Monooxygenase-like oxidation of hydrocarbons by hydrogen peroxide catalyzed by manganese porphyrins and imidazole: selection of the best catalytic system and nature of the active oxygen species

1988 ◽  
Vol 110 (25) ◽  
pp. 8462-8470 ◽  
Author(s):  
P. Battioni ◽  
J. P. Renaud ◽  
J. F. Bartoli ◽  
M. Reina-Artiles ◽  
M. Fort ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic System ◽  
Active Oxygen Species ◽  
Active Oxygen ◽  
Oxygen Species ◽  
Manganese Porphyrins ◽  
Oxidation Of Hydrocarbons ◽  
Selection Of

Lung edema due to hydrogen peroxide is independent of cyclooxygenase products

1984 ◽  
Vol 56 (4) ◽  
pp. 900-905 ◽  
Author(s):  
O. Burghuber ◽  
M. M. Mathias ◽  
I. F. McMurtry ◽  
J. T. Reeves ◽  
N. F. Voelkel
Keyword(s):  
Hydrogen Peroxide ◽  
Glucose Oxidase ◽  
Direct Action ◽  
Active Oxygen Species ◽  
Active Oxygen ◽  
Lung Edema ◽  
Oxygen Species ◽  
Edema Formation ◽  
Prostaglandin Production ◽  
Prostaglandin F2 Alpha

Active oxygen species can cause lung injury. Although a direct action on endothelial cells is proposed, the possibility exists that they might cause injury via mediators. We considered that active oxygen species would stimulate the generation of cyclooxygenase metabolites, which then alter pulmonary vasoreactivity and cause edema. We chemically produced hydrogen peroxide by adding glucose oxidase to a plasma- and cell-free, but beta-D-glucose-containing, solution, which perfused isolated rat lungs. Addition of glucose oxidase to the perfusate caused a marked decrease in pulmonary vasoreactivity, accompanied by an increase in the concentrations of prostacyclin, thromboxane A2, and prostaglandin F2 alpha. Pretreatment with catalase, a specific scavenger of hydrogen peroxide, preserved pulmonary vasoreactivity, inhibited the increase of the concentration of the measured prostaglandins, and prevented edema formation. Indomethacin effectively blocked lung prostaglandin production but neither prevented the decrease in vasoreactivity nor inhibited edema formation. From these data we conclude that hydrogen peroxide impaired pulmonary vasoreactivity and subsequently caused edema. Despite the fact that hydrogen peroxide stimulated lung prostaglandin production, cyclooxygenase-derived products neither caused the decrease in vasoreactivity nor the development of edema.

scholarly journals 367 Scavenging Capacity of Active Oxygen Species in Blackberry

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 455E-455
Author(s):  
Shiow Y. Wang ◽  
Hongjun Jiao
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Singlet Oxygen ◽  
Hydroxyl Radicals ◽  
Fruit Juice ◽  
Active Oxygen Species ◽  
Active Oxygen ◽  
Oxygen Species ◽  
Scavenging Capacity ◽  
Β Carotene

The effect of blackberries (Rubus sp.) genotypes on antioxidant activities against superoxide radicals (O2–), hydrogen peroxide (H2O2), hydroxyl radicals (OH), and singlet oxygen (O,), was evaluated. The results were expressed as percent inhibition of active oxygen species production in the presence of fruit juice. The active oxygen radical absorbance capacity (ORAC) value referred to the net protection in the presence of fruit juice, and was expressed as micromoles of α-tocopherol, ascorbate, α-tocopherol, and β-carotene equivalents per 10 g of fresh weight for O2–, H2O2, OH, and O2, respectively. Among the different cultivars, juice of Hull' blackberry had the highest oxygen species, superoxide radicals (O2–), hydrogen peroxide (H2O2), hydroxyl radicals (OH), and singlet oxygen (O2,) scavenging capacity. Different antioxidants have their functional scavenging capacity against active oxygen species. There were interesting and marked differences among the different antioxidants in their abilities to inhibit the different active oxygen species. β-carotene had by far the highest scavenging activity against O2– but had absolutely no effect on H2O2. Ascorbic acid was the best at inhibiting H2O2 free radical activity. For OH, there was a wide range of scavenging capacities with α-tocopherol the highest and ascorbic acid the lowest. Glutathione had higher O2– scavenging capacity compared to the other antioxidants.

Catalytic Oxidation of Benzyl Alcohol to Benzaldehyde with Fe/Cu-Cross-Linked Montmorillonite

2011 ◽  
Vol 396-398 ◽  
pp. 1891-1894
Author(s):  
Xue Ju Zhang ◽  
He Song ◽  
Xiang Feng Guo ◽  
Li Hua Jia
Keyword(s):  
Hydrogen Peroxide ◽  
Liquid Phase ◽  
Benzyl Alcohol ◽  
Active Oxygen Species ◽  
Active Oxygen ◽  
Oxygen Species ◽  
Reaction Conditions ◽  
Oxidation Of Benzyl Alcohol ◽  
Excellent Activity ◽  
Phase Oxidation

The Fe/Cu-cross-linked montmorillonite catalysts were synthesized with Linan Na-Mont and characterized by BET, SEM, XRD. Liquid-phase oxidation of benzyl alcohol to benzaldehyde by hydrogen peroxide over Fe/Cu-PILC catalyst in the absence of solvent has been thoroughly investigated. The influence of reaction conditions has also been studied. The results show that Fe/Cu(100)-PILC has excellent activity and reusability in the process. The active oxygen species in the reaction is from the absorbed oxygen of Fe/Cu-PILC.

The Effect of Active Oxygen Species on the Cornea

1990 ◽  
Vol 48 (3) ◽  
pp. 242-243
Author(s):  
H. Nguyen ◽  
R. Carubelli ◽  
K.V. Chace ◽  
S.A. Graham ◽  
R. E. Nordquist
Keyword(s):  
Hydrogen Peroxide ◽  
Glucose Oxidase ◽  
Superoxide Anion ◽  
Tissue Injury ◽  
Vitamin A Deficiency ◽  
Active Oxygen Species ◽  
Active Oxygen ◽  
Oxygen Species ◽  
Corneal Ulceration ◽  
Corneal Melting

Corneal ulceration (“corneal melting”) can occur following various types of insults to the eye, e.g., alkaline or thermal burns, ocular laceration, rheumatoid arthritis, eye infections and vitamin A deficiency. A common link in this multiplicity of etiologic factors is the probable participation of active oxygen species (i.e., hydrogen peroxide, singlet oxygen and free radicals such as superoxide anion and hydroxyl radical). These compounds could play an important role in the pathogenesis of corneal melting since they have been implicated in numerous types of tissue injury. Therefore, we decided to investigate in rabbit cornea the effects of hydrogen peroxide (H2O2) and superoxide anion () generated in situ. Oxidation of endogenous corneal glucose by glucose oxidase was utilized for the generation of H2O2. A cationic preparation of glucose oxidase Aspergillus niger was obtained by amidation of its free carboxylic groups. This modification enhances retention of the enzyme through ionic interaction with polyanionic corneal proteoglycans. Intrastromal injections of 30-60 ug of this enzyme cause corneal ulceration in the rabbit.

Hydrogen peroxide is the most toxic oxygen species for Onchocerca cervicalis microfilariae

Parasitology ◽  
1990 ◽  
Vol 100 (3) ◽  
pp. 407-415 ◽  
Author(s):  
H. L. Callahan ◽  
R. K. Chouch ◽  
E. R. James
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Singlet Oxygen ◽  
Superoxide Radical ◽  
Active Oxygen Species ◽  
Active Oxygen ◽  
Oxygen Species ◽  
Low Levels ◽  
Scavenging Enzymes

SUMMARYThe toxicity of the active oxygen species hydrogen peroxide, superoxide radical, hydroxyl radical and singlet oxygen to microfilariae (mf) has been studied in vitro, using active oxygen-generating systems and scavengers/inhibitors. Mf viability was monitored by uptake of the radiolabel, [3H]2-deoxy-D-glouse. Hydrogen peroxide and singlet oxygen, but not superoxide radical or hydroxyl radical, are toxic for mf. Hydrogen peroxide was toxic for mf within 2 h at concentrations as low as 5 ¼, an amount eosinophils have been shown to release in vitro (Weiss et al. 1986). Catalase and thiourea, but not inactivated catalase, superoxide dismutase (SOD), singlet oxygen scavengers, or hydroxyl radical scavengers, protected mf. Mf have relatively high levels of endogenous SOD but no measurable glutathione peroxidase and low levels of catalase when compared with other parasites (Callahan, Crouch & James, 1988). The low levels of hydrogen peroxide-scavenging enzymes correlate well with mf sensitivity to hydrogen peroxide and the protective effect of exogenous catalase.

Characterization and functional properties of new everbearing strawberry (Fragaria x ananasa Duch.) cultivar, ‘Summertiara’ berries

2014 ◽  
Vol 4 (1) ◽  
pp. 1 ◽  
Author(s):  
Takeshi Nagai ◽  
Misuzu Tamai ◽  
Masato Sato ◽  
Yasuhiro Tanoue ◽  
Norihisa Kai ◽  
...  
Keyword(s):  
Vitamin C ◽  
Sensory Evaluation ◽  
Functional Properties ◽  
Active Oxygen Species ◽  
Active Oxygen ◽  
Antihypertensive Activity ◽  
Oxygen Species ◽  
Total Anthocyanins ◽  
Strawberry Cultivar ◽  
The Stability

Background: In recent years, a new everbearing strawberry cultivar, ‘Summertiara’ was cultivated to supply the strawberries in pre-harvest season from July to October in Japan. For highly research and development of processing of this cultivar, ‘Summertiara’ berries, the objective of this study was to characterize these berries, with relation to chemical parameters, total phenols, total flavonoids, total vitamin C, and total anthocyanins, and was to investigate the solubility and the stability of anthocyanins from the berries. Moreover, the functional properties such as antioxidative activity, active oxygen species scavenging activity, and antihypertensive activity were also evaluated.Methods: Chemical analysis, colour measurement, and sensory evaluation of new everbearing strawberry cultivar, ‘Summertiara’ berries were performed. Next, the solubility of anthocyanins from the berries and stability of these against pH, temperature, and an incandescent lighting were investigated. Moreover, functional properties of the extracts prepared from berries were elucidated using 5 different methods.Results: The contents of water, proteins, lipids, carbohydrates, and ash were the same as those of other cultivar berries. The sugar-acid ratio in the berries was low; these were acidulous. By sensory evaluation, the main factors were vivid red colour, aroma, and acidity. The berries were rich in phenols, flavonoids, vitamin C, and anthocyanins. The anthocyanins of the berries became unstable by heat treatment and light exposures such as visible rays. On the other hand, the extracts prepared from the berries showed the functionalities such as antioxidant activity, active oxygen species scavenging activities, and antihypertensive activity.  Conclusions: The strawberry cultivar, ‘Summertiara’ berries were the most suitable for processing ingredient of strawberry-derived products with superior health promoting functionalities.Keywords: Summertiara, everbearing strawberry cultivar, characterization, sensory evaluation, color and storage, functional property

Sign in / Sign up

Export Citation Format

Share Document