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.

Use of ESR to Investigate Formation of Free Radicals on Compounding Rubbers with Carbon Blacks

1978 ◽  
Vol 51 (1) ◽  
pp. 81-88 ◽  
Author(s):  
M. Jamroz˙ ◽  
K. Kozłowski ◽  
M. Sieniakowski ◽  
B. Jachym
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Radical Formation ◽  
Chemical Interactions ◽  
Carbon Blacks ◽  
Physicochemical State ◽  
Free Radical Formation ◽  
Open Question ◽  
Rubber Filler

Abstract The problem of rubber reinforcement is of great importance in rubber technology. Free radicals formed during mastication play an important role in the reinforcement of the rubber-filler system. The reinforcement of rubber systems is usually explained in terms of chemical interactions between rubber and filler; however, there are also opinions that the interactions are physical in nature. So far, the mechanism of reinforcement is an open question. Undoubtedly, reinforcement is influenced by free radicals formed during mastication and the physicochemical state of the surface of active fillers. The formation of free radicals during plasticization of rubbers has been already reported. Investigations by an ESR technique of free-radical formation during compounding of rubbers with various carbon blacks are described in the present paper.

scholarly journals Characterization of the Cicatrization Process in Diabetic Foot Ulcers Based on the Production of Reactive Oxygen Species

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Alberto López-Delis ◽  
Suélia de S. Rodrigues Fleury Rosa ◽  
Paulo Eduardo Narcizo de Souza ◽  
Marcella Lemos Brettas Carneiro ◽  
Mário Fabrício Fleury Rosa ◽  
...  
Keyword(s):  
Free Radical ◽  
Light Emitting Diode ◽  
Controlled Trial ◽  
Radical Formation ◽  
Lower Limbs ◽  
Paramagnetic Resonance ◽  
Healing Wound ◽  
Free Radical Formation ◽  
Group 2 ◽  
Circuit Group

The present study aims at evaluating the correlation between the free radical formation and the healing action of lower limbs’ ulcers in a randomized controlled trial with the use of an adhesive derived from natural latex associated with a light-emitting diode (LED) circuit. The sample consists of 15 participants with lower limb lesions divided into three groups: group 1 case (5 participants) received the proposed dressing system adhesive of the natural latex associated with the LED circuit; group 2 control (5 participants) received the dressings at home performed by nurses according to and established by the clinic of wounds (treated with calcium alginate or silver foam); and group 3 (5 participants) also received the dressing in their homes with the use of the dressing adhesive derived from the natural latex associated with the LED circuit. The collected data were analyzed qualitatively and quantitatively by electron paramagnetic resonance for determination of free radical formation. Kruskal-Wallis statistical test was used to evaluate the effect of treatment on the lower limb’s ulcer cicatrization process and its correlation with free radical. The results obtained corroborated the hypothesis about the reduction of the quantity of these molecules in the end of treatment related to the healing wound.

scholarly journals Hydrogen Peroxide Effects on Natural-Sourced Polysacchrides: Free Radical Formation/Production, Degradation Process, and Reaction Mechanism—A Critical Synopsis

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 699
Author(s):  
Chigozie E. Ofoedu ◽  
Lijun You ◽  
Chijioke M. Osuji ◽  
Jude O. Iwouno ◽  
Ngozi O. Kabuo ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Free Radicals ◽  
Free Radical ◽  
Structural Characteristics ◽  
Radical Formation ◽  
Research Attention ◽  
Natural Sources ◽  
Polysaccharide Degradation ◽  
Free Radical Formation

Numerous reactive oxygen species (ROS) entities exist, and hydrogen peroxide (H2O2) is very key among them as it is well known to possess a stable but poor reactivity capable of generating free radicals. Considered among reactive atoms, molecules, and compounds with electron-rich sites, free radicals emerging from metabolic reactions during cellular respirations can induce oxidative stress and cause cellular structure damage, resulting in diverse life-threatening diseases when produced in excess. Therefore, an antioxidant is needed to curb the overproduction of free radicals especially in biological systems (in vivo and in vitro). Despite the inherent properties limiting its bioactivities, polysaccharides from natural sources increasingly gain research attention given their position as a functional ingredient. Improving the functionality and bioactivity of polysaccharides have been established through degradation of their molecular integrity. In this critical synopsis; we articulate the effects of H2O2 on the degradation of polysaccharides from natural sources. Specifically, the synopsis focused on free radical formation/production, polysaccharide degradation processes with H2O2, the effects of polysaccharide degradation on the structural characteristics; physicochemical properties; and bioactivities; in addition to the antioxidant capability. The degradation mechanisms involving polysaccharide’s antioxidative property; with some examples and their respective sources are briefly summarised.

scholarly journals Influence of Spray-Drying and Room Temperature Storage on the Anti- and Prooxidant Properties of Fermented Juçara Pulp

2020 ◽  
Vol 58 (1) ◽  
pp. 29-37
Author(s):  
Karla Bigetti Guergoletto ◽  
Kamila Landucci Bonifácio ◽  
Décio Sabbatini Barbosa ◽  
Daniel Farinha Valezi ◽  
Aroldo Salviato ◽  
...  
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Antioxidant Capacity ◽  
Spray Drying ◽  
Room Temperature ◽  
Gum Arabic ◽  
Radical Formation ◽  
Total Phenolic ◽  
Free Radical Formation ◽  
And Storage

Many fruits and vegetables contain compounds with antioxidant properties, but the processing and storage conditions of the food industry may damage these beneficial compounds and produce free radicals that are associated with oxidative stress. This study aims to evaluate in vitro the antioxidant capacity and prooxidant effects of juçara pulp fermented with Lactobacillus reuteri or Lactobacillus plantarum before and after spray-drying with maltodextrin, gum arabic or gelatin and storage at 25 °C for 90 days. The antioxidant capacity was assessed by measuring the ability to scavenge reactive oxygen species (ROS) in the neutrophil respiratory burst and free radical 2,2-diphenyl-1-picryl-hydrazyl (DPPH), and by determining the total phenolic content. The prooxidant effects were analyzed as free radical formation measured by electronic paramagnetic resonance (EPR). Fermentation by both bacteria increased the antioxidant activity, while the spray-drying process decreased the content of phenolic compounds (65-85 %) and the DPPH scavenging ability, depending on the carrier usage. All of the samples inhibited ROS in the neutrophil burst, and the juçara pulp fermented by L. reuteri and dried with gum arabic exhibited the best performance. Spray-drying did not influence the intensity or type of free radicals detected by EPR. However, storage at room temperature decreased the antioxidant capacity and increased free radical formation.

Blue ‘turn-on’ fluorescent probes for the direct detection of free radicals and nitric oxide in Pseudomonas aeruginosa biofilms

2016 ◽  
Vol 14 (7) ◽  
pp. 2272-2281 ◽  
Author(s):  
Mina Barzegar Amiri Olia ◽  
Athanasios Zavras ◽  
Carl H. Schiesser ◽  
Stefanie-Ann Alexander
Keyword(s):  
Nitric Oxide ◽  
Pseudomonas Aeruginosa ◽  
Free Radicals ◽  
Free Radical ◽  
Fluorescent Probes ◽  
Direct Detection ◽  
Radical Formation ◽  
Turn On ◽  
Blue Cell ◽  
Free Radical Formation

Novel blue cell-permeable ‘turn-on’ fluorescent probes have been developed to visualize and quantify nitric oxide and free radical formation and reaction within aPseudomonas aeruginosabiofilm.

Spectrochemistry of Polycarbohydrate Free Radicals Generated by Argon Plasmolysis: Effect of Tertiary Structure on Free Radical Formation

1994 ◽  
Vol 98 (44) ◽  
pp. 11301-11307 ◽  
Author(s):  
Masayuki Kuzuya ◽  
Kazue Morisaki ◽  
Junji Niwa ◽  
Yukinori Yamauchi ◽  
Kaijun Xu
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Tertiary Structure ◽  
Radical Formation ◽  
Free Radical Formation

scholarly journals Wound-induced Free-radical Formation in Corn Seedlings

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 897C-897
Author(s):  
Mitiku Girma ◽  
Alex I. Smirnov
Keyword(s):  
Free Radical ◽  
Epr Spectroscopy ◽  
Radical Formation ◽  
Single Line ◽  
Epr Spectrum ◽  
Paramagnetic Resonance ◽  
Root Injury ◽  
Free Radical Formation ◽  
G Value ◽  
Radical Signal

Recent studies performed at the Univ. of Sheffield (Sheffield, England) have established a correlation between the onset of senescence and the loss of viability in plants with a development of stable free-radicals that can be observed by Electron Paramagnetic Resonance (EPR) spectroscopy. We explored the possibility of free-radical formation following root injury of corn seedlings (Zea mays L.). Free radical signals were detected by EPR spectroscopy at 9.5 GHz. In all cases, we observed a single-line free-radical signal (g value ≈2.004) superimposed with six-line EPR spectrum from Mn2 + ions naturally present in the plant tissues. We determined a consistent increase in the intensity of single-line EPR signal after inducing root injury. This signal presumably is attributed to a quinone-derived radical and, as speculated, is associated with stressed respiratory transport chains. Based on our results, we suggest that free-radical reactions can be induced by root injury. Furthermore, an appearance of free-radical signal in the root may serve as an indication of a stress, natural and induced. If the precursors of observed free-radical signal can be determined, this will provide better insight on free-radical processes in plants followed by an injury. This work used the resources of the Illinois EPR Research Center (NIH P4 1 -RR0 1811).

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