Self-Organized Amphiphiles are Poor Hydroxyl Radical Scavengers in Fast Photochemical Oxidation of Proteins Experiments

ABSTRACTThe analysis of membrane protein topography using fast photochemical oxidation of protein (FPOP) has been reported in recent years, but still underrepresented in literature. Based on the hydroxyl radical reactivity of lipids and other amphiphiles, it is believed that the membrane environment acts as a hydroxyl radical scavenger decreasing effective hydroxyl radical doses and resulting in less observed oxidation of proteins. Here, we investigated the effect of bulk hydroxyl radical scavenging in FPOP using both isolated cellular membranes as well as detergent micelles. We found no significant change in radical scavenging activity upon the addition of disrupted cellular membranes with the membrane concentration in the range of 0-25600 cell/μL using an inline radical dosimeter. We confirmed the non-scavenging nature of the membrane with the FPOP results of a soluble model protein in the presence of cell membranes, which showed no significant difference in oxidation with or without membranes. The use of detergents revealed that, while soluble detergent below the critical micelle concentration acts as a potent hydroxyl radical scavenger as expected, additional detergent has little to no hydroxyl radical scavenging effect once the critical micelle concentration is reached. These results suggest that any scavenging effect of membranes or organized amphiphilic membrane mimetics in FPOP experiments are not due to bulk hydroxyl radical scavenging, but may be due to a localized scavenging phenomenon.

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Radical Scavenging Activities of Novel Cationic Inulin Derivatives

Polymers ◽

10.3390/polym10121295 ◽

2018 ◽

Vol 10 (12) ◽

pp. 1295

Author(s):

Yuan Chen ◽

Yingqi Mi ◽

Jingjing Zhang ◽

Fang Dong ◽

Qing Li ◽

...

Keyword(s):

Hydroxyl Radical ◽

Hydroxyl Radicals ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Synthesis Process ◽

Scavenging Activity ◽

Scavenging Effect ◽

Radical Scavenging Effect ◽

Ft Ir

Many saccharides are attractive targets for biomaterial applications, due to their abundance, biocompatibility, and biodegradability. In this article, a synthesis process of 6-N-substituted cationic inulin derivatives, including 6-pyridyl-6-deoxyinulin bromide (PIL), 6-(2-amino-pyridyl)-6-deoxyinulin bromide (2APIL), 6-(3-amino-pyridyl)-6-deoxyinulin bromide (3APIL), 6-(4-amino-pyridyl)-6-deoxyinulin bromide (4APIL), 6-(2,3-diamino-pyridyl)-6-deoxyinulin bromide (2,3DAPIL), 6-(3,4-diamino-pyridyl)-6-deoxyinulin bromide (3,4DAPIL), and 6-(2,6-diamino-pyridyl)-6-deoxyinulin bromide (2,6DAPIL) was described. The C6-OH of inulin was first activated by PPh3/N-bromosuccinimide (NBS) bromination. Then, pyridine and different kinds of amino-pyridine groups (different position and different numbers of amino) were grafted onto inulin, respectively, via nucleophilic substitution. Then, we confirmed their structure by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy. After this, their radical scavenging activities against hydroxyl radical and diphenylpicryl phenylhydrazine (DPPH) radical were tested in vitro. Each derivative showed a distinct improvement in radical scavenging activity when compared to inulin. The hydroxyl-radical scavenging effect decreased in the following order: 3APIL > PIL > 3,4DAPIL > 4APIL > 2,3DAPIL > 2,6DAPIL > 2APIL. Amongst them, 3APIL revealed the most powerful scavenging effect on hydroxyl radicals, as well as DPPH radicals. At 1.6 mg/mL, it could completely eliminate hydroxyl radicals and could clear 65% of DPPH radicals. The results also showed that the steric hindrance effect and the substitute position of the amino group had an effect on the radical scavenging activity. Moreover, the application prospects of inulin derivatives as natural antioxidant biomaterials are scientifically proven in this paper.

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Hydroxyl radical scavenging properties of cyclitols

Proceedings of the Royal Society of Edinburgh Section B Biological Sciences ◽

10.1017/s0269727000014226 ◽

1994 ◽

Vol 102 ◽

pp. 269-272 ◽

Cited By ~ 27

Author(s):

Birgit Orthen ◽

Marianne Popp ◽

Nicholas Smirnoff

Keyword(s):

Hydroxyl Radical ◽

Oxygen Free Radicals ◽

Radical Scavenging ◽

Compatible Solutes ◽

Plant Cells ◽

Radical Scavenger ◽

Low Molecular Weight ◽

General Role ◽

Hydroxyl Radical Scavenger ◽

Radical Scavenging Properties

Cyclitols are low molecular weight substances which accumulate in plant cells in response to various environmental stress situations, for example drought (Ford 1984), salinity (Gorham et al. 1984), low temperature (Richter et al. 1990).Apart from their more general role in osmotic adjustment, only in the case of salt stress is their mode of function well understood. Cyclitols (e.g. pinitol) accumulate when plants are exposed to increasing salt concentration (Paul & Cockburn 1989) and act as compatible solutes (Sommer et al. 1990) as defined by Brown & Simpson (1972).The significance of cyclitol accumulation in stress adaptation of plants to drought and cold still remains uncertain. However, it is generally accepted that drought and cold as well as several other stress situations lead to an enhanced generation of oxygen free radicals (Elstner 1990; Smirnoff & Colombe 1988), including the hydroxyl radical as the most harmful one. The report by Smirnoff & Cumbes (1989) that myo-inositol is an effective hydroxyl radical scavenger prompted us to test other naturally-occuring cyclitols like pinitol, quebrachitol, 1-D-1-O-methyl-muco-inositol, ononitol and quercitol for their ability to scavenge hydroxyl radicals.

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Hydroxycinnamic Acid Antioxidants: An Electrochemical Overview

BioMed Research International ◽

10.1155/2013/251754 ◽

2013 ◽

Vol 2013 ◽

pp. 1-11 ◽

Cited By ~ 85

Author(s):

José Teixeira ◽

Alexandra Gaspar ◽

E. Manuela Garrido ◽

Jorge Garrido ◽

Fernanda Borges

Keyword(s):

Rational Design ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Phenoxyl Radical ◽

Free Radical Scavenger ◽

Hydroxycinnamic Acid ◽

Hydroxycinnamic Acids ◽

Radical Scavenger ◽

Redox Potentials ◽

Structure Property

Hydroxycinnamic acids (such as ferulic, caffeic, sinapic, andp-coumaric acids) are a group of compounds highly abundant in food that may account for about one-third of the phenolic compounds in our diet. Hydroxycinnamic acids have gained an increasing interest in health because they are known to be potent antioxidants. These compounds have been described as chain-breaking antioxidants acting through radical scavenging activity, that is related to their hydrogen or electron donating capacity and to the ability to delocalize/stabilize the resulting phenoxyl radical within their structure. The free radical scavenger ability of antioxidants can be predicted from standard one-electron potentials. Thus, voltammetric methods have often been applied to characterize a diversity of natural and synthetic antioxidants essentially to get an insight into their mechanism and also as an important tool for the rational design of new and potent antioxidants. The structure-property-activity relationships (SPARs) correlations already established for this type of compounds suggest that redox potentials could be considered a good measure of antioxidant activity and an accurate guideline on the drug discovery and development process. Due to its magnitude in the antioxidant field, the electrochemistry of hydroxycinnamic acid-based antioxidants is reviewed highlighting the structure-property-activity relationships (SPARs) obtained so far.

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Alleviation of wood smoke-induced lung injury by tachykinin receptor antagonist and hydroxyl radical scavenger in guinea pigs

European Journal of Pharmacology ◽

10.1016/s0014-2999(01)01184-0 ◽

2001 ◽

Vol 425 (2) ◽

pp. 141-148 ◽

Cited By ~ 21

Author(s):

You Shuei Lin ◽

Ching-Yin Ho ◽

Gau-Jun Tang ◽

Yu Ru Kou

Keyword(s):

Lung Injury ◽

Hydroxyl Radical ◽

Receptor Antagonist ◽

Guinea Pigs ◽

Wood Smoke ◽

Radical Scavenger ◽

Tachykinin Receptor ◽

Hydroxyl Radical Scavenger

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Evidence suggesting a role for hydroxyl radical in glycerol-induced acute renal failure

AJP Renal Physiology ◽

10.1152/ajprenal.1988.255.3.f438 ◽

1988 ◽

Vol 255 (3) ◽

pp. F438-F443 ◽

Cited By ~ 11

Author(s):

S. V. Shah ◽

P. D. Walker

Keyword(s):

Renal Failure ◽

Acute Renal Failure ◽

Hydroxyl Radical ◽

Tissue Injury ◽

Iron Chelator ◽

Radical Scavenger ◽

Reactive Oxygen Metabolites ◽

Protective Effects ◽

Hydroxyl Radical Scavenger ◽

Hydroxyl Radical Scavengers

Reactive oxygen metabolites, in particular hydroxyl radical, have been shown to be important mediators of tissue injury in several models of acute renal failure. The aim of the present study was to examine the role of hydroxyl radical in glycerol-induced acute renal failure, a model for myoglobinuric renal injury. Rats injected with glycerol alone (8 mg/kg im following dehydration for 24 h) developed significant renal failure compared with dehydrated controls. Rats treated with glycerol and a hydroxyl radical scavenger, dimethylthiourea (DMTU), had significantly lower blood urea nitrogen (BUN) and creatinine. In contrast, urea, which is chemically similar to DMTU but is not a hydroxyl radical scavenger, provided no protection. In addition, DMTU prevented the glycerol-induced rise in renal cortical malondialdehyde content (a measure of lipid peroxidation that serves as a marker of free radical-mediated tissue injury). A second hydroxyl radical scavenger, sodium benzoate, had a similar protective effect on renal function (as measured by both BUN and creatinine). Because the generation of hydroxyl radical in biological systems requires the presence of a trace metal such as iron, we also examined the effect of the iron chelator, deferoxamine on glycerol-induced renal failure. Deferoxamine was also protective. The interventional agents were also associated with a marked reduction in histological evidence of renal damage. The protective effects of two hydroxyl radical scavengers as well as an iron chelator implicate a role for hydroxyl radical in glycerol-induced acute renal failure.

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Pharmacological studies of Mangifera indica leaf extract

World Journal of Biology Pharmacy and Health Sciences ◽

10.30574/wjbphs.2021.7.3.0100 ◽

2021 ◽

Vol 7 (3) ◽

pp. 073-079

Author(s):

Agrawal RC

Keyword(s):

Hydroxyl Radical ◽

Radical Scavenging Activity ◽

Mangifera Indica ◽

Radical Scavenging ◽

Antibacterial Activities ◽

Positive Control ◽

Screening Methods ◽

Phytochemical Screening ◽

Test Organisms ◽

Almost All

The present study was undertaken to explore the phytochemical screening, anti-bacterial and anti-oxidant activities of the hydro-methanolic leaves extract of Mangifera indica using standard screening methods such as disc diffusion and DPPH methods. In phytochemical screening, Mangifera indicaextract showed presence of secondary metabolites such as carbohydrate, phenols, tanins and proteins whereas Saponins were absent. It also showed antibacterial activities against almost all the test organisms. The extracts possessed potent hydroxyl radical scavenging activity against the positive control standard Ascorbic acid. Results denote the presence of hydroxyl radical scavenging principles in the extracts.

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Effects of solvent extraction system on antioxidant activity of Lamium purpureum L.

Hemijska industrija ◽

10.2298/hemind160518047g ◽

2017 ◽

Vol 71 (5) ◽

pp. 361-370

Author(s):

Slavica Grujic ◽

Ana Dzamic ◽

Violeta Mitic ◽

Vesna Stankov-Jovanovic ◽

P.D. Marin ◽

...

Keyword(s):

Antioxidant Activity ◽

Methanol Extract ◽

Phenolic Content ◽

Radical Scavenging Activity ◽

Antioxidant Properties ◽

Radical Scavenging ◽

Reducing Power ◽

Total Phenolic ◽

Radical Scavenger ◽

Scavenging Activity

Antioxidant and free radical scavenging activity of methanol, ethanol, ethyl acetate and chloroform extracts of aerial parts of Lamium purpureum L. was determined by DPPH, ABTS, FRAP and TRP assays. Contents of flavonoids and phenols were also investigated. The total phenolic content in the extracts, determined using Folin?Ciocalteu assay, ranged between 8.57 to 128.00 mg GAE/g d.e. while concentrations of flavonoids in the extracts varied from 24.20 to 39.80 mg QuE/g d.e. The highest phenolic content was found in methanol extract (128.00 mg GAE/g d.e.). The highest content of total flavonoids was identified in the methanol extract (39.80 mg QuE/g d.e.) and the lowest was in the chloroform (24.30 mg QuE/g d.e.). DPPH scavenging of the extracts was determined and obtained IC50 values ranged from 0.12 to 3.12 mg/mL of solution. The values of ABTS radical scavenging activity ranged from 0.35 to 1.80 mg AA/g. The highest ABTS antiradical activity was registered for methanol extract. The FRAP value was found within the range 0.08 to 1.04 ?mol Fe/mg. The best radical scavenger was methanol (1.04 ?mol Fe/mg). In reducing power assay different extracts of L. purpureum showed increasing of activity with increased concentration, and all extracts possessed substantial dose dependent antioxidant activity. The best reducing capacity was obtained with methanol extract of L. purpureum (0.0132 mg AA/mL). The results in this study confirmed that L. purpureum possesses moderate antioxidant properties.

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Some Special Properties of Fermented Products with Cabbage Origin: Pickled Cabbage, Sauerkraut and Kimchi

Turkish Journal of Agriculture - Food Science and Technology ◽

10.24925/turjaf.v7i3.490-497.2350 ◽

2019 ◽

Vol 7 (3) ◽

pp. 490

Author(s):

Ceren Özer ◽

Hatice Kalkan Yıldırım

Keyword(s):

Ascorbic Acid ◽

Antioxidant Defense ◽

Phenolic Content ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Antioxidant Defense System ◽

Total Phenolic ◽

Acid Fermentation ◽

Scavenging Effect ◽

Fermented Products

Consumption of fermented products rich in antioxidants, anti-inflammatory, anti-diabetes, anti-obesity and anti-carcinogenic compounds is growing into a key strategy to fortify antioxidant defense system. Cabbage products produced by lactic-acid fermentation are chosen via their special microbiota. Considering these special medical properties of fermented-cabbage products as pickled cabbage, sauerkraut and kimchi were produced and evaluated. The data demonstrated that pickled cabbage (109.89±4.74 mg ascorbic acid/100 g d.w.) and its brine (208.14±17.29 mg ascorbic acid/100 g d.w.) exhibited the highest vitamin C content, followed by kimchi (77.42±2.87 mg ascorbic acid/100 g d.w.). The highest total phenolic content was detected in kimchi and sauerkraut with 869.64±70.16 and 438.257±25.05 mg gallic acid equivalents/100 g fresh weight (f.w.), respectively. 50% of the scavenging effect (EC50) values of free radical scavenging activity (DPPH) in kimchi 14.6 mg/ml, followed by sauerkraut (15.52 mg/ml) and pickled cabbage (18.88 mg/ml). Results demonstrated that fermented cabbage products have a great potential with content of bioactive compounds, high antioxidant features promising high beneficial impacts.

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