碳酸氢盐催化的半胱氨酸和相关的硫醇的过氧化氢氧化
Bicarbonate-catalyzed hydrogen peroxide oxidation of cysteine and related thiols
摘要
研究了碳酸氢盐对半胱氨酸，谷胱甘肽和N-乙酰半胱氨酸的H2O2氧化速率对相应二硫化物的影响。
不同硫醇的pH8的相对氧化速率与硫醇基团的pKa值成反比，反应性亲核试剂被鉴定为硫醇盐阴离子或其动力学等价物。
对于所有三种底物，硫醇盐阴离子与过氧化氢反应在25℃下的二级速率常数为17±2M-1s-1。
在碳酸氢盐（> 25 mM）存在下，观察到的硫醇盐氧化速率提高了两倍或更多，并且提出催化作用与过氧化氢与碳酸氢盐的平衡反应形成过氧一碳酸酯（peroxymonocarbonate）有关（通过二氧化碳）。
计算出的三种硫醇盐阴离子与过氧一碳酸酯直接反应的二级速率常数落在900-2000M-1s-1的范围内。
通过过氧一碳酸酯进一步氧化二硫化物导致硫代磺酸盐和磺酸盐产物的形成。这些结果有力地表明，过氧一碳酸酯（peroxymonocarbonate）应被视为有氧代谢中的活性氧物种，与硫醇氧化有关。
图形概要
研究了碳酸氢盐对半胱氨酸，谷胱甘肽和N-乙酰半胱氨酸的H2O2氧化速率对相应二硫化物的影响。碳酸氢盐催化与过氧一碳酸酯的形成有关（通过与CO 2的过氧化物反应）。三种硫醇盐阴离子与过氧一碳酸酯反应的计算二级速率常数为900-2000M-1s-1。
关键词
活性氧 过氧单碳酸酯 过氧碳酸酯半胱氨酸 谷胱甘肽 N-乙酰半胱氨酸 过氧化氢硫醇 氧化 氧化应激碳酸氢盐硫醇自由基 二硫化物氧化 硫代磺酸盐 磺酸 线粒体通透性转换
Bicarbonate-catalyzed hydrogen peroxide oxidation of cysteine and related thiols
Abstract
The effect of bicarbonate on the rates of the H2O2 oxidation of cysteine, gluthathione, and N-acetylcysteine to the corresponding disulfides was investigated.
The relative oxidation rates at pH 8 for the different thiols are inversely related to the pKa values of the thiol groups, and the reactive nucleophiles are identified as the thiolate anions or their kinetic equivalents.
The second-order rate constants at 25 °C for the reaction of the thiolate anions with hydrogen peroxide are 17 ± 2 M−1 s−1 for all three substrates.
In the presence of bicarbonate (>25 mM), the observed rate of thiolate oxidation is increased by a factor of two or more, and the catalysis is proposed to be associated with the formation of peroxymonocarbonate from the equilibrium reaction of hydrogen peroxide with bicarbonate (via CO2).
The calculated second-order rate constants for the direct reaction of the three thiolate anions with peroxymonocarbonate fall within the range of 900–2000 M−1 s−1.
Further oxidation of disulfides by peroxymonocarbonate results in the formation of thiosulfonate and sulfonate products. These results strongly suggest that peroxymonocarbonate should be considered as a reactive oxygen species in aerobic metabolism with relevance in thiol oxidations.
Graphical abstract
The effect of bicarbonate on the rates of the H2O2 oxidation of cysteine, gluthathione, and N-acetylcysteine to the corresponding disulfides was investigated. Bicarbonate catalysis is associated with the formation of peroxymonocarbonate (via peroxide reaction with CO2). Calculated second-order rate constants for the reaction of the three thiolate anions with peroxymonocarbonate are 900–2000 M−1 s−1.
Keywords
Reactive oxygen species Peroxymonocarbonate Peroxycarbonate CysteineGluthathione N-acetylcysteine Hydrogen peroxideThiol oxidation Oxidative stress Bicarbonate Thiols Free radicals Disulfide oxidation Thiosulfonate Sulfonic acid Mitochondrial permeability transition
Author links open overlay panel Celeste Aida S.Regino1 David E.Richardson
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https://doi.org/10.1016/j.ica.2007.05.020Get rights and content
Bicarbonate-catalyzed hydrogen peroxide oxidation of cysteine and related thiols - ScienceDirect https://www.sciencedirect.com/science/article/pii/S0020169307003234
碳酸氢盐诱导的H2O2活化用于无金属氧化脱硫
Bicarbonate-induced activation of H2O2 for metal-free oxidative desulfurization
强调
•在室温下实现高效的无金属氧化脱硫。
•H2O2的碳酸氢盐活化产生原位过氧一碳酸酯氧化剂。
•均相和多相催化剂都表现出有效的高效氧化脱硫（ODS）活性。
•使用廉价和环保的化学品，如碳酸氢钠和水。
摘要
含有二苯并噻吩（DBT）和芳族噻吩衍生物的模型油的高效氧化脱硫（ODS）已在室温下使用无机碳酸氢盐（HCO3-）的过氧化氢活化实现。
使用原位形成过氧一碳酸酯作为氧化剂，主要模型底物DBT向相应的DBT-砜的转化在双相反应条件下容易完成。在水 - 乙腈极性相的存在下，将水含量增加至50％使提取能力降低3倍以上，但仍实现~90％的DBT氧化。在重复的ODS循环期间保持碳酸氢盐催化剂的氧化能力，但DBT去除效率关键取决于极性相的提取能力。在非均相反应条件下，与均相催化体系相比，碳酸氢盐改性的离子交换树脂实现了类似的ODS活性。另外，在碱性条件下使用气态CO 2前体有效形成过氧一碳酸酯也用于DBT氧化。
本研究提出NaHCO3 / H2O2催化体系是一种有效且廉价的无金属替代物，用于从燃料油中氧化除去芳香硫化合物。
Bicarbonate-induced activation of H2O2 for metal-free oxidative desulfurization
Highlights
• Efficient metal-free oxidative desulfurization is achieved at room temperature.
• Bicarbonate activation of H2O2 generates in-situ peroxymonocarbonate oxidant.
• Both homogenous and heterogenized catalysts exhibit efficient ODS activity.
• Use of cheap and eco-friendly chemicals like sodium bicarbonate and water.
Abstract
Efficient oxidative desulfurization (ODS) of model oil containing dibenzothiophene (DBT) and aromatic thiophenic derivatives has been achieved at room temperature using hydrogen peroxide activation by inorganic bicarbonate (HCO3−). Using in-situ formation of peroxymonocarbonate as oxidant, the transformation of main model substrate DBT to corresponding DBT-sulfone was easily accomplished in biphasic reaction conditions. In the presence of water–acetonitrile polar phase, increasing the water content upto 50% decreased the extraction capacity more than 3 times, but ∼90% DBT oxidation was still achieved. The oxidizing capacity of bicarbonate catalyst was maintained during repeated ODS cycles, but DBT removal efficiency was critically dependent on the extraction capacity of the polar phase.
Under heterogeneous reaction conditions, bicarbonate-modified ion-exchange resin achieved similar ODS activity compared to the homogeneous catalytic system.
Additionally, the efficient formation of peroxymonocarbonate using gaseous CO2 precursor in alkaline conditions was also utilized for DBT oxidation. The present study proposes the NaHCO3/H2O2 catalytic system as an efficient and cheap metal-free alternative for the oxidative removal of aromatic sulfur compounds from fuel oil.
Keywords
Oxidative desulfurization (ODS)Hydrogen peroxideBicarbonateDibenzothiopheneIon-exchange resin
Author links open overlay panelAlok D.BokareWonyongChoi
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https://doi.org/10.1016/j.jhazmat.2015.10.063Get rights and content
Bicarbonate-induced activation of H2O2 for metal-free oxidative desulfurization - ScienceDirect https://www.sciencedirect.com/science/article/pii/S0304389415301916
过氧化氢碳酸氢盐活化的平衡，动力学和机理：过氧化碳酸氢盐氧化硫化物
Equilibria, Kinetics, and Mechanism in the Bicarbonate Activation of Hydrogen Peroxide: Oxidation of Sulfides by Peroxymonocarbonate
抽象
碳酸氢根离子是过氧化氢氧化硫化物的有效活化剂。动力学和光谱学结果支持在催化反应中形成过氧一碳酸根离子（HCO4-）作为氧化剂。
过氧化氢和碳酸氢盐形成HCO4-的反应在25℃（t1 /2≈300s）下在中性pH下在水溶液和醇/水混合物中快速发生，并且13C NMR对反应的平衡分析导致估计HCO4- / HCO3-对的电极电位（1.8V对NHE）。
通过使用NH 4 HCO 3而不是通过使用第1组盐来增强碳酸氢盐催化剂的溶解度，第1组盐在混合溶剂中倾向于具有较低的溶解度并且可以导致相分离。提出了乙基苯硫醚和相关硫化物氧化的速率定律和机理分析。
HCO4-的硫化物氧化的二级速率常数比H2O2的二级速率常数大约300倍，并且这种增加与基于布朗斯台德分析其他异分解过氧化物氧化的动力学的预期一致。
在高浓度的H 2 O 2中，H 2 O 2中的二级路径是显着的，并且该路径被解释为伴随HCO 4 - 的亲电子氧的衬底攻击的碳酸盐置换的H 2 O 2的一般酸催化。
在溶剂中增加高达80％的水含量会增加氧化速率。
BAP（碳酸氢盐活化的过氧化物）氧化系统是一种简单，廉价且相对无毒的其他氧化剂和过氧酸的替代品，并且它可以用于需要温和的中性pH氧化剂的各种氧化物中。碳酸氢盐源和共溶剂的变化可以允许优化底物溶解度和氧化速率，用于诸如有机合成和化学战剂去污的应用。
Equilibria, Kinetics, and Mechanism in the Bicarbonate Activation of Hydrogen Peroxide: Oxidation of Sulfides by Peroxymonocarbonate
Abstract
Bicarbonate ion is an effective activator for hydrogen peroxide in the oxidation of sulfides. Kinetic and spectroscopic results support the formation of peroxymonocarbonate ion (HCO4-) as the oxidant in the catalytic reactions. The reaction of hydrogen peroxide and bicarbonate to form HCO4- occurs rapidly at 25 °C (t1/2 ≈ 300 s) near neutral pH in aqueous solution and alcohol/water mixtures, and an equilibrium analysis of the reaction by 13C NMR leads to an estimate of the electrode potential for the HCO4-/HCO3- couple (1.8 V vs NHE). Solubility of the bicarbonate catalyst is enhanced by the use of NH4HCO3 rather than by the use of group 1 salts, which tend to have lower solubility in the mixed solvents and can lead to phase separation. Rate laws and mechanistic analyses are presented for the oxidation of ethylphenylsulfide and related sulfides. The second-order rate constants for sulfide oxidations by HCO4- are ∼300-fold greater than those for H2O2, and this increase is consistent with expectations based on a Brønsted analysis of the kinetics for other heterolytic peroxide oxidations. At high concentrations of H2O2, a pathway that is second order in H2O2 is significant, and this path is interpreted as a general acid catalysis by H2O2 of carbonate displacement accompanying substrate attack at the electrophilic oxygen of HCO4-. Increasing water content up to 80% in the solvent increases the rate of oxidation. The BAP (bicarbonate-activated peroxide) oxidation system is a simple, inexpensive, and relatively nontoxic alternative to other oxidants and peroxyacids, and it can be used in a variety of oxidations where a mild, neutral pH oxidant is required. Variation of bicarbonate source and the cosolvent can allow optimization of substrate solubility and oxidation rates for applications such as organic synthesis and chemical warfare agent decontamination.
David E. Richardson*, Huirong Yao, Karen M. Frank‡, and Deon A. Bennett
Contribution from the Center for Catalysis, Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200
J. Am. Chem. Soc., 2000, 122 (8), pp 1729–1739
DOI: 10.1021/ja9927467
Publication Date (Web): February 10, 2000
Copyright © 2000 American Chemical Society
Cite this:J. Am. Chem. Soc. 2000, 122, 8, 1729-1739
Equilibria, Kinetics, and Mechanism in the Bicarbonate Activation of Hydrogen Peroxide:
Oxidation of Sulfides by Peroxymonocarbonate - Journal of the American Chemical Society (ACS Publications) https://pubs.acs.org/doi/abs/10.1021/ja9927467
碳酸氢盐活化过氧化氢和硫芥子气和神经毒气模拟物的有效去污
Bicarbonate-activated hydrogen peroxide and efficient decontamination of toxic sulfur mustard and nerve gas simulants
强调
• 产生高反应性HCO4-，（CO2）2 *→2CO2 + hv控制活化。
• 高效破坏对氧磷，茴香硫醚，芥子气，梭曼。
• CeO2纳米颗粒通过·O2-抑制亚砜的氧化。
• 9-10是CWA的亲核/氧化净化的最佳pH范围。
摘要
13C NMR谱显示在NaHCO 3活化的H 2 O 2溶液中产生过氧一碳酸酯（HCO 4 - ），并且pH是其生产中的关键因素。
基于NMR，电子顺磁共振，化学发光分析的结果，提出碳酸氢根阴离子的循环为HCO3-→HCO3→（CO2）2 *→CO2（aq）→HCO4-（H2CO4）→HCO3-（HCO3）。在该循环中，（CO 2）2 *是关键中间体，（CO 2）2 *→2CO 2 + hv是速率控制步骤。
硫代芥子气和对氧磷分别是硫芥子气和神经毒气的模拟物，通过NaHCO3活化的H2O2溶液有效地净化。虽然HCO4-是硫代苯甲醚氧化的主要氧化剂，但在HCO4-或H2O2分解过程中产生的O2-导致硫化物的二次氧化。对氧磷在NaHCO3活化的H2O2溶液中通过OOH-和OH-的亲核取代而降解，并且降解速率随着pH的增加呈指数增加。
碱金属离子对对氧磷的降解具有催化作用。
芥子气和梭曼在NaHCO3活化的H2O2中有效降解成无毒产品。发现9-10的pH范围对于使用NaHCO 3活化的H 2 O 2的化学战剂和其他生态毒物的广谱净化是最佳的。
Bicarbonate-activated hydrogen peroxide and efficient decontamination of toxic sulfur mustard and nerve gas simulants
Author links open overlay panelSanpingZhao HailingXiaYan junZuobQiWangaZhichengWangbZengyuanYanb
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https://doi.org/10.1016/j.jhazmat.2017.09.055Get rights and content
Highlights
• Highly reactive HCO4− generated, (CO2)2* → 2 CO2 + hv controls the activation.
• Efficient destruction of paraoxon, thioanisole, mustard gas, soman.
• CeO2 nanoparticles inhibit the oxidation of sulfoxide by ·O2−.
• 9–10 is the optimal pH range for nucleophilic/oxidizing decontamination of CWAs.
Abstract
13C NMR spectra showed that peroxymonocarbonate (HCO4−) was generated in the NaHCO3-activated H2O2 solution and pH was a key factor in its production.
A cycle for the bicarbonate anion was proposed as HCO3− → HCO3 → (CO2)2* → CO2(aq) → HCO4− (H2CO4) → HCO3− (HCO3) basing on the results of NMR, electron paramagnetic resonance, chemiluminescence analysis.
In this cycle, (CO2)2* was the key intermediate and (CO2)2* → 2CO2 + hv was the rate controlling step.
Thioanisole and paraoxon, the simulants of sulfur mustard gas and nerve gas, respectively, were efficiently decontaminated by the NaHCO3-activated H2O2 solution.
While HCO4− was the primary oxidant for the oxidation of thioanisole, O2− generated during the decomposition of HCO4− or H2O2 led to the secondary oxidation of the sulfide. Paraoxon was degraded in the NaHCO3-activated H2O2 solution via nucleophilic substitution by OOH− and OH−, and the degradation rate increased exponentially with increasing pH.
Alkali metal ions had a catalytic effect on the degradation of paraoxon.
Mustard gas and soman degraded efficiently into nontoxic products in NaHCO3-activated H2O2. A pH range of 9–10 was found to be optimum for the broad-spectrum decontamination of chemical warfare agents and other eco-toxicants using NaHCO3-activated H2O2.
SOURCE:
SanpingZhao HailingXia YanjunZuo QiWanga ZhichengWang ZengyuanYan
Environment Science & Engineering, State Key Laboratory of NBC Protection for Civilian, Beijing China
Bicarbonate-activated hydrogen peroxide and efficient decontamination of toxic sulfur mustard and nerve gas simulants - ScienceDirect https://www.sciencedirect.com/science/article/pii/S0304389417307458
过氧单碳酸酯（HCO4-）在碳酸氢盐/二氧化碳配对对刺激生物硫醇过氧化反应中的作用
A Role for Peroxymonocarbonate in the Stimulation of Biothiol Peroxidation by the Bicarbonate/Carbon Dioxide Pair
摘要
过氧单碳酸酯（HCO4-）是一种氧化剂，自20世纪80年代以来就已知与过氧化氢和碳酸氢盐平衡存在。
最近，已提出过氧一碳酸酯介导由碳酸氢盐/二氧化碳对刺激的氧化过程。为了更好地理解这种新兴的生物氧化剂，我们通过13C NMR重新检查了其由过氧化氢和碳酸氢盐/二氧化碳形成的动力学。此外，我们通过动力学和产物分析研究了其在碳酸氢盐对生物硫醇（GSH和BSA-cysSH）过氧化作用的加速作用中的作用。
估算过氧一碳酸酯形成和衰变的速率常数并测定Keq值（pH 7.2，在25和37℃;在不存在和存在BSA和1-棕榈酰-2-脂酰基-sn-甘油-3-磷酸胆碱的脂质体的情况下）磷脂酰胆碱）。值得注意的是，此处估算的过氧一碳酸盐形成的速率常数（k1~10-2M-1s-1）比先前报道的值高1个数量级。
此外，显示过氧一碳酸酯平衡受BSA，脂质体和碳酸酐酶模拟物的影响。在不存在和存在BSA（分别在37℃下0.35和0.48M-1）下测定的Keq值用于分析在碳酸氢盐（2-25mM）存在下BSA-cysSH和GSH过氧化的动力学。
实验数据与模拟的良好拟合表明，过氧一碳酸酯是在碳酸氢盐存在下负责生物硫醇过氧化的主要物种。结果表明，过氧一碳酸酯是一种可行的生物氧化剂，除了支持主要生理缓冲液具有氧化还原活性的新兴数据。
A Role for Peroxymonocarbonate in the Stimulation of Biothiol Peroxidation by the Bicarbonate/Carbon Dioxide Pair
Abstract
Abstract Image
Peroxymonocarbonate (HCO4-) is an oxidant whose existence in equilibrium with hydrogen peroxide and bicarbonate has been known since the 1980s. More recently, peroxymonocarbonate has been proposed to mediate oxidative processes stimulated by the bicarbonate/carbon dioxide pair. To better understand this emerging biological oxidant, we re-examined the kinetics of its formation from hydrogen peroxide and bicarbonate/carbon dioxide by 13C NMR. Also, we studied its role in the accelerating effects of bicarbonate on biothiol (GSH and BSA-cysSH) peroxidation by kinetics and product analysis. The rate constants for peroxymonocarbonate formation and decay were estimated and Keq values determined (pH 7.2, at 25 and 37 °C; in the absence and presence of BSA and liposomes of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine phosphatidylcholine). Noteworthy is the fact the rate constant for peroxymonocarbonate formation estimated here (k1 ∼10-2 M-1 s-1) was more than 1 order of magnitude higher than a previously reported value. Also, peroxymonocarbonate equilibrium was shown to be affected by BSA, liposomes, and a carbonic anhydrase mimetic. The Keq values determined in the absence and presence of BSA (0.35 and 0.48 M-1, respectively, at 37 °C) were employed to analyze the kinetics of BSA-cysSH and GSH peroxidation in the presence of bicarbonate (2−25 mM). A good fit of experimental data with simulations indicated that peroxymonocarbonate is the main species responsible for biothiol peroxidation in the presence of bicarbonate. The results indicate that peroxymonocarbonate is a feasible biological oxidant, in addition to supporting emerging data that the main physiological buffer is redox active.
Daniel F. Trindade, Giselle Cerchiaro, and Ohara Augusto*
Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, CP 26077, CEP 05513-970, São Paulo, SP, Brazil
Chem. Res. Toxicol., 2006, 19 (11), pp 1475–1482
DOI: 10.1021/tx060146x
Publication Date (Web): November 4, 2006
Copyright © 2006 American Chemical Society
Cite this:Chem. Res. Toxicol. 2006, 19, 11, 1475-1482
A Role for Peroxymonocarbonate in the Stimulation of Biothiol Peroxidation by the Bicarbonate/Carbon Dioxide Pair - Chemical Research in Toxicology (ACS Publications) https://pubs.acs.org/doi/abs/10.1021/tx060146x
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