69-78-3Relevant articles and documents
Investigation of solvent-dependent catalytic behaviour of hydrophobic guest artificial glutathione peroxidase using H2O2 and 3-carboxyl-4-nitrobenzenethiol as substrates
Zhang,Yin,Jiao,Zheng,Zhong,Gan,Li,Huang,Zhan
, p. 3799 - 3802 (2015)
The investigation of the catalytic behaviour of a hydrophobic guest artificial glutathione peroxidase (GPx) (ADA-Te-OH) was carried out employing H2O2 and 3-carboxyl-4-nitrobenzenethiol (TNB) as substrates. The relation between the catalytic rate of ADA-Te-OH and the property of solvent used in the determination of catalytic activity was revealed. Typically, the co-solvents including ethanol, DMSO, DMF and CH3CN were employed in the determination of catalytic rates. It indicated that ADA-Te-OH exhibited the typical solventdependent catalytic behaviour. Especially, higher catalytic rate was observed when polar protic solvent (ethanol) was used compared with other co-solvents. It suggested that polar protic solvent was the appropriate co-solvent for the assay of catalytic activity of hydrophobic artificial glutathione peroxidase. Additionally, the strong polarity of polar aprotic solvent plays an important role in the enhancement of glutathione peroxidase catalytic activity. This study embodies well understanding of the catalytic behaviour of hydrophobic guest artificial glutathione peroxidase.
Aryl thiol substrate 3-carboxy-4-nitrobenzenethiol strongly stimulating thiol peroxidase activity of glutathione peroxidase mimic 2, 2′-ditellurobis(2-deoxy-β-cyclodextrin)
Dong, Zeyuan,Liu, Junqiu,Mao, Shizhong,Huang, Xin,Yang, Bing,Ren, Xiaojun,Luo, Guimin,Shen, Jiacong
, p. 16395 - 16404 (2004)
Artificial glutathione peroxidase (GPx) model 2, 2′-ditellurobis(2- deoxy-β-cyclodextrin) (2-TeCD) which has the desirable properties exhibited high substrate specificity and remarkably catalytic efficiency when 3-carboxy-4-nitrobenzenethiol (ArSH) was used as a preferential thiol substrate. The complexation of ArSH with β-cyclodextrin was investigated through UV spectral titrations, fluorescence spectroscopy, 1H NMR and molecular simulation, and these results indicated that ArSH fits well to the size of the cavity of β-cyclodextrin. Furthermore, 2-TeCD was found to catalyze the reduction of cumene peroxide (CuOOH) by ArSH 200 000-fold more efficiently than diphenyl diselenide (PhSeSePh). Its steady-state kinetics was studied and the second rate constant kmax/KArSH was found to be 1.05 × 107 M-1 min-1 and similar to that of natural GPx. Moreover, the kinetic data revealed that the catalytic efficiency of 2-TeCD depended strongly upon the competitive recognition of both substrates for 2-TeCD. The catalytic mechanism of 2-TeCD catalysis agreed well with a ping-pong mechanism, in analogy with natural GPx, and might exert its thiol peroxidase activity via tellurol, tellurenic acid, and tellurosulfide.
Switching between inner- and outer-sphere PCET mechanisms of small-molecule activation: Superoxide dismutation and oxygen/superoxide reduction reactivity deriving from the same manganese complex
Kenkel, Isabell,Franke, Alicja,Dürr, Maximilian,Zahl, Achim,Dücker-Benfer, Carlos,Langer, Jens,Filipovi?, Milos R.,Yu, Meng,Puchta, Ralph,Fiedler, Stephanie R.,Shores, Matthew P.,Goldsmith, Christian R.,Ivanovi?-Burmazovi?, Ivana
, p. 1472 - 1484 (2017)
Readily exchangeable water molecules are commonly found in the active sites of oxidoreductases, yet the overwhelming majority of studies on small-molecule mimics of these enzymes entirely ignores the contribution of water to the reactivity. Studies of how these enzymes can continue to function in spite of the presence of highly oxidizing species are likewise limited. The mononuclear MnII complex with the potentially hexadentate ligand N-(2-hydroxy-5-methylbenzyl)-N,N′,N′-tris(2-pyridinylmethyl)-1,2-ethanediamine (LOH) was previously found to act as both a H2O2-responsive MRI contrast agent and a mimic of superoxide dismutase (SOD). Here, we studied this complex in aqueous solutions at different pH values in order to determine its (i) acid-base equilibria, (ii) coordination equilibria, (iii) substitution lability and operative mechanisms for water exchange, (iv) redox behavior and ability to participate in proton-coupled electron transfer (PCET) reactions, (v) SOD activity and reductive activity toward both oxygen and superoxide, and (vi) mechanism for its transformation into the binuclear MnII complex with (H)OL-LOH and its hydroxylated derivatives. The conclusions drawn from potentiometric titrations, low-temperature mass spectrometry, temperature- and pressure-dependent 17O NMR spectroscopy, electrochemistry, stopped-flow kinetic analyses, and EPR measurements were supported by the structural characterization and quantum chemical analysis of proposed intermediate species. These comprehensive studies enabled us to determine how transiently bound water molecules impact the rate and mechanism of SOD catalysis. Metal-bound water molecules facilitate the PCET necessary for outer-sphere SOD activity. The absence of the water ligand, conversely, enables the inner-sphere reduction of both superoxide and dioxygen. The LOH complex maintains its SOD activity in the presence of ?OH and MnIV-oxo species by channeling these oxidants toward the synthesis of a functionally equivalent binuclear MnII species. (Figure Presented).
Construction of pH sensitive smart glutathione peroxidase (GPx) mimics based on pH responsive pseudorotaxanes
An, Shaojie,Jia, Wenlong,Li, Jiaxi,Ma, Ganghui,Shi, Shan,Wang, Tao,Zhang, Xiaoyin
, p. 3125 - 3134 (2020/05/08)
Two organoselenium compounds, both of which were modified with two primary amine groups, were designed and synthesized to mimic the catalytic properties of glutathione peroxidase (GPx). It was demonstrated that the catalytic mechanism of the diselenide organoselenium compound (compound 1) was a ping-pong mechanism while that of the selenide organoselenium compound (compound 2) was a sequential mechanism. The pH-controlled switching of the catalytic activities was achieved by controlling the formation and dissociation of the pseudorotaxanes based on the organoselenium compounds and cucurbit[6]uril (CB[6]). Moreover, the switching was reversible at pH between 7 and 9 for compound 1 or between 7 and 10 for compound 2.
Total synthesis method of DTNB (5,5'-Dithiobis-(2-nitrobenzoic acid))
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, (2019/03/29)
The invention discloses a total synthesis method of DTNB (5,5'-Dithiobis-(2-nitrobenzoic acid)), which comprises the steps of: nitrification: dropwise adding mixed acid into m-bromotoluene to form 2-nitryl-5-bromotoluene, oxidation: adding 2-8wt% of potassium permanganate solution into 2-nitryl-5-bromotoluene to form 2-nitryl-5-bromine-benzoate, and vulcanization: dissolving 2-nitryl-5-bromine-benzoate prepared in the oxidation step in water, regulating a pH (potential of hydrogen) to be greater than 3.5, stirring and heating to 45-55 DEG C, adding a sodium sulfide aqueous solution in batches,holding the temperature for reaction for 2h, regulating the pH to be less than 1 with hydrochloric acid, and collecting a precipitate to form DTNB. The total synthesis method of DTNB is short in synthesis route, strong in production controllability, lower in cost and easy in industrial production, and a total yield in a synthesis process is above 35%.
Wavelength-Controlled Dynamic Metathesis: A Light-Driven Exchange Reaction between Disulfide and Diselenide Bonds
Fan, Fuqiang,Ji, Shaobo,Sun, Chenxing,Liu, Cheng,Yu, Ying,Fu, Yu,Xu, Huaping
supporting information, p. 16426 - 16430 (2018/11/23)
Wavelength-controlled dynamic processes are mostly based on light-triggered isomerization or the cleavage/formation of molecular connections. Control over dynamic metathesis reactions by different light wavelengths, which would be useful in controllable dynamic chemistry, has rarely been studied. Taking advantage of the different bond energies of disulfide and diselenide bonds, we have developed a wavelength-driven exchange reaction between disulfides and diselenides, which underwent metathesis under UV light to produce Se?S bonds. When irradiated with visible light, the Se?S bonds were reversed back to those of the original reactants. The conversion of the exchange depends on the wavelength of the incident light. This light-driven metathesis chemistry was also applied to tune the mechanical properties of polymer materials. The visible-light-induced reverse reaction was compatible with reductant-catalyzed disulfide/diselenide metathesis, and could be utilized to develop a dissipative system with light as the energy input.
Solvent-dependent catalytic behavior of telluride-containing guest artificial glutathione peroxidase using cumene hydroperoxide and 3-carboxyl-4-nitrobenzenethiol as substrates
Jiao,Yin,Zhang,Zhong,Wang,Zhang,Yang
, p. 2665 - 2668 (2015/12/11)
To reveal the solvent-dependent catalytic behaviour of a hydrophobic telluride-containing guest artificial glutathione peroxidase (ADA-Te-OH), the catalytic rates were investigated using cumene hydroperoxide and 4-nitrobenzenethiol as substrates. Herein, ethanol, DMSO, DMF and CH3CN were selected as the co-solvents in the determination of catalytic rates. Significantly, the typical solvent-dependent catalytic behaviour of ADA-Te-OH was observed. Especially, the higher catalytic rate was observed when polar protic solvent (ethanol) was used compared with other co-solvents. It suggested that polar protic solvent was the appropriate co-solvent for the assay of catalytic activity of hydrophobic artificial glutathione peroxidase. This study well for the understanding of the catalytic behaviour of hydrophobic guest artificial glutathione peroxidase.
A smart artificial glutathione peroxidase with temperature responsive activity constructed by host-guest interaction and self-assembly
Yin, Yanzhen,Jiao, Shufei,Lang, Chao,Liu, Junqiu
, p. 25040 - 25050 (2014/07/07)
A smart supramolecular artificial glutathione peroxidase (GPx) with tunable catalytic activity was prepared based on host-guest interaction and a blending process. The functional guest molecules ADA-Te with catalytic center, ADA-Arg with binding site and the cyclodextrin-containing host polymers (CD-PNIPAMs) were first synthesized. The artificial glutathione peroxidase was constructed by host-guest interaction of ADA-Te and a series of CD-PNIPAMs with different molecular weights. Through altering the molar ratio of building blocks (CD-PNIPAM73, ADA-Te, ADA-Arg), the optimum artificial GPx (SGPx max) with vesicle structure was prepared via a blending process. Significantly, SGPxmax displayed a noticeable temperature responsive catalytic activity and exhibited typical saturation kinetics behavior of a real enzyme catalyst. It was proved that the change of the self-assembled structure of SGPxmax during the temperature responsive process played a significant role in altering the temperature responsive catalytic behavior. The construction of SGPxmax not only overcomes the insurmountable disadvantages existing in traditional supramolecular artificial GPxs but also bodes well for development of other biologically related functional supramolecular biomaterials.
A supramolecular microgel glutathione peroxidase mimic with temperature responsive activity
Yin, Yanzhen,Jiao, Shufei,Lang, Chao,Liu, Junqiu
, p. 3374 - 3385 (2014/05/20)
Glutathione peroxidase (GPx) protects cells from oxidative damage by scavenging surplus reactive oxygen species (ROS). Commonly, an appropriate amount of ROS acts as a signal molecule in the metabolism. A smart artificial GPx exhibits adjustable catalytic activity, which can potentially reduce the amount of ROS to an appropriate degree and maintain its important physiological functions in metabolism. To construct an optimum and excellent smart artificial GPx, a novel supramolecular microgel artificial GPx (SM-Te) was prepared based on the supramolecular host-guest interaction employing the tellurium-containing guest molecule (ADA-Te-ADA) and the cyclodextrin-containing host block copolymer (poly(N-isopropylacrylamide)-b-[polyacrylamides-co-poly(6-o-(triethylene glycol monoacrylate ether)-β-cyclodextrin)], PPAM-CD) as building blocks. Subsequently, based on these building blocks, SM-Te was constructed and the formation of its self-assembled structure was confirmed by dynamic light scattering, NMR, SEM, TEM, etc. Typically, benefitting from the temperature responsive properties of the PNIPAM scaffold, SM-Te also exhibited similar temperature responsive behaviour. Importantly, the GPx catalytic rates of SM-Te displayed a noticeable temperature responsive characteristic. Moreover, SM-Te exhibited the typical saturation kinetics behaviour of a real enzyme catalyst. It was proved that the changes of the hydrophobic microenvironment and the pore size in the supramolecular microgel network of SM-Te played significant roles in altering the temperature responsive catalytic behaviour. The successful construction of SM-Te not only overcomes the insurmountable disadvantages existing in previous covalent bond crosslinked microgel artificial GPx but also bodes well for the development of novel intelligent antioxidant drugs. This journal is the Partner Organisations 2014.
Construction of a smart glutathione peroxidase mimic with temperature responsive activity based on block copolymer
Yin, Yanzhen,Wang, Liang,Jin, Haiyan,Lv, Chunyan,Yu, Shuangjiang,Huang, Xin,Luo, Quan,Xu, Jiayun,Liu, Junqiu
experimental part, p. 2521 - 2529 (2012/02/05)
To construct a smart artificial antioxidative enzyme on a nano-scaffold, a novel method for designing glutathione peroxidase (GPx) active sites on block copolymer vesicles was developed by simple blending predesigned temperature-sensitive block copolymers with the main catalytic units of GPx. A series of functional block copolymers, poly(N-isopropylacrylamide)-b- polyacrylamides loaded with recognition and catalytic sites, were synthesized via ATRP and click chemistry. Through altering the molar ratio of the functional copolymers, the optimum GPx mimic based on copolymer vesicles was obtained by self-assembly of temperature-sensitive block copolymers through a blending process. Significantly, the catalytic activity of the optimum GPx mimic can be well modulated by changing the temperature. It was proved that the change in self-assembly structure of the block copolymer played an important role in the modulation of the catalytic activity. This method not only bodes well for designing smart antioxidative enzyme mimics that could be used in cosmetics as antioxidative additives but also highlights the construction of other regulatory biologically related functional biomaterials.
