Effect of Phenols on the Oxidation of Estradiol by Uterine Peroxidase

1975 ◽  
Vol 53 (8) ◽  
pp. 855-860 ◽  
Author(s):  
T. McNabb ◽  
J. Sproul ◽  
P. H. Jellinck
Keyword(s):  
Amino Acids ◽  
Hydrogen Peroxide ◽  
Water Soluble ◽  
The Other

The effect of various phenols on the conversion of [4-14C]estradiol to water-soluble products by estrogen-induced uterine peroxidase (EC 1.11.1.7) has been investigated. Evidence was provided that those phenols which enhanced the oxidation of estradiol exerted their effect by activating peroxidase or protecting the enzyme from inactivation by the products of the reaction rather than by inhibiting the breakdown of hydrogen peroxide by catalase (EC 1.11.1.6). It has also been shown that tyrosine acted both as an activator of uterine proxidase and as a water-soluble acceptor for the metabolites of estradiol. The ability of tyrosyl peptides to form conjugates with estradiol was influenced by the other amino acids and decreased with the number of adjacent tyrosyl residues.

THE OXIDATION OF ESTRONE-16-C14BY PEROXIDASE

1962 ◽  
Vol 40 (1) ◽  
pp. 459-469 ◽  
Author(s):  
P. H. Jellinck ◽  
Louise Irwin
Keyword(s):  
Amino Acids ◽  
Hydrogen Peroxide ◽  
Amino Acid ◽  
Serum Albumin ◽  
Oxidase Activity ◽  
Water Soluble ◽  
The Other ◽  
Aerobic Incubation ◽  
Nitrogenous Compounds ◽  
Initial Generation

Aerobic incubation of estrone-16-C14with peroxidase in the presence of serum albumin and other proteins resulted in the formation of water-soluble, ether-insoluble metabolites in high percentage yields. Similar products were formed when protein was replaced by cysteine or tryptophan but none of the other amino acids tested had any effect. The evidence points to an initial generation of hydrogen peroxide from these nitrogenous compounds by the enzyme acting as an aerobic oxidase, and the subsequent peroxidation of estrone to highly reactive products. These then combine with the protein or amino acid or else undergo alternative reactions. A strong chemical bond is formed with albumin and attempts to release the estrone metabolites from it were unsuccessful. Uterine homogenates from estrogen-treated rats showing high DPNH oxidase activity contained no "peroxidase" as measured by the formation of water-soluble products from estrone in the presence of protein.

THE OXIDATION OF ESTRONE-16-C14BY PEROXIDASE

1962 ◽  
Vol 40 (4) ◽  
pp. 459-469 ◽  
Author(s):  
P. H. Jellinck ◽  
Louise Irwin
Keyword(s):  
Amino Acids ◽  
Hydrogen Peroxide ◽  
Amino Acid ◽  
Serum Albumin ◽  
Oxidase Activity ◽  
Water Soluble ◽  
The Other ◽  
Aerobic Incubation ◽  
Nitrogenous Compounds ◽  
Initial Generation

Aerobic incubation of estrone-16-C14with peroxidase in the presence of serum albumin and other proteins resulted in the formation of water-soluble, ether-insoluble metabolites in high percentage yields. Similar products were formed when protein was replaced by cysteine or tryptophan but none of the other amino acids tested had any effect. The evidence points to an initial generation of hydrogen peroxide from these nitrogenous compounds by the enzyme acting as an aerobic oxidase, and the subsequent peroxidation of estrone to highly reactive products. These then combine with the protein or amino acid or else undergo alternative reactions. A strong chemical bond is formed with albumin and attempts to release the estrone metabolites from it were unsuccessful. Uterine homogenates from estrogen-treated rats showing high DPNH oxidase activity contained no "peroxidase" as measured by the formation of water-soluble products from estrone in the presence of protein.

scholarly journals Dietary starch source influences in growing goats: the intestinal losses of endogenous nitrogen and amino acids

2010 ◽  
Vol 103 (12) ◽  
pp. 1755-1761
Author(s):  
Chuanshe Zhou ◽  
Zhiliang Tan ◽  
Yafei Pan ◽  
Shimin Liu ◽  
Shaoxun Tang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Latin Square ◽  
Amino Acid Profile ◽  
Water Soluble ◽  
The Other ◽  
Endogenous Amino Acids ◽  
Endogenous Protein ◽  
The Difference ◽  
Growing Goats ◽  
Dietary Starch

Four goats (20 (SD2·5) kg) fitted with ruminal, duodenal and ileal cannulae were used in a 4 × 4 Latin square design to estimate the effects of a dietary starch source on the duodenal and ileal flows of endogenous N (EN) and endogenous amino acids (EAA) in growing goats. Goats were fed total mixed rations containing four starch sources (mainly from maize (MR), wheat (WR), paddy (PR) and sorghum (SR) treatments). There were no significant (P>0·05) effects of the dietary starch source on the intestinal flows of EN and EAA. The duodenal flows of EN were 2·40, 2·39, 2·18 and 1·56 g/d for the MR, WR, PR and SR treatments, respectively, as determined by the difference method, and the duodenal flows of EAA were 10·76, 11·29, 10·95 and 10·96 g/d by estimation with the amino acid profile method. The flows of EN and EAA at the ileum were 1·17, 1·12, 1·01, 0·70 and 4·87, 4·95, 4·94, 4·99 g/d, respectively, as estimated by the water-soluble method. The average intestinal reabsorption of EN and EAA was 57·5 %, and the endogenous Leu by the MR treatment was significantly (P < 0·05) lower than that of the other three treatments. The present results indicate that losses of endogenous protein in the intestine were not affected by the dietary starch source.

scholarly journals DL-Piperidinium-2-carboxylate bis(hydrogen peroxide): unusual hydrogen-bonded peroxide chains

2020 ◽  
Vol 76 (8) ◽  
pp. 1331-1335 ◽  
Author(s):  
Mger A. Navasardyan ◽  
Dmitry A. Grishanov ◽  
Petr V. Prikhodchenko ◽  
Andrei V. Churakov
Keyword(s):  
Amino Acids ◽  
Hydrogen Peroxide ◽  
The Other ◽  
Molar Ratio ◽  
Acid Molecule ◽  
Asymmetric Unit ◽  
Compound C ◽  
Pipecolinic Acid ◽  
Peroxide Molecule ◽  
Hydrogen Bonded

The title compound, C6H11NO2·2H2O2, is the richest (by molar ratio) in hydrogen peroxide among the peroxosolvates of aliphatic α-amino acids. The asymmetric unit contains a zwitterionic pipecolinic acid molecule and two hydrogen peroxide molecules. The two crystallographically independent hydrogen peroxide molecules form a different number of hydrogen bonds: one forms two as donor and two as acceptor ([2,2] mode) and the other forms two as donor and one as acceptor ([2,1] mode). The latter hydrogen peroxide molecule forms infinite hydrogen-bonded hydroperoxo chains running along the c-axis direction, which is unusual for aliphatic α-amino acid peroxosolvates.

Understanding the risks and rewards of using 50% vs. 10% strength peroxide in pulp bleach plants

TAPPI Journal ◽  
2018 ◽  
Vol 17 (11) ◽  
pp. 601-607
Author(s):  
Alan Rudie ◽  
Peter Hart
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Rate ◽  
The Other ◽  
Mechanical Pulp ◽  
Engineering Controls ◽  
Point Of Use ◽  
Process Failure

The use of 50% concentration and 10% concentration hydrogen peroxide were evaluated for chemical and mechanical pulp bleach plants at storage and at point of use. Several dangerous occurrences have been documented when the supply of 50% peroxide going into the pulping process was not stopped during a process failure. Startup conditions and leaking block valves during maintenance outages have also contributed to explosions. Although hazardous events have occurred, 50% peroxide can be stored safely with proper precautions and engineering controls. For point of use in a chemical bleach plant, it is recommended to dilute the peroxide to 10% prior to application, because risk does not outweigh the benefit. For point of use in a mechanical bleach plant, it is recommended to use 50% peroxide going into a bleach liquor mixing system that includes the other chemicals used to maintain the brightening reaction rate. When 50% peroxide is used, it is critical that proper engineering controls are used to mitigate any risks.

Neurotoxicity and Neuroprotective Effects of Polyimides (PI) and Polyphenylenevinylene (PPV) against Hydrogen Peroxide (H2O2)

2011 ◽  
Vol 8 (2) ◽  
pp. 33
Author(s):  
Norfaezah Mazalan ◽  
Mazatulikhma Mat Zain ◽  
Nor Saliyana Jumali ◽  
Norhanim Mohalid ◽  
Zurina Shaameri ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Drug Delivery Systems ◽  
Neuronal Cells ◽  
Water Soluble ◽  
Brain Delivery ◽  
Specific Therapy ◽  
Neuroprotective Effects ◽  
Water Soluble Polymer ◽  
Site Specific ◽  
Novel Drugs

Recently, research and development in the field of drug delivery systems (DDS) facilitating site-specific therapy has reached significant progression. DDS based on polymer micelles, coated micro- and nanoparticles, and various prodrug systems including water-soluble polymer have been prepared and extensively studied as novel drugs designed for cancer chemotherapy and brain delivery. Since polymers are going to be used in human, this study has the interest of testing two types of polymer, polyimides (PI) and polyphenylenevinylene (PPV) on neuronal cells. The objective of this study was to determine the possible neurotoxicity and potential neuroprotective effects of PI and PPV towards SH-SY5Y neuronal cells challenged by hydrogen peroxide (H2O2) as an oxidant. Cells were pretreated with either PI or PPV for 1 hour followed by incubation for 24 hour with 100 µM of H2O2. MTS assay was used to assess cell viability. Results show that PI and PPV are not harmful within the concentration up to 10 µM and 100 µM, respectively. However, PI and PPV do not protect neuronal cells against toxicity induced by H2O2 or further up the cell death.

Pengaruh Luka Iris Pada Tikus Dengan Paparan Hidrogen Peroxida 3% terhadap Epitelisasi dan Pembentukan Eksudat pada Permukaan Epitel Kulit.

2020 ◽  
Vol 17 (2) ◽  
pp. 172
Author(s):  
HARMAN AGUSAPUTRA ◽  
MARIA SUGENG ◽  
AYLY SOEKAMTO ◽  
ATIK WULANDARI
Keyword(s):  
Hydrogen Peroxide ◽  
Wound Healing ◽  
The Other ◽  
Delayed Wound Healing ◽  
Peroxide Group ◽  
Hemostatic Effect ◽  
Significant Difference ◽  
Negative Effect ◽  
Wound Healing Effect ◽  
Epithelial Growth

<p><strong>Abstract</strong></p><p><strong>Background:</strong> Hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) as antiseptic has been used frequently to clean woundsin in hospitals and clinics. Hydrogen peroxide has the effectof strong oxidative that can kill pathogens. It can clean up debris and necrotic tissuesin wounds. Hydrogen peroxidealso has hemostatic effect that can help to stop bleeding. Besides antiseptic effects, hydrogen peroxide i s suspected of having negative effect in wound healing. Hydrogen peroxide presumably could cause delayed wound healing by exudate formation and delayed epithelial growth.</p><p><strong>Method</strong>: This study was conducted in the laboratory using 48 white mice that were divided into 2 groups. All the mice were purposely wounded. Afterwards in one group the wounds were clean up using hydrogen peroxide, while in the other group without hydrogen peroxide as control. The wounds of both groups were observed on day 1, day 3 and day 7. On day 1 and day 3, both groups did not show significant difference.</p><p><strong>R</strong><strong>esult</strong> : on day 7 showed that the wound healing in hydrogen peroxide group were delayed. Fifty percent of them had the formation of exudate and 62.5% of them showed delayed epithelial growth.</p><p><strong>Conclusion </strong>: This study could show hydrogen peroxide as wound antiseptic has delayed wound healing effect.</p><p><strong>Keyword</strong>: hydrogen peroxide, wound healing</p>

Antimicrobial Effect of 940 nm Diode Laser based on Photolysis of Hydrogen Peroxide in the Treatment of Periodontal Disease

2018 ◽  
Vol 69 (8) ◽  
pp. 2081-2088 ◽  
Author(s):  
Alin Alexandru Odor ◽  
Edwin Sever Bechir ◽  
Deborah Violant ◽  
Victoria Badea
Keyword(s):  
Hydrogen Peroxide ◽  
Laser Therapy ◽  
Diode Laser ◽  
Antimicrobial Effect ◽  
The Other ◽  
Control Group ◽  
Group 4 ◽  
Periodontal Bacteria ◽  
Severe Periodontitis ◽  
Before And After

Moderate and severe periodontitis represents a challenge in the non-surgical periodontal therapy. Due to the lack of evidence regarding the antimicrobial effectiveness of 940 nm diode laser in periodontal treatment, this study aimed to evaluate the antimicrobial effect of hydrogen peroxide (H2O2) photolysis performed with 940 nm diode laser in the treatment of moderate and severe periodontitis. Twenty-five patients with 100 teeth were selected for this pilot study. The test teeth were randomly assigned to one of the four treatment groups: Group 1: scaling and root planning (SRP) (control group); and the following experimental groups: Group 2: H2O2; Group 3: 940 nm diode laser therapy; Group 4: 940 nm diode laser therapy and H2O2. Clinical examinations, like probing depth (PD), clinical attachment level (CAL) and bleeding on probing (BOP) were performed before and after the treatment. The microbiological evaluation, effectuated before and after the treatment, included nine periodontal bacteria species and investigated by means of real-time PCR assay. The clinical and bacterial differences in the tested groups, was assessed between control group and the other three experimental groups, as well as between the experimental groups. The total bacteria load was reduced for all four studied groups. Group 4 (diode laser + H2O2) showed significant bacterial reduction of the major periodontal bacteria like Pg., Tf., Td., Pi., Pm., Fn (p[0.001) than the other 3 groups (p]0.001). Also the periodontal clinical parameters, like PD, CAL and BOP showed a significant reduction after the photolysis of H2O2 with the 940 nm diode laser (p[0.001). Differences between tested groups showed a significant beneficial results in regard to Group 4.It is suggested that the photoactivation of H2O2 with the 940 nm diode laser can be used successfully in adjunctive to the non-surgical periodontal treatment as a bactericidal tool.

An ESR study of the peroxidase reaction catalyzed by human methaemoglobin and methaemoglobin-haptoglobin complex

1991 ◽  
Vol 56 (4) ◽  
pp. 923-932
Author(s):  
Jana Stejskalová ◽  
Pavel Stopka ◽  
Zdeněk Pavlíček
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Amino Acid ◽  
Peroxidase Activity ◽  
Amino Acid Analysis ◽  
Superoxide Radical ◽  
Esr Spectra ◽  
The Other ◽  
Delocalized Electron

The ESR spectra of peroxidase systems of methaemoglobin-ascorbic acid-hydrogen peroxide and methaemoglobin-haptoglobin complex-ascorbic acid-hydrogen peroxide have been measured in the acetate buffer of pH 4.5. For the system with methaemoglobin an asymmetrical signal with g ~ 2 has been observed which is interpreted as the perpendicular region of anisotropic spectrum of superoxide radical. On the other hand, for the system with methaemoglobin-haptoglobin complex the observed signal with g ~ 2 is symmetrical and is interpreted as a signal of delocalized electron. After realization of three repeatedly induced peroxidase processes the ESR signal of the perpendicular part of anisotropic spectrum of superoxide radical is distinctly diminished, whereas the signal of delocalized electron remains practically unchanged. An amino acid analysis of methaemoglobin along with results of the ESR measurements make it possible to derive a hypothesis about the role of haptoglobin in increasing of the peroxidase activity of methaemoglobin.

The effect of cation concentration on the nitrogen splitting constant of nitroxide free radicals

1990 ◽  
Vol 55 (10) ◽  
pp. 2377-2380
Author(s):  
Hamza A. Hussain
Keyword(s):  
Hydrogen Peroxide ◽  
Hydrogen Bonding ◽  
Free Radicals ◽  
Esr Spectroscopy ◽  
The Other ◽  
Tetraethylammonium Bromide ◽  
Splitting Constant ◽  
The One ◽  
Positively Charged ◽  
Two Equilibria

Nitroxide free radicals prepared from diethylamine, piperidine and pyrrolidine by oxidation with hydrogen peroxide were studied by ESR spectroscopy. The changes in the 14N splitting constant (aN) caused by the addition of KBr or tetraethylammonium bromide were measured in dependence on the concentration of the ions. For diethylamine nitroxide and piperidine nitroxide, the results are discussed in terms of two equilibria: the one, involving the anion, is associated with a gain or loss of hydrogen bonds to the nitroxide oxygen atom, the other is associated with the formation of solvent shared units involving the cation, which results in changes in the hydrogen bonding strenght. The large increase in the aN value in the case of pyrrolidine nitroxide is explained in terms of an interaction from one side of the positively charged N atom; the increase in aN in the case of diethylamine and piperidine nitroxides is explained in terms of interactions with both sides of the positively charged N atom.

Sign in / Sign up

Export Citation Format

Share Document