Scavenging effect of melatonin on hydroxyl radicals generated by alloxan

In the present work, the treatment of a mixture of six emerging pollutants (acetamiprid, acetaminophen, caffeine, amoxicillin, clofibric acid and carbamazepine) by means of photo-Fenton process has been studied, using simulated sunlight as an irradiation source. Removal of these pollutants has been investigated in three different aqueous matrices distinguished by the amount of chlorides (distilled water, 1 g L−1 of NaCl and 30 g L−1 of NaCl) at a pH of 2.8 and 5.0. Interestingly, the presence of 1 g L−1 was able to slightly accelerate the pollutants removal at pH = 5, although the reverse was true at pH = 2.8. This is attributed to the pH-dependent interference of chlorides on photo-Fenton process, that is more acute in an acidic medium. As a matter of fact, the fastest reaction was obtained at pH = 3.5, in agreement with literature results. Monitoring of hydrogen peroxide consumption and iron in solution indicates that interference with chlorides is due to changes in the interaction between iron and the peroxide, rather than a scavenging effect of chloride for hydroxyl radicals. Experiments were also carried out with real seawater and showed higher inhibition than in the NaCl experiments, probably due to the effect of different dissolved salts present in natural water.

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Separation and Properties of Polysaccharides from Asparagus (Officinalis L) Old Stalks

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.361-363.789 ◽

2011 ◽

Vol 361-363 ◽

pp. 789-793 ◽

Cited By ~ 1

Author(s):

Jia Song ◽

Yue Ma ◽

Chao Zhang ◽

Xiao Yan Zhao ◽

Hai Feng Qian

Keyword(s):

Molecular Weight ◽

Antioxidant Capacity ◽

Hydroxyl Radicals ◽

Average Molecular Weight ◽

Antioxidative Capacity ◽

Scavenging Effect ◽

Ethanol Precipitation

The polysaccharides of the asparagus old stalks was seperated by ethanol precipitation and ultrafiltration. The molecular weigh distribution and antioxidative capacity of the extracts of the alcohol precipitation(C-1), ultrafiltration retention(C-2), and ultrafiltration penetrates (C-3) were further evaluated. The polysaccharides yields of the C-1, C-2, and C-3 were 1.53, 1.21, and 0.71%, respectively. The weigh average molecular weight of C-1, C-2, and C-3 were 163900, 135880, and 61063 Da, respectively. C-2 showed the strongest antioxidant capacity in all extracts by the scavenging effect on DPPH, superoxide and hydroxyl radicals. Therefore, the ultrafiltration was an alternative to separate the polysaccharides from the asparagus old stalks and kept their antioxidatant capacity.

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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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Structural Determination and Antioxidant Activity of a Polysaccharide from the Fruiting Bodies of Cultured Cordyceps sinensis

The American Journal of Chinese Medicine ◽

10.1142/s0192415x09007387 ◽

2009 ◽

Vol 37 (05) ◽

pp. 977-989 ◽

Cited By ~ 32

Author(s):

Ying Wang ◽

Min Wang ◽

Yun Ling ◽

Weiqiang Fan ◽

Yufeng Wang ◽

...

Keyword(s):

Antioxidant Activity ◽

Hydroxyl Radicals ◽

Average Molecular Weight ◽

Periodate Oxidation ◽

Reducing Power ◽

Water Soluble ◽

Hot Water ◽

Partial Acid Hydrolysis ◽

Scavenging Effect ◽

Chelating Activity

A water-soluble polysaccharide named CPS1 had been isolated from C. sinensis mycelium by hot water extraction, ethanol precipitation, anion-exchange, and gel-permeation chromatography. UV spectra, FTIR spectra, partial acid hydrolysis, PMP precolumn derivation, periodate oxidation and Smith degradation studies were conducted to elucidate its structure. The results indicated that CPS1 was a glucomannogalactan with the monosaccharide composition of glucose: mannose: galactose = 2.8: 2.9: 1. The total carbohydrate content of CPS1 was 99.0%. The weight-average molecular weight was 8.1 × 103 Da . The results predicted (1 → 2) and (1 → 4)-linkage of mannose, (1 → 3)-linkage of galactose, (1 → ) and (1 → 3, 6)-linkage of glucose composed the backbone of CPS1. CPS1 was also evaluated for its antioxidant activity in vitro, including scavenging effects on the hydroxyl radicals, the reducing power, Fe2+ -chelating activity, scavenging effect on superoxide radicals, as well as the inhibition of hydrogen peroxide induced haemolysis. CPS1 showed a high antioxidant effect, especially scavenging effect of hydroxyl radicals, the reducing power and Fe2+ -chelating activity. The results provide scientific support for the antioxidant activity and indicated a connection between antioxidant activity and reparation of renal failure.

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Effect of Lu-Duo-Wei on Scavenging Superoxide and Hydroxyl Radicals in vitro

The American Journal of Chinese Medicine ◽

10.1142/s0192415x98000208 ◽

1998 ◽

Vol 26 (02) ◽

pp. 153-158 ◽

Cited By ~ 8

Author(s):

Yun-Zhong Fang ◽

Cun-Pu Sun ◽

Xiao-Hua Tian ◽

Jian-Ho Cong

Keyword(s):

Electron Spin Resonance ◽

Green Tea ◽

Hydroxyl Radicals ◽

Superoxide Radical ◽

Spin Trapping ◽

Synergistic Action ◽

Tea Polyphenol ◽

Scavenging Effect ◽

Spin Resonance

Irradiation of a riboflavin-containing system by ultraviolet light was used to produce superoxide radical (•O2-). Hydroxyl radical (•OH) was generated by the system of Fe (II)-H2O2. Using electron spin resonance and spin trapping techniques, the effect of Lu-Duo-Wei, a capsule consisting extracts of green tea, Fructus Lycii and Semen Ziziphi Spinosae, on scavenging •O2- and •OH was observed. The results showed that the efficiency of scavenging •O2- and •OH by Lu-Duo-Wei was much higher than that by tea polyphenol alone. It is suggested that the synergistic action of tea polypheno1 and other components are responsible for the scavenging effect of Lu-Duo-Wei on •O2- and •OH.

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