Xylenol-orange-assay-of-hydrogen-peroxide for Measuring Uricase Activity and Recognizing High-activity Uricase Mutant

2013 ◽  
Vol 19 (3) ◽  
pp. 523-527 ◽  
Author(s):  
Miaomiao LIU ◽  
Juan FENG ◽  
Hongbo LIU ◽  
Xiaolan YANG ◽  
Liping FENG ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
High Activity ◽  
Xylenol Orange ◽  
Uricase Activity

Au (Core)–Pt (Shell) Nanocatalysts with the Shell Thickness Controlled at a Monolayer Level: Extremely High Activity for Hydrogen Peroxide Decomposition

2018 ◽  
Vol 122 (40) ◽  
pp. 22953-22958 ◽  
Author(s):  
Shin-ichi Naya ◽  
Satoshi Miki ◽  
Junpei Yamauchi ◽  
Miwako Teranishi ◽  
Hisayoshi Kobayashi ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
High Activity ◽  
Shell Thickness ◽  
Hydrogen Peroxide Decomposition ◽  
Peroxide Decomposition

scholarly journals Selective electrochemical production of hydrogen peroxide at zigzag edges of exfoliated molybdenum telluride nanoflakes

2020 ◽  
Vol 7 (8) ◽  
pp. 1360-1366 ◽  
Author(s):  
Xuan Zhao ◽  
Yu Wang ◽  
Yunli Da ◽  
Xinxia Wang ◽  
Tingting Wang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
High Activity ◽  
Molecular Oxygen ◽  
Large Mass ◽  
Binding Energies ◽  
Hydrogen Electrode ◽  
Production Of Hydrogen ◽  
Activity Onset ◽  
Electrochemical Production ◽  
Electron Reduction

Abstract The two-electron reduction of molecular oxygen represents an effective strategy to enable the green, mild and on-demand synthesis of hydrogen peroxide. Its practical viability, however, hinges on the development of advanced electrocatalysts, preferably composed of non-precious elements, to selectively expedite this reaction, particularly in acidic medium. Our study here introduces 2H-MoTe2 for the first time as the efficient non-precious-metal-based electrocatalyst for the electrochemical production of hydrogen peroxide in acids. We show that exfoliated 2H-MoTe2 nanoflakes have high activity (onset overpotential ∼140 mV and large mass activity of 27 A g−1 at 0.4 V versus reversible hydrogen electrode), great selectivity (H2O2 percentage up to 93%) and decent stability in 0.5 M H2SO4. Theoretical simulations evidence that the high activity and selectivity of 2H-MoTe2 arise from the proper binding energies of HOO* and O* at its zigzag edges that jointly favor the two-electron reduction instead of the four-electron reduction of molecular oxygen.

scholarly journals Direct amide synthesis over core–shell TiO2@NiFe2O4 catalysts in a continuous flow radiofrequency-heated reactor

RSC Advances ◽  
2016 ◽  
Vol 6 (103) ◽  
pp. 100997-101007 ◽  
Author(s):  
Yawen Liu ◽  
Pengzhao Gao ◽  
Nikolay Cherkasov ◽  
Evgeny V. Rebrov
Keyword(s):  
Hydrogen Peroxide ◽  
High Activity ◽  
Continuous Flow ◽  
Hydrogen Peroxide Solution ◽  
Core Shell ◽  
Amide Synthesis

A core–shell TiO2@NiFe2O4 catalyst showed high activity and stability in direct amide synthesis with easy regeneration from coke by a treatment with a 30 wt% hydrogen peroxide solution.

Automatic measurements of hydrogen peroxide utilizing a Xylenol Orange-titanium system

1968 ◽  
Vol 40 (2) ◽  
pp. 465-466 ◽  
Author(s):  
Carleton D. Nordschow ◽  
Arnold R. Tammes
Keyword(s):  
Hydrogen Peroxide ◽  
Xylenol Orange

Iron(III) Complexes with Hydrogen Peroxide which Can Discriminate Two Reaction Types; Oxidation (H-Atom Abstraction) and Oxygenation Reaction

1995 ◽  
Vol 50 (3-4) ◽  
pp. 205-208 ◽  
Author(s):  
Yuzo Nishida ◽  
Sayo Ito
Keyword(s):  
Hydrogen Peroxide ◽  
Acid Solution ◽  
High Activity ◽  
Oxidative Degradation ◽  
Nitrilotriacetic Acid ◽  
Diacetic Acid ◽  
Experimental Conditions

Iron(III)-NTA (nitrilotriacetic acid) solution shows high activity for oxidative degradation of 2′-deoxyribose in the presence of hydrogen peroxide, whereas its activity of Fe(III)-TFDA (2-aminomethyltetrahydrofuran-N,N-diacetic acid) is negligible under the same experimental conditions; however the latter solution exhibits abnormally higher reactivity for oxygenation reaction at 8-position of 2′-deoxyguanosine than other iron(III) chelates examined. These results suggest that oxidative degradation of deoxyribose and the oxygenation of deoxyguanosine are caused by a different iron(III)-peroxide species.

Structural Variety of Copper(II)-Peroxide Adducts and Its Relevance to DNA Cleavage

1999 ◽  
Vol 54 (1-2) ◽  
pp. 94-99 ◽  
Author(s):  
Satoshi Nishino ◽  
Teruyuki Kobayashi ◽  
Mami Kunita ◽  
Sayo Ito ◽  
Yuzo Nishida
Keyword(s):  
Hydrogen Peroxide ◽  
High Activity ◽  
Dna Cleavage ◽  
Esr Spectroscopy ◽  
Spin Trapping ◽  
The Other ◽  
Experimental Conditions ◽  
Structural Variety ◽  
Supercoiled Form ◽  
Tetradentate Ligands

The reactivity of copper(II) compounds with several tetradentate ligands towards some spin-trapping reagents was studied in the presence of hydrogen peroxide. The compounds used in this study are roughly divided into two groups based on the reactivity towards 2 ,2 ,6 ,6 -tetramethyl-4-piperidinol(and also 2,2,6,6-tetramethyl-4-piperidone), which are trapping agents for singlet oxygen, 1O2 (1Δg); The A-group compounds exhibited a high activity to form the corresponding nitrone radical, which was detected by ESR spectroscopy, but corresponding activity of the B-group compounds was very low. The A-group compounds defined as above exhibited high activity for cleavage of DNA(supercoiled Form I) in the presence of hydrogen peroxide, yielding DNA Form II (relaxed circular) or Form III (linear duplex) under our experimental conditions ([Cu(II)]=0.1~0.5 mᴍ). On the other hand, the B-group compounds effected complete degradation of the DNA (double-strand scission) under the same experimental conditions, formation of Form II or Form III DNA was negligible. Two different DNA cleavage patterns observed for A-and B-group compounds were elucidated by the different structural property of the copper(II)-peroxide adducts, which is controlled by the interaction through both DNA and the peripheral group of the ligand system

Preparation and Properties of a Cholesterol Oxidase from Nocardia sp. and Its Application to the Enzymatic Assay of Total Cholesterol in Serum

1973 ◽  
Vol 19 (12) ◽  
pp. 1350-1356 ◽  
Author(s):  
W Richmond
Keyword(s):  
Hydrogen Peroxide ◽  
Total Cholesterol ◽  
Enzyme Assay ◽  
Cholesterol Oxidase ◽  
Xylenol Orange ◽  
Extraction And Purification ◽  
Production Of Hydrogen ◽  
Nocardia Sp ◽  
Wide Ph Range ◽  
Ph Range

Abstract I describe the characterization, extraction, and purification of a cholesterol:oxygen oxidoreductase (EC 1.1.3.6) from Nocardia sp. This enzyme catalyzes oxidation of cholesterol to Δ4-choIestenone, with production of hydrogen peroxide. It is very stable, active over a wide pH range, and has a Km of 1.4 x 10-5 mol/ liter. It is highly specific for Δ4- or Δ5-3β-hydroxycholestanes, and may be applied to the assay of serum total cholesterol. In the procedure presented here, hydrogen peroxide is measured by reaction with quadrivalent titanium and xylenol orange. This constitutes a one-enzyme assay with stable reagents, which does not require protein precipitation and is not subject to interference from hemoglobin or bilirubin.

Contribution of a Peroxide Adduct of Copper(II)-Peptide Complex to Modify the Secondary Structure of Albumin

1998 ◽  
Vol 53 (5-6) ◽  
pp. 378-382 ◽  
Author(s):  
Yoshihiro Ishikawa ◽  
Sayo Ito ◽  
Satsohi Nishino ◽  
Shigeru Ohba ◽  
Yuzo Nishida
Keyword(s):  
Hydrogen Peroxide ◽  
Secondary Structure ◽  
High Activity ◽  
Prion Protein ◽  
Peptide Bond ◽  
Amide Group ◽  
Cellular Prion Protein ◽  
Peptide Group ◽  
Peptide Complex ◽  
Terminal Domain

Abstract Copper(II)-peroxide Adduct, Modification of Protein, Copper(II)-peptide Complex We have found that copper(II) compounds containing a peptide group in the chelate exhibit high activity for modification or degradation of albumin in the presence of hydrogen peroxide, whereas no activity was detected for the copper(II) compounds without an amide-group. It is suggested that presence of the amide-group in the ligand may play an important role in the formation of a peroxide adduct and in activation of the peroxide ion, leading to cleavage of the peptide bond of a neighboring protein. It is implied that conversion of normal cellular prion protein PrPC into a disease-causing isoform, PrPSc is attributed to the activated peroxide ion coordinated to a copper(II) captured in the NH2-terminal domain of the PrPC .

scholarly journals Selective Allylic Oxidation of Terpenic Olefins Using Co-Ag Supported on SiO2 as a Novel, Efficient, and Recyclable Catalyst

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Abderrazak Aberkouks ◽  
Ayoub Abdelkader Mekkaoui ◽  
Mustapha Ait Ali ◽  
Larbi El Firdoussi ◽  
Soufiane El Houssame
Keyword(s):  
Hydrogen Peroxide ◽  
High Activity ◽  
Oxidation Reaction ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Allylic Oxidation ◽  
Catalyst Amount ◽  
Gel Method ◽  
Ft Ir ◽  
Butyl Peroxide

Co-Ag supported on the SiO2 catalyst was synthesized by the sol-gel method and characterized using XRD, FT-IR, TG-DTG, BET, CV, and SEM/EDX analysis. The catalytic performance of the resulting catalyst was examined by the oxidation of mono and sesquiterpenic olefins using hydrogen peroxide and tert-butyl peroxide as oxidant agents. Various parameters such as catalyst amount, temperature, and solvents have been studied. The Co-Ag supported on the SiO2 catalyst showed a high activity, selectivity, and recyclability for the selected oxidation reaction.

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