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Jürgen Arnhold - One of the best experts on this subject based on the ideXlab platform.
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Interaction of tert-butyl hydroperoxide with Hypochlorous Acid. A spin trapping and chemiluminescence study.
Free radical research, 2002Co-Authors: A. N. Osipov, A. V. Chekanov, O. M. Panasenko, Jürgen ArnholdAbstract:The formation of radical species during the reaction of tert-butyl hydroperoxide and Hypochlorous Acid has been investigated by spin trapping and chemiluminescence. A superposition of two signals appeared incubating tert-butyl hydroperoxide with Hypochlorous Acid in the presence of the spin trap f -(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN). The first signal (aN = 1.537mT, agH = 0.148mT) was an oxidation product of POBN caused by the action of Hypochlorous Acid. The second spin adduct (aN = 1.484mT, agH = 0.233mT) was derived from a radical species that was formed in the result of reaction of tert-butyl hydroperoxide with Hypochlorous Acid. Similarly, a superposition of two signals was also obtained using the spin trap N-tert-butyl- f -phenylnitrone (PBN). tert-Butyl hydroperoxide was also treated with Fe2+ or Ce4+ in the presence of POBN. Using Fe2+ a spin adduct with a N= 1.633mT and agH = 0.276mT was observed. The major spin adduct formed with Ce4+ was characterised by αN = 1.48...
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Effects of Hypochlorous Acid on unsaturated phosphatidylcholines.
Free radical biology & medicine, 2001Co-Authors: Jürgen Arnhold, Anatolij N. Osipov, Holger Spalteholz, Jürgen SchillerAbstract:Abstract Effects of Hypochlorous Acid and of the myeloperoxidase-hydrogen peroxide-chloride system on mono- and polyunsaturated phosphatidylcholines were analyzed by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Chlorohydrins and glycols were detected as main products according to the characteristic shift of molecular masses. Mainly mono-chlorohydrins result upon the incubation of HOCl/ − OCl with 1-palmitoyl-2-oleoyl- sn -glycero-3-phosphocholine, whereas only traces of mono-glycols were detected. 1-Palmitoyl-2-linoleoyl- sn -glycero-3-phosphocholine yielded a complex mixture of products. Mono-chlorohydrins and glycols dominated only at short incubation, while bis-chlorohydrins as well as products containing one chlorohydrin and one glycol moiety appeared after longer incubation. Similarly, a complex product mixture resulted upon incubation of 1-stearoyl-2-arachidonoyl- sn -glycero-3-phosphocholine with Hypochlorous Acid. Additionally, tris-chlorohydrins, products with two chlorohydrin and one glycol moiety, as well as lysophosphatidylcholines and fragmentation products of the arachidonoyl side chain were detectable. Mono-chlorohydrins of 1-stearoyl-2-oleoyl- sn -glycero-3-phosphocholine were detected after the incubation of the latter phospholipid with the myeloperoxidase-hydrogen peroxide-chloride system at pH 6.0. These chlorohydrins were not observed in the absence of chloride, hydrogen peroxide, or myeloperoxidase as well as in the presence of methionine, taurine, or sodium azide. Thus, mono-chlorohydrins in 1-stearoyl-2-oleoyl- sn -glycero-3-phosphocholine produced by Hypochlorous Acid from the myeloperoxidase-hydrogen peroxide-chloride system can also be detected by means of MALDI-TOF MS.
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Reactions of pholasin with peroxidases and Hypochlorous Acid.
Free radical biology & medicine, 2000Co-Authors: Sabine Reichl, Jürgen Arnhold, Jürgen Schiller, Jan Knight, Klaus ArnoldAbstract:Abstract The ability of myeloperoxidase (MPO) and horseradish peroxidase (HRP) to induce chemiluminescence (CL) in Pholasin (Knight Scientific, Plymouth, UK), the photoprotein of the Common Piddock Pholas dactylus , was studied. The oxidation of Pholasin by compound I or II of HRP induced an intense light emission, whereas native HRP showed only a small effect. The luminescence observed upon incubation of Pholasin with native MPO was diminished by preincubation with catalase. Considering the high instability of diluted MPO, it is concluded that traces of hydrogen peroxide in water converted MPO to its active forms, compound I and/or II, which are able to oxidize Pholasin. Indeed, the addition of hydrogen peroxide to a mixture of MPO and Pholasin induced an intense burst of light. This emission was enhanced in degree and duration in the absence of chloride. Hypochlorous Acid, the reaction product of Cl − and compound I of MPO, was itself able to elicit a luminescent response in Pholasin and this luminescence was strongly inhibited by methionine and taurine. However, both of these HOCl scavengers only slightly reduced the light emission induced by MPO/H 2 O 2 in both the presence or absence of chloride. Thus, Hypochlorous Acid produced by the MPO/H 2 O 2 /Cl − system, under the conditions described in this study, did not contribute to Pholasin luminescence. The Pholasin luminescence elicited by formyl-leucyl-methionyl-phenylalanine (fMLP)-stimulated neutrophils depends both on superoxide anion radicals and higher oxidation states of myeloperoxidase (but not on Hypochlorous Acid). This is shown by the inhibition of luminescence with superoxide dismutase and potassium cyanide, together with the lack of effect of both methionine and taurine. The luminescence response is about eight times greater in cells stimulated with fMLP/cytochalasin B than with fMLP alone.
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REACTION OF Hypochlorous Acid WITH HYDROGEN PEROXIDE AND TERT-BUTYL HYDROPEROXIDE. 1H NMR SPECTROSCOPY AND CHEMILUMINESCENCE ANALYSES
Zeitschrift für Naturforschung C, 1996Co-Authors: Jürgen Arnhold, O. M. Panasenko, Jürgen Schiller, Klaus Arnold, Vladimirov Yurij A, Sergienko ValerijAbstract:Abstract In contrast to the well-known reaction of Hypochlorous Acid with hydrogen peroxide, no singlet oxygen is formed as the result of reaction between Hypochlorous Acid and tert -butyl hydroperoxide. The reaction with hydrogen peroxide yielded a quadratic dependence of light intensity on reactant concentration, a drastic enhancement of luminescence yield using D2O as solvent and only an emission of red light, that are typical characteristics of emission resulting from two molecules of delta singlet oxygen. Other chemiluminescence properties were observed using tert-butyl hydroperoxide. There was a linear dependence of light intensity on reactant concentration using rm-butyl hydroperoxide in excess with a decline of emission at higher concentrations. 1H-NMR spectroscopic analysis revealed di-tert-butyl peroxide, tert -butanol and also tert-butyl hypochlorite, acetone and acetate as products of the reaction between Hypochlorous Acid and tert -butyl hydroperoxide. The formation of di-tert-butyl peroxide is only possible assuming a tert-butyloxy radical as primary intermediate product of this reaction. Our results demonstrate that alkoxy radicals derived from organic hydroperoxides can participate in lipid peroxidation induced by Hypochlorous Acid. On the other hand, singlet oxygen did not influence the yield of peroxidation products. Changing H2O for D2O in suspension of egg yolk phosphaditylcholine no differences in accumulation of thiobarbituric Acid reactive products were observed.
Jürgen Schiller - One of the best experts on this subject based on the ideXlab platform.
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Formation of lysophospholipids from unsaturated phosphatidylcholines under the influence of Hypochlorous Acid
Biochimica et biophysica acta, 2002Co-Authors: Juergen Arnhold, A. N. Osipov, Holger Spalteholz, Oleg M Panasenko, Jürgen SchillerAbstract:The formation of lysophosphatidylcholines from unsaturated phosphatidylcholines upon treatment with Hypochlorous Acid was evaluated by means of MALDI-TOF mass spectrometry and 31P NMR spectroscopy. With an increasing number of double bonds in a fatty Acid residue, the yield of lysophosphatidylcholines with a saturated fatty Acid residue increased considerably in comparison to the total amount of higher molecular weight products like chlorohydrins and glycols. High amounts of lysophosphatidylcholines were formed from phospholipids containing arachidonic or docosahexaenoic Acid residues. In phospholipids with monounsaturated fatty Acid residues, the position of the double bond did not influence the yield of lyso-products. Besides the exclusive formation of chlorohydrin and glycol, Hypochlorous Acid caused the cleavage of the unsaturated fatty Acid residue independent of its location at the first or second position of the glycerol backbone. In contrast, strong alkaline conditions, i.e. saponification led also to a hydrolysis of the saturated fatty Acid residue from phosphatidylcholines. It is concluded that both MALDI-TOF mass spectrometry and 31P NMR spectroscopy are able to detect the formation of lysophosphatidylcholines. We conclude also that the formation of lysophospholipids from unsaturated phosphatidylcholines by Hypochlorous Acid can be relevant in vivo under acute inflammatory conditions.
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Effects of Hypochlorous Acid on unsaturated phosphatidylcholines.
Free radical biology & medicine, 2001Co-Authors: Jürgen Arnhold, Anatolij N. Osipov, Holger Spalteholz, Jürgen SchillerAbstract:Abstract Effects of Hypochlorous Acid and of the myeloperoxidase-hydrogen peroxide-chloride system on mono- and polyunsaturated phosphatidylcholines were analyzed by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Chlorohydrins and glycols were detected as main products according to the characteristic shift of molecular masses. Mainly mono-chlorohydrins result upon the incubation of HOCl/ − OCl with 1-palmitoyl-2-oleoyl- sn -glycero-3-phosphocholine, whereas only traces of mono-glycols were detected. 1-Palmitoyl-2-linoleoyl- sn -glycero-3-phosphocholine yielded a complex mixture of products. Mono-chlorohydrins and glycols dominated only at short incubation, while bis-chlorohydrins as well as products containing one chlorohydrin and one glycol moiety appeared after longer incubation. Similarly, a complex product mixture resulted upon incubation of 1-stearoyl-2-arachidonoyl- sn -glycero-3-phosphocholine with Hypochlorous Acid. Additionally, tris-chlorohydrins, products with two chlorohydrin and one glycol moiety, as well as lysophosphatidylcholines and fragmentation products of the arachidonoyl side chain were detectable. Mono-chlorohydrins of 1-stearoyl-2-oleoyl- sn -glycero-3-phosphocholine were detected after the incubation of the latter phospholipid with the myeloperoxidase-hydrogen peroxide-chloride system at pH 6.0. These chlorohydrins were not observed in the absence of chloride, hydrogen peroxide, or myeloperoxidase as well as in the presence of methionine, taurine, or sodium azide. Thus, mono-chlorohydrins in 1-stearoyl-2-oleoyl- sn -glycero-3-phosphocholine produced by Hypochlorous Acid from the myeloperoxidase-hydrogen peroxide-chloride system can also be detected by means of MALDI-TOF MS.
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Reactions of pholasin with peroxidases and Hypochlorous Acid.
Free radical biology & medicine, 2000Co-Authors: Sabine Reichl, Jürgen Arnhold, Jürgen Schiller, Jan Knight, Klaus ArnoldAbstract:Abstract The ability of myeloperoxidase (MPO) and horseradish peroxidase (HRP) to induce chemiluminescence (CL) in Pholasin (Knight Scientific, Plymouth, UK), the photoprotein of the Common Piddock Pholas dactylus , was studied. The oxidation of Pholasin by compound I or II of HRP induced an intense light emission, whereas native HRP showed only a small effect. The luminescence observed upon incubation of Pholasin with native MPO was diminished by preincubation with catalase. Considering the high instability of diluted MPO, it is concluded that traces of hydrogen peroxide in water converted MPO to its active forms, compound I and/or II, which are able to oxidize Pholasin. Indeed, the addition of hydrogen peroxide to a mixture of MPO and Pholasin induced an intense burst of light. This emission was enhanced in degree and duration in the absence of chloride. Hypochlorous Acid, the reaction product of Cl − and compound I of MPO, was itself able to elicit a luminescent response in Pholasin and this luminescence was strongly inhibited by methionine and taurine. However, both of these HOCl scavengers only slightly reduced the light emission induced by MPO/H 2 O 2 in both the presence or absence of chloride. Thus, Hypochlorous Acid produced by the MPO/H 2 O 2 /Cl − system, under the conditions described in this study, did not contribute to Pholasin luminescence. The Pholasin luminescence elicited by formyl-leucyl-methionyl-phenylalanine (fMLP)-stimulated neutrophils depends both on superoxide anion radicals and higher oxidation states of myeloperoxidase (but not on Hypochlorous Acid). This is shown by the inhibition of luminescence with superoxide dismutase and potassium cyanide, together with the lack of effect of both methionine and taurine. The luminescence response is about eight times greater in cells stimulated with fMLP/cytochalasin B than with fMLP alone.
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REACTION OF Hypochlorous Acid WITH HYDROGEN PEROXIDE AND TERT-BUTYL HYDROPEROXIDE. 1H NMR SPECTROSCOPY AND CHEMILUMINESCENCE ANALYSES
Zeitschrift für Naturforschung C, 1996Co-Authors: Jürgen Arnhold, O. M. Panasenko, Jürgen Schiller, Klaus Arnold, Vladimirov Yurij A, Sergienko ValerijAbstract:Abstract In contrast to the well-known reaction of Hypochlorous Acid with hydrogen peroxide, no singlet oxygen is formed as the result of reaction between Hypochlorous Acid and tert -butyl hydroperoxide. The reaction with hydrogen peroxide yielded a quadratic dependence of light intensity on reactant concentration, a drastic enhancement of luminescence yield using D2O as solvent and only an emission of red light, that are typical characteristics of emission resulting from two molecules of delta singlet oxygen. Other chemiluminescence properties were observed using tert-butyl hydroperoxide. There was a linear dependence of light intensity on reactant concentration using rm-butyl hydroperoxide in excess with a decline of emission at higher concentrations. 1H-NMR spectroscopic analysis revealed di-tert-butyl peroxide, tert -butanol and also tert-butyl hypochlorite, acetone and acetate as products of the reaction between Hypochlorous Acid and tert -butyl hydroperoxide. The formation of di-tert-butyl peroxide is only possible assuming a tert-butyloxy radical as primary intermediate product of this reaction. Our results demonstrate that alkoxy radicals derived from organic hydroperoxides can participate in lipid peroxidation induced by Hypochlorous Acid. On the other hand, singlet oxygen did not influence the yield of peroxidation products. Changing H2O for D2O in suspension of egg yolk phosphaditylcholine no differences in accumulation of thiobarbituric Acid reactive products were observed.
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Peroxidation of egg yolk phosphatidylcholine liposomes by Hypochlorous Acid
Biochimica et biophysica acta, 1994Co-Authors: O. M. Panasenko, Jürgen Schiller, Klaus Arnold, J. Amhold, V.i. SergienkoAbstract:Abstract The powerful neutrophil-derived oxidant Hypochlorous Acid HOCl/OCl− is assumed to contribute to tissue injury m a number of pathological states accompanied by massive accumulation of neutrophils. The production of malondialdehyde to indicate lipid peroxidation was studied in egg yolk phosphatidylcholine liposomes upon treatment with NaOCl as a source for Hypochlorous Acid. Its accumulation was inhibited by a-tocopherol and butylated hydroxytoluene. Singlet oxygen, hydroxyl radicals or Superoxide anion radicals derived from direct reactions of Hypochlorous Acid seem not to be involved in initiation of lipid peroxidation because the malondialdehyde accumulation was unaffected by hydrogen peroxide, catalase, Superoxide dismutase, ferrous sulphate or ferric chloride. Double bonds of fatty Acid residues seem to be the primary target for NaOCl. Their number is continuously diminished in liposomes (2 mg lipids/ml) after incubation with increasing amounts of NaOCl at 37°C for 40 min as detected by two independent methods (iodine bromide reduction and 1H-NMR spectroscopy). A 1:1 molar ratio between the loss of double bonds and NaOCl added was found only at low NaOCl concentrations. Then double bonds are decreased with a lower efficiency. A continuous increase of lipid peroxidation products was only observed up to 0.5–0.7 mmol/1 NaOCl. The yield of lipid hydroperoxides kept constant at higher NaOCl concentrations. However, diene conjugates and malondialdehyde exhibit a maximum at 0.7–1 mmol/1 or 0.5 mmol/1 NaOCl, respectively, while the concentration of these products decreases at higher doses of NaOCl. The decrease of malondialdehyde was more pronounced than for diene conjugates. These results were discussed from the background that at minimum two (diene conjugates) or three (malondialdehyde) double bonds in a fatty Acid residue are necessary for formation of lipid peroxidation products.
Yufen Zhao - One of the best experts on this subject based on the ideXlab platform.
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a fluorescein based turn on fluorescence probe for Hypochlorous Acid detection and its application in cell imaging
Sensors and Actuators B-chemical, 2018Co-Authors: Xiaopeng Yang, Yufen Zhao, Di Zhang, Yongxiang Liu, Jun TangAbstract:Abstract A simple fluorescent probe F-BH was designed and synthesized, introducing C N group which can be a recognition site for Hypochlorous Acid into the fluorescent probe molecule by using 2-benzothiazole hydrazone and formylated fluorescein. The fluorescence intensity of the probe F-BH solution was very weak, while the fluorescence of the solution was obviously enhanced and the color of the solution changed after the addition of ClO− ion. The selection and competition experiments proved that the probe has great selectivity for recognition of Hypochlorous Acid over other ROSs/RNSs and anions. Fluorescence titration experiments show that the probe has a low detection limit (17.5 nM). The probe has been successfully applied to real-time detection of Hypochlorous Acid in Hela cells.
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A fluorescein-based “turn-on” fluorescence probe for Hypochlorous Acid detection and its application in cell imaging
Sensors and Actuators B: Chemical, 2018Co-Authors: Xiaopeng Yang, Di Zhang, Yongxiang Liu, Jun Tang, Yufen ZhaoAbstract:Abstract A simple fluorescent probe F-BH was designed and synthesized, introducing C N group which can be a recognition site for Hypochlorous Acid into the fluorescent probe molecule by using 2-benzothiazole hydrazone and formylated fluorescein. The fluorescence intensity of the probe F-BH solution was very weak, while the fluorescence of the solution was obviously enhanced and the color of the solution changed after the addition of ClO− ion. The selection and competition experiments proved that the probe has great selectivity for recognition of Hypochlorous Acid over other ROSs/RNSs and anions. Fluorescence titration experiments show that the probe has a low detection limit (17.5 nM). The probe has been successfully applied to real-time detection of Hypochlorous Acid in Hela cells.
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Lysosomal-Targeted Two-Photon Fluorescent Probe to Sense Hypochlorous Acid in Live Cells
Analytical chemistry, 2017Co-Authors: Beibei Zhang, Xiaopeng Yang, Rui Zhang, Yao Liu, Xueling Ren, Ming Xian, Yufen ZhaoAbstract:A two-photon reversible fluorescent probe L1 was designed and synthesized. The fluorescence intensity of the probe solution was strong, while the fluorescence of the solution was obviously quenched and the color of the solution was changed after the addition of Hypochlorous Acid, indicating this is “naked-eye sensor” for the detection of HClO. The probe showed great selectivity for Hypochlorous Acid over other reactive oxygen species (ROS) and anions. Fluorescence titration experiments showed that the probe has a low detection limit of 0.674 μM. Because of a morpholine group introduced to the naphathalimide framework, probe L1 was successfully applied to detect intracellular HClO in lysosome.
A. N. Osipov - One of the best experts on this subject based on the ideXlab platform.
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Formation of lysophospholipids from unsaturated phosphatidylcholines under the influence of Hypochlorous Acid
Biochimica et biophysica acta, 2002Co-Authors: Juergen Arnhold, A. N. Osipov, Holger Spalteholz, Oleg M Panasenko, Jürgen SchillerAbstract:The formation of lysophosphatidylcholines from unsaturated phosphatidylcholines upon treatment with Hypochlorous Acid was evaluated by means of MALDI-TOF mass spectrometry and 31P NMR spectroscopy. With an increasing number of double bonds in a fatty Acid residue, the yield of lysophosphatidylcholines with a saturated fatty Acid residue increased considerably in comparison to the total amount of higher molecular weight products like chlorohydrins and glycols. High amounts of lysophosphatidylcholines were formed from phospholipids containing arachidonic or docosahexaenoic Acid residues. In phospholipids with monounsaturated fatty Acid residues, the position of the double bond did not influence the yield of lyso-products. Besides the exclusive formation of chlorohydrin and glycol, Hypochlorous Acid caused the cleavage of the unsaturated fatty Acid residue independent of its location at the first or second position of the glycerol backbone. In contrast, strong alkaline conditions, i.e. saponification led also to a hydrolysis of the saturated fatty Acid residue from phosphatidylcholines. It is concluded that both MALDI-TOF mass spectrometry and 31P NMR spectroscopy are able to detect the formation of lysophosphatidylcholines. We conclude also that the formation of lysophospholipids from unsaturated phosphatidylcholines by Hypochlorous Acid can be relevant in vivo under acute inflammatory conditions.
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Interaction of tert-butyl hydroperoxide with Hypochlorous Acid. A spin trapping and chemiluminescence study.
Free radical research, 2002Co-Authors: A. N. Osipov, A. V. Chekanov, O. M. Panasenko, Jürgen ArnholdAbstract:The formation of radical species during the reaction of tert-butyl hydroperoxide and Hypochlorous Acid has been investigated by spin trapping and chemiluminescence. A superposition of two signals appeared incubating tert-butyl hydroperoxide with Hypochlorous Acid in the presence of the spin trap f -(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN). The first signal (aN = 1.537mT, agH = 0.148mT) was an oxidation product of POBN caused by the action of Hypochlorous Acid. The second spin adduct (aN = 1.484mT, agH = 0.233mT) was derived from a radical species that was formed in the result of reaction of tert-butyl hydroperoxide with Hypochlorous Acid. Similarly, a superposition of two signals was also obtained using the spin trap N-tert-butyl- f -phenylnitrone (PBN). tert-Butyl hydroperoxide was also treated with Fe2+ or Ce4+ in the presence of POBN. Using Fe2+ a spin adduct with a N= 1.633mT and agH = 0.276mT was observed. The major spin adduct formed with Ce4+ was characterised by αN = 1.48...
O. M. Panasenko - One of the best experts on this subject based on the ideXlab platform.
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Interaction of tert-butyl hydroperoxide with Hypochlorous Acid. A spin trapping and chemiluminescence study.
Free radical research, 2002Co-Authors: A. N. Osipov, A. V. Chekanov, O. M. Panasenko, Jürgen ArnholdAbstract:The formation of radical species during the reaction of tert-butyl hydroperoxide and Hypochlorous Acid has been investigated by spin trapping and chemiluminescence. A superposition of two signals appeared incubating tert-butyl hydroperoxide with Hypochlorous Acid in the presence of the spin trap f -(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN). The first signal (aN = 1.537mT, agH = 0.148mT) was an oxidation product of POBN caused by the action of Hypochlorous Acid. The second spin adduct (aN = 1.484mT, agH = 0.233mT) was derived from a radical species that was formed in the result of reaction of tert-butyl hydroperoxide with Hypochlorous Acid. Similarly, a superposition of two signals was also obtained using the spin trap N-tert-butyl- f -phenylnitrone (PBN). tert-Butyl hydroperoxide was also treated with Fe2+ or Ce4+ in the presence of POBN. Using Fe2+ a spin adduct with a N= 1.633mT and agH = 0.276mT was observed. The major spin adduct formed with Ce4+ was characterised by αN = 1.48...
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REACTION OF Hypochlorous Acid WITH HYDROGEN PEROXIDE AND TERT-BUTYL HYDROPEROXIDE. 1H NMR SPECTROSCOPY AND CHEMILUMINESCENCE ANALYSES
Zeitschrift für Naturforschung C, 1996Co-Authors: Jürgen Arnhold, O. M. Panasenko, Jürgen Schiller, Klaus Arnold, Vladimirov Yurij A, Sergienko ValerijAbstract:Abstract In contrast to the well-known reaction of Hypochlorous Acid with hydrogen peroxide, no singlet oxygen is formed as the result of reaction between Hypochlorous Acid and tert -butyl hydroperoxide. The reaction with hydrogen peroxide yielded a quadratic dependence of light intensity on reactant concentration, a drastic enhancement of luminescence yield using D2O as solvent and only an emission of red light, that are typical characteristics of emission resulting from two molecules of delta singlet oxygen. Other chemiluminescence properties were observed using tert-butyl hydroperoxide. There was a linear dependence of light intensity on reactant concentration using rm-butyl hydroperoxide in excess with a decline of emission at higher concentrations. 1H-NMR spectroscopic analysis revealed di-tert-butyl peroxide, tert -butanol and also tert-butyl hypochlorite, acetone and acetate as products of the reaction between Hypochlorous Acid and tert -butyl hydroperoxide. The formation of di-tert-butyl peroxide is only possible assuming a tert-butyloxy radical as primary intermediate product of this reaction. Our results demonstrate that alkoxy radicals derived from organic hydroperoxides can participate in lipid peroxidation induced by Hypochlorous Acid. On the other hand, singlet oxygen did not influence the yield of peroxidation products. Changing H2O for D2O in suspension of egg yolk phosphaditylcholine no differences in accumulation of thiobarbituric Acid reactive products were observed.
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Peroxidation of egg yolk phosphatidylcholine liposomes by Hypochlorous Acid
Biochimica et biophysica acta, 1994Co-Authors: O. M. Panasenko, Jürgen Schiller, Klaus Arnold, J. Amhold, V.i. SergienkoAbstract:Abstract The powerful neutrophil-derived oxidant Hypochlorous Acid HOCl/OCl− is assumed to contribute to tissue injury m a number of pathological states accompanied by massive accumulation of neutrophils. The production of malondialdehyde to indicate lipid peroxidation was studied in egg yolk phosphatidylcholine liposomes upon treatment with NaOCl as a source for Hypochlorous Acid. Its accumulation was inhibited by a-tocopherol and butylated hydroxytoluene. Singlet oxygen, hydroxyl radicals or Superoxide anion radicals derived from direct reactions of Hypochlorous Acid seem not to be involved in initiation of lipid peroxidation because the malondialdehyde accumulation was unaffected by hydrogen peroxide, catalase, Superoxide dismutase, ferrous sulphate or ferric chloride. Double bonds of fatty Acid residues seem to be the primary target for NaOCl. Their number is continuously diminished in liposomes (2 mg lipids/ml) after incubation with increasing amounts of NaOCl at 37°C for 40 min as detected by two independent methods (iodine bromide reduction and 1H-NMR spectroscopy). A 1:1 molar ratio between the loss of double bonds and NaOCl added was found only at low NaOCl concentrations. Then double bonds are decreased with a lower efficiency. A continuous increase of lipid peroxidation products was only observed up to 0.5–0.7 mmol/1 NaOCl. The yield of lipid hydroperoxides kept constant at higher NaOCl concentrations. However, diene conjugates and malondialdehyde exhibit a maximum at 0.7–1 mmol/1 or 0.5 mmol/1 NaOCl, respectively, while the concentration of these products decreases at higher doses of NaOCl. The decrease of malondialdehyde was more pronounced than for diene conjugates. These results were discussed from the background that at minimum two (diene conjugates) or three (malondialdehyde) double bonds in a fatty Acid residue are necessary for formation of lipid peroxidation products.