Colorimetric evaluation of the hydroxyl radical scavenging ability of antioxidants using carbon-confined CoOx as a highly active peroxidase mimic

2019 ◽  
Vol 186 (6) ◽  
Author(s):  
Hongwei Song ◽  
Xin Li ◽  
Yanfang He ◽  
Yinxian Peng ◽  
Jianming Pan ◽  
...  
Keyword(s):  
Hydroxyl Radical ◽  
Radical Scavenging ◽  
Peroxidase Mimic ◽  
Highly Active ◽  
Radical Scavenging Ability ◽  
Colorimetric Evaluation

scholarly journals Synthesis and Antioxidant Properties of Novel 2-(2,4-Dioxothiazolidin-5-ylidene)-Acetamides Containing 1,3,4-Thia/Oxadiazole Moieties

2021 ◽  
Vol 12 (5) ◽  
pp. 6710-6722
Keyword(s):  
Ascorbic Acid ◽  
Acetyl Chloride ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Scavenging Effect ◽  
Highly Active ◽  
Ethanol Medium ◽  
Ic50 Value ◽  
Radical Scavenging Ability

A series of novel 1,3,4-thia(oxa)diazole substituted 2-(2,4-dioxothiazolidine-5-ylidene)-acetamides 3a-c, 4 and 5a-k have been synthesized following the acylation reaction of 2-amino-5-aryl-1,3,4-oxadiazoles, 5-amino-1,3,4-thiadiazole-2-thiol and it’s S-alkylated derivatives with 2-(2,4-dioxothiazolidine-5-ylidene)acetyl chloride in dioxane medium. The functionalization of compounds 3b, 3c, 5d and 5e was carried out on their N3 position under N-alkylation conditions with N-aryl-2-chloroacetamides in DMF/ethanol medium yielded the corresponding 2,4-dioxothiazolidine-3,5-diacetic acid diamides 6a-e and 7a-b. The structures of target compounds were confirmed by using 1H NMR spectroscopy and elemental analysis. The antioxidant activity evaluation in vitro of the synthesized compounds was performed by the method of scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. As a result, the highly active compound 4, namely 2-(2,4-dioxothiazolidin-5-ylidene)-N-(5-mercapto-[1,3,4]thiadiazol-2-yl)acetamide was found to be the most efficient candidate among all compounds with a radical scavenging ability of 88.9%, which was comparable that for ascorbic acid (92.7%). The experimentally calculated IC50 value of 43.1 µM for compound 4 was lower than for ascorbic acid (50.5 µM).

scholarly journals Investigation of the Key Pharmacological Activities of Ficus racemosa and Analysis of Its Major Bioactive Polyphenols by HPLC-DAD

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Salma Akter Sumi ◽  
Md. Afjalus Siraj ◽  
Amir Hossain ◽  
Md. Sagir Mia ◽  
Seagufta Afrin ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Cytotoxic Activity ◽  
Superoxide Radical ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Tannin Content ◽  
Phenolic Constituents ◽  
Ficus Racemosa ◽  
Radical Scavenging Ability

Objective. Oxidative stress leads to numerous physiological disorders including infectious diseases, inflammation, and cancer. The present study was carried out to investigate antioxidant, antibacterial, and cytotoxic activity of methanol crude extract of leaves and fruits of the Ficus racemosa (LCME and FCME, resp.) and to analyse its major bioactive polyphenols by HPLC-DAD. Methods. Antioxidant capacity of the extracts was evaluated by DPPH free radical scavenging, reducing power, total phenolic, total flavonoid, total tannin content assay, superoxide radical, hydroxyl radical, and hydrogen peroxide scavenging assay. Identification and quantification of bioactive polyphenols were done by HPLC-DAD method. Antibacterial activity was tested by “disc diffusion” method. Brine shrimp lethality assay was carried out to check the cytotoxic potential. Result. Both LCME and FCME showed DPPH scavenging ability and concentration dependent reducing power activity. They had phenolic content, flavonoid content, and tannin content. Both the extracts showed superoxide radical scavenging ability, hydroxyl radical scavenging ability, and hydrogen peroxide scavenging ability. HPLC analysis of LCME and FCME indicated the presence of significant amount of gallic acid along with other phenolic constituents. Conclusion. Significant amount of gallic acid along with other phenolic constituents might have played an important role in the observed antioxidant, antibacterial, and cytotoxic activity.

Hydroxyl radical scavenging ability of bacterioruberin

1997 ◽  
Vol 50 (3) ◽  
pp. 267-269 ◽  
Author(s):  
Takeshi Saito ◽  
Yuko Miyabe ◽  
Hiroshi Ide ◽  
Osamu Yamamoto
Keyword(s):  
Hydroxyl Radical ◽  
Radical Scavenging ◽  
Radical Scavenging Ability

scholarly journals EVALUATION OF FREE RADICAL SCAVENGING ABILITY AND ANTIRADICAL ACTIVITIES OF XIMENIA CAFFRA FRUIT EXTRACTS AT DIFFERENT RIPENING STAGES

2019 ◽  
Vol 11 (1) ◽  
pp. 55
Author(s):  
Pensia E. Mapunda ◽  
Cosmas Mligo ◽  
Herbert V. M. Lyaruu
Keyword(s):  
Nitric Oxide ◽  
Free Radicals ◽  
Free Radical ◽  
Hydroxyl Radical ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Human Beings ◽  
Ripening Stage ◽  
Fruit Extracts ◽  
Radical Scavenging Ability

Methods: Using standard procedures, Ximenia caffra fruit extracts were determined for ferrous ions chelating ability, nitric oxide and hydroxyl radical scavenging ability. Antiradical activities were assessed using 1,1-diphenyl-2-picrylhydrazyl (DPPH) in which the fruit extracts were evaluated for the number of antiradical units (AU515), the number of antiradical units per 1 mg of extracts (EAU515) and the total number of antiradical units per 1g of raw fruits (TAU515).Results: The fruit extracts exhibited significant higher ferrous ion chelating and free radical scavenging capacity compared to synthetic antioxidants (standard). Fruit extracts in early ripening stage (ERS) exhibited stronger ion chelation, nitric oxide and hydroxyl radical scavenging ability with low effective fruit extract concentration required to reduce free radicals by 50% (EC50) that were 14, 25 and 30µg/ml respectively than the late ripening stage (LRS) extracts. The fruit extracts also showed high AU515, EAU515 and TAU515. The values of AU515 ranged from 0.93 to 0.95, while EAU515 from 78.30 to 79.34 and TAU515 ranged from 19762.46 to 23821.23 of the extracts in LRS and ERS respectively.Conclusion: Based on these observations Ximenia caffra is potentially beneficial to human health due to its strong ability to scavenge free radicals. Its utilization can potentially reduce the risk of degenerative diseases to human beings.

scholarly journals Characterization and Biological Activity of a Novel Exopolysaccharide Produced By Pediococcus Pentosaceus SSC-12 From Silage

2021 ◽  
Author(s):  
Yang Fan ◽  
Xinqin Li ◽  
Rong Tian ◽  
Ruxue Tang ◽  
Jianguo Zhang
Keyword(s):  
Hydroxyl Radical ◽  
High Performance ◽  
Biological Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Antibacterial Properties ◽  
Exchange Chromatography ◽  
Pediococcus Pentosaceus ◽  
Pharmaceutical Industries ◽  
Radical Scavenging Ability

Abstract Background: The exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) are widely used in various fields because of their safety and various biological activities. In this study, we extracted and characterized the composition as well as antioxidant and antibacterial activities of EPS from Pediococcus pentosaceus SSC-12 isolated from the silage.Results: The LAB strain SSC-12 was screened and identified as Pediococcus pentosaceus, based upon 16S rDNA gene sequencing and Neighbor Joining (NJ) phylogenetic analysis. The analysis of the EPS production kinetics results of SSC-12 showed that the EPS production reached the maximum at 20 h of culture. High-performance anion exchange chromatography (HPAEC) analysis showed that the EPS produced by SSC-12 was a heteropolysaccharide comprising glucose (42.6 %), mannose (28.9 %), galactose (16.2 %), arabinose (9.4 %) and rhamnose (2.9 %). The EPS had good antioxidant activity, especially hydroxyl radical scavenging activity. When the concentration of the EPS produced by SSC-12 (SSC-12 EPS) was 10 mg/mL, its 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging ability, hydroxyl radical scavenging ability, superoxide scavenging ability, and reduction ability were 77.4 %, 97.5 %, 77.5 % and 1.3, respectively. At 10 mg/mL，SSC-12 EPS completely killed Staphylococcus aureus GDMCC 1.1220 and substantially inhibited the growth of Salmonella enterica subsp. enterica GDMCC 1.345; however, it had a weak inhibitory effect on Listeria monocytogenes GDMCC 1.347. Conclusions: Due to its strong antioxidant and antibacterial properties, EPS produced by LAB strain SSC-12 have potential application as a bioactive product in the feed, food, and pharmaceutical industries.

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