Superoxide free radical spin‐lattice relaxivity: A quench‐assisted MR study

2021 ◽  
Vol 86 (2) ◽  
pp. 1058-1066
Author(s):  
Martin J. MacKinnon ◽  
Bruce A. Berkowitz ◽  
Yen‐Yu Ian Shih
Keyword(s):  
Free Radical ◽  
Spin Lattice ◽  
Superoxide Free Radical ◽  
Mr Study

Antioxidant Activity of Silk Fibroin Peptide Hydrolyzed by Pancreatin

2014 ◽  
Vol 1081 ◽  
pp. 110-114 ◽  
Author(s):  
Zhen Zhu ◽  
Hua Yin ◽  
Yan An
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Nitrogen Content ◽  
Silk Fibroin ◽  
Radical Scavenging ◽  
Amino Nitrogen ◽  
Free Radical Scavenging ◽  
Hydrolysis Process ◽  
Superoxide Free Radical ◽  
Hydrolysis Of

This research adopts the pancreatin hydrolysis of silk fibroin active peptide, evaluate the antioxidant activity of hydrolysates. In the process of hydrolysis of silk fibroin, by measuring the amino nitrogen content of neutral formaldehyde titration method. Find the amino nitrogen content gradually stabilized at around 0.37g/L, and superoxide free radical scavenging rate changing with time fluctuation trend, superoxide free radical scavenging rate to a maximum of 65.03% at 220min.The use of silk fibroin hydrolysis process optimization,reaction time 160min, enzyme concentration4% , substrate concentration 20mg/ml, pH 8, temperature 38°C. The hydrolysis process under the hydrolysate on superoxide radical scavenging rate of 72.73%. The scavenging rate of hydroxyl radical is 47.24%. Red blood cell hemolysis induced by H2O2 inhibition rate was 24.30%.

Superoxide free radical and intracellular calcium mediate Aβ1–42 induced endothelial toxicity

1997 ◽  
Vol 762 (1-2) ◽  
pp. 144-152 ◽  
Author(s):  
Zhiming Suo ◽  
Chunhong Fang ◽  
Fiona Crawford ◽  
Mike Mullan
Keyword(s):  
Free Radical ◽  
Intracellular Calcium ◽  
Superoxide Free Radical

Ethylene Formation by Isolated Chloroplast Lamellae in the Dark

1975 ◽  
Vol 30 (1-2) ◽  
pp. 58-63 ◽  
Author(s):  
Erich Elstner ◽  
Jörg Konze
Keyword(s):  
Heat Treatment ◽  
Superoxide Dismutase ◽  
Free Radical ◽  
Sulfonic Acid ◽  
Ethylene Biosynthesis ◽  
Reactive Species ◽  
Oh Radical ◽  
Ethylene Formation ◽  
Ferredoxin Reductase ◽  
Superoxide Free Radical

Abstract Ethylene Biosynthesis, Chloroplasts, Superoxide Free Radical Isolated chloroplast lamellae from spinach produce ethylene in the dark from methylmercapto-propanal (MMP) or from 2-keto-4-methyl-mercaptobutyrate (KMB) only in the presence of both NADPH and ferredoxin. Anthraquinone-2-sulfonic acid can substitute for ferredoxin. Catalase, superoxide dismutase, ethanol and ascorbate are inhibitors of NADPH-dependent ethylene forma­ tion. Isolated NADP-ferredoxin reductase in the presence of NADPH, ferredoxin and an oxygen reducing factor (ORF, isolated by heat-treatment of chloroplast lamellae) catalyzes ethylene formation from the above substrates in the dark without chloroplast lamellae. From the results it is concluded that chloroplast lamellae in the dark can reduce oxygen monovalently at the expense of NADPH, with the production of the OH-radical as the reactive species responsible for ethylene formation from MMP of KMB.

5-07-39 Batroxobin scavenges superoxide free radical

1997 ◽  
Vol 150 ◽  
pp. S285
Author(s):  
Qizhuan Wu ◽  
Rinying Wang ◽  
Heqiou Bao
Keyword(s):  
Free Radical ◽  
Superoxide Free Radical

Participation of superoxide free radical and Mn2+ in sulfite oxidation

1978 ◽  
Vol 46 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Bunji Inouye ◽  
Mikiko Ikeda ◽  
Tatsuo Ishida ◽  
Masana Ogata ◽  
Jitsuo Akiyama ◽  
...  
Keyword(s):  
Free Radical ◽  
Sulfite Oxidation ◽  
Superoxide Free Radical

scholarly journals Influence of Temperature on Free Radical Generation in Propolis-Containing Ointments

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Paweł Olczyk ◽  
Pawel Ramos ◽  
Katarzyna Komosinska-Vassev ◽  
Lukasz Mencner ◽  
Krystyna Olczyk ◽  
...  
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Heating Temperature ◽  
Radical Formation ◽  
Paramagnetic Resonance ◽  
Influence Of Temperature ◽  
Spin Lattice ◽  
Influence Of Temperature On ◽  
Free Radical Formation ◽  
C 50

Free radicals thermally generated in the ointments containing propolis were studied by electron paramagnetic resonance (EPR) spectroscopy. The influence of temperature on the free radical concentration in the propolis ointments was examined. Two ointment samples with different contents of propolis (5 and 7%, resp.) heated at temperatures of 30°C, 40°C, 50°C, and 60°C, for 30 min., were tested. Homogeneously broadened EPR lines and fast spin-lattice interactions characterized all the tested samples. Free radicals concentrations in the propolis samples ranged from 1018 to 1020 spin/g and were found to grow in both propolis-containing ointments along with the increasing heating temperature. Free radical concentrations in the ointments containing 5% and 7% of propolis, respectively, heated at temperatures of 30°C, 40°C, and 50°C were only slightly different. Thermal treatment at the temperature of 60°C resulted in a considerably higher free radical formation in the sample containing 7% of propolis when related to the sample with 5% of that compound. The EPR examination indicated that the propolis ointments should not be stored at temperatures of 40°C, 50°C, and 60°C. Low free radical formation at the lowest tested temperatures pointed out that both examined propolis ointments may be safely stored up to the temperature of 30°C.

Reaotive oxygen generation by azomethine H: a new antimalarial drug

1995 ◽  
Vol 73 (8) ◽  
pp. 1189-1194 ◽  
Author(s):  
Ethel L. B. Novelli ◽  
Assunta M. M. Silva ◽  
Jose L.V.B. Novell F. ◽  
Paulo R. Curi
Keyword(s):  
Superoxide Dismutase ◽  
Free Radical ◽  
Superoxide Radical ◽  
Alanine Transaminase ◽  
Superoxide Dismutase Activity ◽  
Acid Solutions ◽  
Oxygen Generation ◽  
Hydrochloric Acid Solutions ◽  
Superoxide Free Radical ◽  
Important Intermediate

Superoxide radical [Formula: see text] is a free radical that may be involved in various toxic processes. Cu—Zn superoxide dismutase catalyzes the dismutation of the superoxide free radical and protects cells from oxidative damage. A rat bioassay validated for the identification of the toxic effects of azomethine H revealed increased serum activities of amylase, alanine transaminase, and alkaline phosphatase. The lipoperoxide and bilirubin concentrations were also increased in animals that received azomethine H (1 g/kg) from ascorbic or hydrochloric acid solutions. Azomethine H increased Cu–Zn superoxide dismutase activity. This elevation of Cu–Zn superoxide dismutase activity was highest on the 7th day and was at levels comparable with those of control rats from day 60 onwards. Superoxide is an important intermediate in the action and toxicity of azomethine H.Key words: azomethine H, superoxide radical, antimalarial, toxicity.

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