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.

Automated enzymic measurement of total cholesterol in serum.

1978 ◽  
Vol 24 (1) ◽  
pp. 108-114 ◽  
Author(s):  
G S Rautela ◽  
R J Liedtke
Keyword(s):  
Hydrogen Peroxide ◽  
Total Cholesterol ◽  
Response Surface ◽  
Computer Analysis ◽  
Free Cholesterol ◽  
Cholesterol Oxidase ◽  
Cholesterol Esters ◽  
Direct Proportion ◽  
Analytical Test ◽  
Response Surface Designs

Abstract We describe a completely automated enzymic system for measuring total cholesterol in serum. All reagents are contained in an analytical test pack and the test is performed on Du Pont's Automatic Clinical Analyzer (aca), which mixes the sample (20 microliter) and reagents and performs the necessary absorbance measurements and calculations. In the procedure, cholesterol oxidase oxidizes free cholesterol. The oxidation step produces cholest-4-en-3-one and hydrochloride peroxidesterase hydrolyzes cholesterol esters and cholesterol in direct proportion to the amount of cholesterol present. N,N-Diethylaniline hydrochloride and 4-aminoantipyrine react with the hydrogen peroxide to produce a quinoneimine dye (lambda max = 553 nm). Interacting reagents have been optimized simultaneously (coöptimization) utilizing response surface designs coupled with computer analysis of the data. Reagent efficiency is high and analytical performance reliable.

scholarly journals Preparation of a series of N-alkyl-3-boronopyridinium halides and study of their stability in the presence of hydrogen peroxide

2012 ◽  
Vol 10 (4) ◽  
pp. 1059-1065 ◽  
Author(s):  
Yevgen Karpichev ◽  
Hubert Matondo ◽  
Illia Kapitanov ◽  
Oleksandr Savsunenko ◽  
Marc Vedrenne ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Thermal Degradation ◽  
Microwave Irradiation ◽  
Room Temperature ◽  
Ester Hydrolysis ◽  
Water Solutions ◽  
Boronic Ester ◽  
Wide Ph Range ◽  
Ph Range

AbstractA simple and efficient protocol for the preparation of a series of N-alkyl-3-boronopyridinium salts is described which requires exposure of 3-pyridineboronic acid neopentylglycol ester and corresponding alkyle halide to microwave irradiation followed by boronic ester hydrolysis. The technique employed drastically reduces the reaction time and prevents thermal degradation and the formation of side products. Water solutions of the obtained boronopyridinium salts are shown to be stable at room temperature in wide pH range as well as in the presence of hydrogen peroxide at pH 10.0 for 72 h.

Removing dye Rhodamine B from aqueous medium via wet peroxidation with V-MCM-41 and H2O2

2009 ◽  
Vol 59 (3) ◽  
pp. 565-571 ◽  
Author(s):  
Deyong Wu ◽  
Mingce Long ◽  
Chao Chen ◽  
Yahui Wu ◽  
Weimin Cai ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Visible Light Irradiation ◽  
Rhodamine B ◽  
Mesoporous Structure ◽  
Heterogeneous Fenton ◽  
Bet Method ◽  
Wide Ph Range ◽  
Ph Range ◽  
Tetraethyl Silicate ◽  
Mcm 41

A new heterogeneous Fenton-like system, consisting of V-MCM-41 catalyst and hydrogen peroxide, was proved to be effective in removing recalcitrant dye Rhodamine B (RhB) in aqueous solutions. V-MCM-41 was prepared following a direct hydrothermal procedure with tetraethyl silicate and ammonium metavanadate as precursor. The mesoporous structure has been characterized by XRD, and the specific surface area was determined as x m2 g−1 according to BET method. The catalytic reaction can proceed in a relatively wide pH range from acidic to alkaline. And the visible light irradiation cannot promote the reaction process. In addition, the mechanism implication for V-MCM-41 as a Fenton-like catalyst has been discussed.

scholarly journals Novel Enzyme-Free Multifunctional Bentonite/Polypyrrole/Silver Nanocomposite Sensor for Hydrogen Peroxide Detection over a Wide pH Range

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4442 ◽  
Author(s):  
Khouloud Jlassi ◽  
Mostafa H. Sliem ◽  
Kamel Eid ◽  
Igor Krupa ◽  
Mohamed M. Chehimi ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Ag Nanoparticles ◽  
Rational Design ◽  
Uv Light ◽  
Low Cost ◽  
Current Response ◽  
Ag Nps ◽  
Hydrogen Peroxide Detection ◽  
Wide Ph Range ◽  
Ph Range

Precise designs of low-cost and efficient catalysts for the detection of hydrogen peroxide (H2O2) over wide ranges of pH are important in various environmental applications. Herein, a versatile and ecofriendly approach is presented for the rational design of ternary bentonite-silylpropyl-polypyrrole/silver nanoarchitectures (denoted as BP-PS-PPy/Ag) via the in-situ photo polymerization of pyrrole with salinized bentonite (BP-PS) in the presence of silver nitrate. The Pyrrolyl-functionalized silane (PS) is used as a coupling agent for tailoring the formation of highly exfoliated BP-PS-PPy sheet-like nanostructures ornamented with monodispersed Ag nanoparticles (NPs). Taking advantage of the combination between the unique physicochemical properties of BP-PS-PPy and the outstanding catalytic merits of Ag nanoparticles (NPs), the as-synthesized BP-PS-PPy/Ag shows a superior electrocatalytic reduction and high-detection activity towards H2O2 under different pH conditions (from 3 to 10). Intriguingly, the UV-light irradiation significantly enhances the electroreduction activity of H2O2 substantially, compared with the dark conditions, due to the high photoelectric response properties of Ag NPs. Moreover, BP-PS-PPy/Ag achived a quick current response with a detection limit at 1 μM within only 1 s. Our present approach is green, facile, scalable and renewable.

scholarly journals GPCC catalyzed hydrogen peroxide for decolorization of C.I. Reactive Red 24 from simulated dyeing wastewater

2020 ◽  
Vol 82 (11) ◽  
pp. 2381-2388
Author(s):  
Jie Wang ◽  
Xueyan Wang
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic System ◽  
Copper Complex ◽  
Dyeing Wastewater ◽  
Decolorization Rate ◽  
Wide Ph Range ◽  
Ph Range

Abstract A kind of gelatin protein copper complex (GPCC for short) was synthesized by us. GPCC acting as catalyst was applied to catalyzed hydrogen peroxide for decolorization of C.I. Reactive Red 24 from simulated dyeing wastewater. The influence of catalyzed hydrogen peroxide by GPCC on the decolorization of C.I. Reactive Red 24 from simulated dyeing wastewater was discussed. The optimum decolorization technology condition was optimized. And the effect of salt on decolorization of C.I. Reactive Red 24 in this catalytic system was also investigated. The results showed that hydrogen peroxide can be catalyzed by GPCC. In the catalytic system, the structure of C.I. Reactive Red 24 can be degraded and a high decolorization rate can be obtained in a wide pH range. In addition, the decolorization percentage and decolorization rate will be further improved when salt is present in the catalytic system.

Use of cholesterol oxidase for assay of total and free cholesterol in serum by continuous-flow analysis.

1976 ◽  
Vol 22 (10) ◽  
pp. 1579-1588 ◽  
Author(s):  
W Richmond
Keyword(s):  
Total Cholesterol ◽  
Continuous Flow ◽  
Free Cholesterol ◽  
Cholesterol Oxidase ◽  
Xylenol Orange ◽  
Flow Analysis ◽  
Dual Channel ◽  
Aqueous Micellar Solution ◽  
Continuous Flow Analysis ◽  
Triton X

Abstract Idescribe an assay for total cholesterol in serum, with use of the AutoAnalyzer ii (Technicon), in which cholesterol esters are saponified by alkali, cholesterol is held in aqueous micellar solution with a surfactant (Triton X-100) and oxidized by cholesterol oxidase, and the hydrogen peroxide produced is measured by chelation with Ti4+ and xylenol orange. An assay for free cholesterol in serum, based on similar principles, is also described, and the two can be run simultaneously on a dual-channel AutoAnalyzer II. Standard solutions of cholesterol in isopropanol have poorer carryover characteristics than sera, and therefore do not reach the same continuous-flow steady state as sera of equivalent concentrations. Consequent potential calibration errors are avoided by using micellar solutions of cholesterol containing albumin for standardization. The formation of cholesterol peroxide in solutions of cholesterol in isopropanol is demonstrated, and this constitutes another potential source of error in the calibration of enzymic cholesterol assays. In analyzing patients' sera, results of the total cholesterol assay correlate well with those of a mechanized method in which cholesterol esterase and cholesterol oxidase are used; an automated Abell method, calibrated with solutions of cholesterol in isopropanol, gave slightly higher values. Determinations of the ratio of free cholesterol to total cholesterol by our automated cholesterol exidase assays given values that agree well with published results in which digitonin precipitation is used.

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

Polarographic and spectrophotometric behaviour of some N-p-phenyl substituted benzamidines

1991 ◽  
Vol 56 (12) ◽  
pp. 2791-2799 ◽  
Author(s):  
Juan A. Squella ◽  
Luis J. Nuñez-Vergara ◽  
Hernan Rodríguez ◽  
Amelia Márquez ◽  
Jose M. Rodríguez-Mellado ◽  
...  
Keyword(s):  
Spectrophotometric Study ◽  
Absorption Bands ◽  
Electrochemical Parameters ◽  
Wide Ph Range ◽  
Group A ◽  
Substituent Constants ◽  
Ph Range ◽  
The Waves

Five N-p-phenyl substituted benzamidines were studied by DC and DP polarography in a wide pH range. Coulometric results show that the overall processes are four-electron reductions. Logarithmic analysis of the waves indicate that the process are irreversible. The influence of the pH on the polarographic parameters was also studied. A UV spectrophotometric study was performed in the pH range 2-13. In basic media some variations in the absorption bands were observed due to the dissociation of the amidine group. A determination of the pK values was made by deconvolution of the spectra. Correlations of both the electrochemical parameters and spectrophotometric pK values with the Hammett substituent constants were obtained.

scholarly journals Photocatalytic Production of Hydrogen Peroxide over Modified Semiconductor Materials: A Minireview

2020 ◽  
Vol 63 (9-10) ◽  
pp. 895-912
Author(s):  
Haiyan Song ◽  
Lishan Wei ◽  
Luning Chen ◽  
Han Zhang ◽  
Ji Su
Keyword(s):  
Hydrogen Peroxide ◽  
Semiconductor Materials ◽  
Production Of Hydrogen
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