of decomposition of the drug diclofenac in waters and wastes using gamma radiation. Environ Sci Pollut Res Int 2015; 22:20255-20270. [PMID: 26308920 PMCID: PMC4679101 DOI: 10.1007/s11356-015-5236-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 08/11/2015] [Indexed: 06/04/2023]
Abstract
The radiolytic decomposition of the drug diclofenac (DCF), and in limited extent, also two other widely used drugs, ibuprofen and carbamazepine, was examined using liquid chromatography (LC) methods. The efficiency of DCF decomposition was examined in function of the absorbed dose of gamma radiation, and also in the presence of selected scavengers of radicals, which are commonly present in natural waters and wastes. Three different tests were employed for the monitoring of toxicity changes in the irradiated DCF solutions. The LC/mass spectrometry (MS) was used for the determination of products of DCF radiolysis. Using pulse-radiolysis method with the spectrophotometric detection, the rate constant values were determined for reactions of DCF with the main products of water radiolysis: hydroxyl radicals (1.24 ± 0.02) × 10(10) M(-1) s(-1) and hydrated electrons (3.1 ± 0.2) × 10(9) M(-1) s(-1). Their values indicate that both oxidative and reductive processes in radiolytic decomposition of DCF can take place in irradiated diluted aqueous solutions of DCF. The possibility of decomposition of all examined analytes was investigated in samples of river water and hospital waste. Compared to the previous studies, the conducted measurements in real samples were carried out at the concentration levels, which are close to those reported earlier in environmental samples. Graphical abstract ᅟ.
Collapse
Affiliation(s)
- A Bojanowska-Czajka
- Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195, Warsaw, Poland.
| | - G Kciuk
- Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195, Warsaw, Poland
| | - M Gumiela
- Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195, Warsaw, Poland
| | - S Borowiecka
- Department of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warsaw, Poland
| | - G Nałęcz-Jawecki
- Department of Environmental Health Sciences, Medical University of Warsaw, Warsaw, Poland
| | - A Koc
- Department of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warsaw, Poland
| | - J F Garcia-Reyes
- Faculty of Physical and Analytical Chemistry, University of Jaen, Jaen, Spain
| | - D Solpan Ozbay
- Department of Chemistry, Hacettepe University, Ankara, Turkey
| | - M Trojanowicz
- Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195, Warsaw, Poland
- Department of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warsaw, Poland
| |
Collapse
|
12
|
Wu B, Zhu D, Zhang S, Lin W, Wu G, Pan B. The photochemistry of carbon nanotubes and its impact on the photo-degradation of dye pollutants in aqueous solutions. J Colloid Interface Sci 2014; 439:98-104. [PMID: 25463180 DOI: 10.1016/j.jcis.2014.10.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Revised: 10/09/2014] [Accepted: 10/15/2014] [Indexed: 10/24/2022]
Abstract
It is reported that carbon nanotubes (CNTs) could either generate reactive oxygen species (ROS) under light irradiation or serve as high-efficient scavenger for ROS. However, it is unclear which role predominates as CNTs enter into aquatic environment. To answer this question, a systematic study of the photochemistry of a pristine and a surface-functionalized CNTs in aqueous suspensions was investigated with both time-resolved and steady state analytical approaches. The transient absorption spectra demonstrate that CNTs could be photo-ionized and trap hydrated electrons upon high energy irradiation. In steady state UV irradiation, CNTs could promote the generation of ROS, such as (1)O2 and OH. However, in the presence of H2O2, the OH scavenging effect predominated in the aqueous suspensions of CNTs. The presence of CNTs suppressed the photo-degradation of dye pollutants, as an integrated result of inner filter effect, adsorption effect, and ROS generation and scavenging effect. The results provide useful information for the understanding of the environmental implications of CNTs.
Collapse
Affiliation(s)
- Bingdang Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Dunxue Zhu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Shujuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
| | - Weizhen Lin
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201203, China
| | - Guozhong Wu
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201203, China
| | - Bingcai Pan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| |
Collapse
|
13
|
Samuni Y, Wink DA, Krishna MC, Mitchell JB, Goldstein S. Suberoylanilide hydroxamic acid radiosensitizes tumor hypoxic cells in vitro through the oxidation of nitroxyl to nitric oxide. Free Radic Biol Med 2014; 73:291-8. [PMID: 24880052 PMCID: PMC7670884 DOI: 10.1016/j.freeradbiomed.2014.05.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 05/13/2014] [Accepted: 05/20/2014] [Indexed: 01/05/2023]
Abstract
The pharmacological effects of hydroxamic acids are partially attributed to their ability to serve as HNO and/or NO donors under oxidative stress. Previously, it was concluded that oxidation of the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) by the metmyoglobin/H2O2 reaction system releases NO, which was based on spin trapping of NO and accumulation of nitrite. Reinvestigation of this system demonstrates the accumulation of N2O, which is a marker of HNO formation, at similar rates under normoxia and anoxia. In addition, the yields of nitrite that accumulated in the absence and the presence of O2 did not differ, implying that the source of nitrite is other than autoxidation of NO. In this system metmyoglobin is instantaneously and continuously converted into compound II, leading to one-electron oxidation of SAHA to its respective transient nitroxide radical. Studies using pulse radiolysis show that one-electron oxidation of SAHA (pKa=9.56 ± 0.04) yields the respective nitroxide radical (pKa=9.1 ± 0.2), which under all experimental conditions decomposes bimolecularly to yield HNO. The proposed mechanism suggests that compound I oxidizes SAHA to the respective nitroxide radical, which decomposes bimolecularly in competition with its oxidation by compound II to form HNO. Compound II also oxidizes HNO to NO and NO to nitrite. Given that NO, but not HNO, is an efficient hypoxic cell radiosensitizer, we hypothesized that under an oxidizing environment SAHA might act as a NO donor and radiosensitize hypoxic cells. Preincubation of A549 and HT29 cells with 2.5 μM SAHA for 24h resulted in a sensitizer enhancement ratio at 0.01 survival levels (SER0.01) of 1.33 and 1.59, respectively. Preincubation of A549 cells with oxidized SAHA had hardly any effect and, with 2mM valproic acid, which lacks the hydroxamate group, resulted in SER0.01=1.17. Preincubation of HT29 cells with SAHA and Tempol, which readily oxidizes HNO to NO, enhanced the radiosensitizing effect of SAHA. Pretreatment with SAHA blocked A549 cells at the G1 stage of the cell cycle and upregulated γ-H2AX after irradiation. Overall, we conclude that SAHA enhances tumor radioresponse by multiple mechanisms that might also involve its ability to serve as a NO donor under oxidizing environments.
Collapse
Affiliation(s)
- Yuval Samuni
- IMPACT Strategic Research Centre, Deakin University School of Medicine, Geelong, VIC 3220, Australia; Department of Oral and Maxillofacial Surgery, Barzilai Medical Center, Ashkelon 78278, Israel
| | - David A Wink
- Radiation Biology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Murali C Krishna
- Radiation Biology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - James B Mitchell
- Radiation Biology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sara Goldstein
- Institute of Chemistry, The Accelerator Laboratory, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
| |
Collapse
|
14
|
Morlière P, Hug GL, Patterson LK, Mazière JC, Ausseil J, Dupas JL, Ducroix JP, Santus R, Filipe P. Chemistry of free radicals produced by oxidation of endogenous α-aminoketones. A study of 5-aminolevulinic acid and α-aminoacetone by fast kinetics spectroscopy. Biochim Biophys Acta Gen Subj 2014; 1840:3190-7. [PMID: 25018004 DOI: 10.1016/j.bbagen.2014.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 06/24/2014] [Accepted: 07/02/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND Excess 5-aminolevulinic acid (ALA) and α-aminoacetone (AA) are implicated in ketosis, porphyrinpathies and diabetes. Pathologic manifestations involve O₂⁻, H₂O₂, OH, enoyl radicals (ALA and AA) and their oxidation end products. METHODS To characterize enoyl radicals resulting from reaction of OH radicals with ALA and AA, micromolar OH concentrations were produced by pulse radiolysis of ALA and AA in aqueous solutions. RESULTS ALA and AA react with OH at k=1.5 × 10⁹ M⁻¹s⁻¹. At pH7.4, the ALA absorbance spectrum has a maximum at 330 nm (ε=750 M⁻¹cm⁻¹). This band appears as a shoulder at pH8.3 where two ALA species are present: (NH3)⁺-CH₂-CO-CH₂-CH₂-COO⁻ and NH₂-CH₂-CO-CH₂-CH₂-COO⁻ (pKa=8.3). At pH8.3, ALA reacts with oxygen (k=1.4 × 10⁸ M⁻¹s⁻¹) but not with O₂⁻. At pH8.3, AA oxidation produces two AA species characterized by an absorbance spectrum with maxima at 330 and 450 nm. ALA and AA are repaired by antioxidants (quercetin (QH), catechin, trolox, ascorbate) which are semi-oxidized (k>10(8)M⁻¹s⁻¹). QH bound to HSA or to apoferritin and ferritin repairs ALA and AA. In O₂-saturated apoferritin solutions, Q, O₂⁻, AA and reaction product(s) react with QH. CONCLUSIONS The optical absorption properties and the time evolution of ALA and AA were established for the first time. These radicals and their reaction products may be neutralized by antioxidants free in solution or bound to proteins. GENERAL SIGNIFICANCE Adjuvant antioxidant administration may be of interest in pathologies related to excess ALA or AA production.
Collapse
Affiliation(s)
- P Morlière
- INSERM, U1088, 80054 Amiens, France; CHU Amiens, Pôle Biologie, Pharmacie et Santé des Populations, Centre de Biologie Humaine, Laboratoire de Biochimie, 80054 Amiens, France; Université de Picardie Jules Verne, UFR de Pharmacie, 80036 Amiens, France.
| | - G L Hug
- University of Notre Dame, Radiation Laboratory, Notre Dame, IN 46556, USA
| | - L K Patterson
- CHU Amiens, Pôle Biologie, Pharmacie et Santé des Populations, Centre de Biologie Humaine, Laboratoire de Biochimie, 80054 Amiens, France; University of Notre Dame, Radiation Laboratory, Notre Dame, IN 46556, USA
| | - J-C Mazière
- INSERM, U1088, 80054 Amiens, France; CHU Amiens, Pôle Biologie, Pharmacie et Santé des Populations, Centre de Biologie Humaine, Laboratoire de Biochimie, 80054 Amiens, France; Université de Picardie Jules Verne, UFR de Médecine, 80036 Amiens, France
| | - J Ausseil
- INSERM, U1088, 80054 Amiens, France; CHU Amiens, Pôle Biologie, Pharmacie et Santé des Populations, Centre de Biologie Humaine, Laboratoire de Biochimie, 80054 Amiens, France; Université de Picardie Jules Verne, UFR de Médecine, 80036 Amiens, France
| | - J-L Dupas
- Université de Picardie Jules Verne, UFR de Médecine, 80036 Amiens, France; CHU Amiens, Service d'Hépato-Gastroentérologie, 80054 Amiens, France
| | - J-P Ducroix
- Université de Picardie Jules Verne, UFR de Médecine, 80036 Amiens, France; CHU Amiens, Service de Médecine Interne et Maladies Systémiques, 80054 Amiens, France
| | - R Santus
- CHU Amiens, Pôle Biologie, Pharmacie et Santé des Populations, Centre de Biologie Humaine, Laboratoire de Biochimie, 80054 Amiens, France; Muséum National d'Histoire Naturelle, Département RDDM, 75231 Paris, France
| | - P Filipe
- Hospital de Santa Maria, Faculdade de Medicina de Lisboa, Clínica Dermatologica Universitaria and Unidade de Investigação em Dermatologia, Instituto de Medicina Molecular, 1699 Lisboa Codex, Portugal
| |
Collapse
|
15
|
Das AB, Nauser T, Koppenol WH, Kettle AJ, Winterbourn CC, Nagy P. Rapid reaction of superoxide with insulin-tyrosyl radicals to generate a hydroperoxide with subsequent glutathione addition. Free Radic Biol Med 2014; 70:86-95. [PMID: 24561577 DOI: 10.1016/j.freeradbiomed.2014.02.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 01/28/2014] [Accepted: 02/05/2014] [Indexed: 10/25/2022]
Abstract
Tyrosine (Tyr) residues are major sites of radical generation during protein oxidation. We used insulin as a model to study the kinetics, mechanisms, and products of the reactions of radiation-induced or enzyme-generated protein-tyrosyl radicals with superoxide to demonstrate the feasibility of these reactions under oxidative stress conditions. We found that insulin-tyrosyl radicals combined to form dimers, mostly via the tyrosine at position 14 on the α chain (Tyr14). However, in the presence of superoxide, dimerization was largely outcompeted by the reaction of superoxide with insulin-tyrosyl radicals. Using pulse radiolysis, we measured a second-order rate constant for the latter reaction of (6±1) × 10(8) M(-1) s(-1) at pH 7.3, representing the first measured rate constant for a protein-tyrosyl radical with superoxide. Mass-spectrometry-based product analyses revealed the addition of superoxide to the insulin-Tyr14 radical to form the hydroperoxide. Glutathione efficiently reduced the hydroperoxide to the corresponding monoxide and also subsequently underwent Michael addition to the monoxide to give a diglutathionylated protein adduct. Although much slower, conjugation of the backbone amide group can form a bicyclic Tyr-monoxide derivative, allowing the addition of only one glutathione molecule. These findings suggest that Tyr-hydroperoxides should readily form on proteins under oxidative stress conditions where protein radicals and superoxide are both generated and that these should form addition products with thiol compounds such as glutathione.
Collapse
Affiliation(s)
- Andrew B Das
- Centre for Free Radical Research, Department of Pathology, University of Otago Christchurch, Christchurch 8140, New Zealand
| | - Thomas Nauser
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, 8092 Zurich, Switzerland
| | - Willem H Koppenol
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, 8092 Zurich, Switzerland
| | - Anthony J Kettle
- Centre for Free Radical Research, Department of Pathology, University of Otago Christchurch, Christchurch 8140, New Zealand
| | - Christine C Winterbourn
- Centre for Free Radical Research, Department of Pathology, University of Otago Christchurch, Christchurch 8140, New Zealand
| | - Péter Nagy
- Centre for Free Radical Research, Department of Pathology, University of Otago Christchurch, Christchurch 8140, New Zealand.
| |
Collapse
|
16
|
Cheng LL, Wang YJ, Huang DH, Yao SD, Ding GJ, Wang SL, Jiao Z. Radiolysis and photolysis studies on active transient species of berberine. Spectrochim Acta A Mol Biomol Spectrosc 2014; 124:670-676. [PMID: 24582336 DOI: 10.1016/j.saa.2014.01.085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 01/14/2014] [Accepted: 01/19/2014] [Indexed: 06/03/2023]
Abstract
In this paper, the photochemical and photobiological characters of the active radicals of berberine (BBR) was investigated for finding an efficient and safe photosensitizer with highly active transient products using in Photodynamic therapy (PDT) study. The active species of BBR was generated and identified by using pulse radiolysis method. In neutral aqueous solution, BBR react with hydrated electron and hydroxyl radical, forming the radical anion and neutral radical of BBR, and the related reaction rates were determined as 3.5×10(10) and 6.7×10(9) M(-1) s(-1), respectively. Further, the capability of BBR to photosensitize DNA cleavage was testified by laser flash photolysis (LFP) method, the results demonstrated that BBR neutral radical could react with guanine mononucleotide (K=1.9×10(9) M(-1) s(-1)) via electron transfer to give the guanine neutral radical. Additionally BBR selective cleavage single and double strand DNA at guanine moiety was observed. Finally, combining with the thermodynamic calculation, the possible photodamage mechanism of dGMP and DNA induced by BBR was clarified.
Collapse
Affiliation(s)
- Ling-Li Cheng
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Yu-Jia Wang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Da-Hong Huang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Si-De Yao
- School of Life Science and Technology, Tongji University, Shanghai 200092, China
| | - Guo-Ji Ding
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Shi-Long Wang
- School of Life Science and Technology, Tongji University, Shanghai 200092, China.
| | - Zheng Jiao
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
| |
Collapse
|
17
|
Domazou AS, Gebicka L, Didik J, Gebicki JL, van der Meijden B, Koppenol WH. The kinetics of the reaction of nitrogen dioxide with iron(II)- and iron(III) cytochrome c. Free Radic Biol Med 2014; 69:172-80. [PMID: 24447894 DOI: 10.1016/j.freeradbiomed.2014.01.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 12/13/2013] [Accepted: 01/09/2014] [Indexed: 02/05/2023]
Abstract
The reactions of NO2 with both oxidized and reduced cytochrome c at pH 7.2 and 7.4, respectively, and with N-acetyltyrosine amide and N-acetyltryptophan amide at pH 7.3 were studied by pulse radiolysis at 23 °C. NO2 oxidizes N-acetyltyrosine amide and N-acetyltryptophan amide with rate constants of (3.1±0.3)×10(5) and (1.1±0.1)×10(6) M(-1) s(-1), respectively. With iron(III)cytochrome c, the reaction involves only its amino acids, because no changes in the visible spectrum of cytochrome c are observed. The second-order rate constant is (5.8±0.7)×10(6) M(-1) s(-1) at pH 7.2. NO2 oxidizes iron(II)cytochrome c with a second-order rate constant of (6.6±0.5)×10(7) M(-1) s(-1) at pH 7.4; formation of iron(III)cytochrome c is quantitative. Based on these rate constants, we propose that the reaction with iron(II)cytochrome c proceeds via a mechanism in which 90% of NO2 oxidizes the iron center directly-most probably via reaction at the solvent-accessible heme edge-whereas 10% oxidizes the amino acid residues to the corresponding radicals, which, in turn, oxidize iron(II). Iron(II)cytochrome c is also oxidized by peroxynitrite in the presence of CO2 to iron(III)cytochrome c, with a yield of ~60% relative to peroxynitrite. Our results indicate that, in vivo, NO2 will attack preferentially the reduced form of cytochrome c; protein damage is expected to be marginal, the consequence of formation of amino acid radicals on iron(III)cytochrome c.
Collapse
Affiliation(s)
- Anastasia S Domazou
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, Zurich CH-8093, Switzerland.
| | - Lidia Gebicka
- Institute of Applied Radiation Chemistry, Faculty of Chemistry, Lodz University of Technology, 93-590 Lodz, Poland
| | - Joanna Didik
- Institute of Applied Radiation Chemistry, Faculty of Chemistry, Lodz University of Technology, 93-590 Lodz, Poland
| | - Jerzy L Gebicki
- Institute of Applied Radiation Chemistry, Faculty of Chemistry, Lodz University of Technology, 93-590 Lodz, Poland
| | - Benjamin van der Meijden
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, Zurich CH-8093, Switzerland
| | - Willem H Koppenol
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, Zurich CH-8093, Switzerland
| |
Collapse
|
18
|
Sibanda S, Parsons BJ, Houee-Levin C, Marignier JL, Paterson AWJ, Heyes DJ. One-electron oxidation and reduction of glycosaminoglycan chloramides: a kinetic study. Free Radic Biol Med 2013; 63:126-34. [PMID: 23684776 DOI: 10.1016/j.freeradbiomed.2013.05.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 04/15/2013] [Accepted: 05/08/2013] [Indexed: 12/31/2022]
Abstract
Hypochlorous acid and its acid-base counterpart, hypochlorite ions, produced under inflammatory conditions, may produce chloramides of glycosaminoglycans, these being significant components of the extracellular matrix (ECM). This may occur through the binding of myeloperoxidase directly to the glycosaminoglycans. The N-Cl group in the chloramides is a potential selective target for both reducing and oxidizing radicals, leading possibly to more efficient and damaging fragmentation of these biopolymers relative to the parent glycosaminoglycans. In this study, the fast reaction techniques of pulse radiolysis and nanosecond laser flash photolysis have been used to generate both oxidizing and reducing radicals to react with the chloramides of hyaluronan (HACl) and heparin (HepCl). The strong reducing formate radicals and hydrated electrons were found to react rapidly with both HACl and HepCl with rate constants of 1-1.7 × 10(8) and 0.7-1.2 × 10(8)M(-1)s(-1) for formate radicals and 2.2 × 10(9) and 7.2 × 10(8)M(-1)s(-1) for hydrated electrons, respectively. The spectral characteristics of the products of these reactions were identical and were consistent with initial attack at the N-Cl groups, followed by elimination of chloride ions to produce nitrogen-centered radicals, which rearrange subsequently and rapidly to produce C-2 radicals on the glucosamine moiety, supporting an earlier EPR study by M.D. Rees et al. (J. Am. Chem. Soc.125: 13719-13733; 2003). The oxidizing hydroxyl radicals also reacted rapidly with HACl and HepCl with rate constants of 2.2 × 10(8) and 1.6 × 10(8)M(-1)s(-1), with no evidence from these data for any degree of selective attack on the N-Cl group relative to the N-H groups and other sites of attack. The carbonate anion radicals were much slower with HACl and HepCl than hydroxyl radicals (1.0 × 10(5) and 8.0 × 10(4)M(-1)s(-1), respectively) but significantly faster than with the parent molecules (3.5 × 10(4) and 5.0 × 10(4)M(-1)s(-1), respectively). These findings suggest that these potential in vivo radicals may react in a site-specific manner with the N-Cl group in the glycosaminoglycan chloramides of the ECM, possibly to produce more efficient fragmentation. This is the first study therefore to conclusively demonstrate that reducing radicals react rapidly with glycosaminoglycan chloramides in a site-specific attack at the N-Cl group, probably to produce a 100% efficient biopolymer fragmentation process. Although less reactive, carbonate radicals, which may be produced in vivo via reactions of peroxynitrite with serum levels of carbon dioxide, also appear to react in a highly site-specific manner at the N-Cl group. It is not yet known if such site-specific attacks by this important in vivo species lead to a more efficient fragmentation of the biopolymers than would be expected for attack by the stronger oxidizing species, the hydroxyl radical. It is clear, however, that the N-Cl group formed under inflammatory conditions in the extracellular matrix does present a more likely target for both reactive oxygen species and reducing species than the N-H groups in the parent glycosaminoglycans.
Collapse
Affiliation(s)
- S Sibanda
- Faculty of Health and Social Sciences, Leeds Metropolitan University, Leeds LS1 3HE, UK
| | | | | | | | | | | |
Collapse
|
19
|
Sionkowska A. Flash photolysis and pulse radiolysis studies on elastin hydrolysates. J Photochem Photobiol B 2013; 125:13-8. [PMID: 23702900 DOI: 10.1016/j.jphotobiol.2013.04.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 04/24/2013] [Accepted: 04/25/2013] [Indexed: 10/26/2022]
Abstract
The formation of reactive species and free radicals in water soluble elastin hydrolysates have been investigated by pulse radiolysis and flash photolysis. Elastin hydrolysates were obtained by hydrolysis of elastin extracted from aorta. An investigation of the photochemical properties of elastin hydrolysates in water was carried out using nanosecond laser irradiation. The transient spectra of elastin hydrolysates solution excited at 266 nm showed two bands. One of them with maximum at 295 nm and the second one with maximum at 400 nm. The reactions of hydrated electrons and ˙OH radicals with elastin have been studied by pulse radiolysis. In the absorption spectra of products resulting from the reaction of elastin with e(aq)(-) small maximum absorption in UV and visible light was observed. In the absorption spectra of products resulting from the reaction of the hydroxyl radicals with elastin two bands were observed. The first one at 320 nm and the second one at 410 nm. Reaction of OH radicals with elastin hydrolysates lead to formation of Tyr phenoxyl radicals with absorption at 410 nm. The influence of the addition of sodium azide NaN3 on the formation of the transients was evaluated.
Collapse
Affiliation(s)
- Alina Sionkowska
- Faculty of Chemistry, Nicolaus Copernicus University, Torun, Poland.
| |
Collapse
|
20
|
Bisby RH, Brooke R, Navaratnam S. Effect of antioxidant oxidation potential in the oxygen radical absorption capacity (ORAC) assay. Food Chem 2007; 108:1002-7. [PMID: 26065764 DOI: 10.1016/j.foodchem.2007.12.012] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Accepted: 12/04/2007] [Indexed: 10/22/2022]
Abstract
The "oxygen radical absorption capacity" (ORAC) assay (Ou, B., Hampsch-Woodill, M., Prior, R.L. (2001). Development and validation of an improved oxygen radical absorbance capacity assay using fluorescein as the fluorescent probe. Journal of Agricultural and Food Chemistry 49, 4619-4626) is widely employed to determine antioxidant content of foods and uses fluorescein as a probe for oxidation by peroxyl radicals. Kinetic modeling of the ORAC assay suggests that the lag phase for loss of fluorescence results from equilibrium between antioxidant and fluorescein radicals and the value of the equilibrium constant determines the shape of the lag phase. For an efficient antioxidant this constitutes a "repair" reaction for fluoresceinyl radicals and produces a well defined lag phase. The lag phase becomes less marked with increasing oxidation potential of the antioxidant. Pulse radiolysis confirms that fluoresceinyl radicals are rapidly (k∼10(9)dm(3)mol(-1)s(-1)) reduced by Trolox C, a water soluble vitamin E analogue. ORAC assays of phenols with varying oxidation potentials suggest that it might be employed to obtain an estimate of the redox potential of antioxidants within food materials.
Collapse
Affiliation(s)
- Roger H Bisby
- Biomedical Sciences Research Institute, University of Salford, Salford M5 4WT, UK.
| | - Rachel Brooke
- Biomedical Sciences Research Institute, University of Salford, Salford M5 4WT, UK
| | - Suppiah Navaratnam
- Biomedical Sciences Research Institute, University of Salford, Salford M5 4WT, UK; FRRF, STFC Daresbury Laboratory, Warrington WA4 4AD, UK
| |
Collapse
|