Effects of pH Alteration on the Free Radical Scavenging Ability and Other Antioxidant Properties of Reduced Glutathione

2015 ◽  
Vol 8 (1) ◽  
pp. 1-10
Author(s):  
T. Ogunmoyole ◽  
I. Kade
Keyword(s):  
Free Radical ◽  
Reduced Glutathione ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Effects Of Ph ◽  
Radical Scavenging Ability

Flavones and Their Analogues as Bioactive Compounds – An Overview

2019 ◽  
Vol 16 (4) ◽  
pp. 377-391 ◽  
Author(s):  
B.S. Jayashree ◽  
H. Venkatachalam ◽  
Sanchari Basu Mallik
Keyword(s):  
Biological Activity ◽  
Free Radical ◽  
Bioactive Compounds ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Cost Effective ◽  
Free Radical Scavenging ◽  
Polyphenolic Compounds ◽  
Pharmacological Activities ◽  
Poor Solubility

Flavonoids constitute a large group of polyphenolic compounds that are known to have antioxidant properties, through their free radical scavenging abilities. They possess a chromone (γ- benzopyrone) moiety, responsible for eliciting many pharmacological activities. Even though, natural flavonoids are highly potent, owing to their poor solubility, they are less used. Therefore, attempts have been made to improve their stability, solubility, efficacy and kinetics by introducing various substituents on the flavone ring. For nearly the last two decades, flavones were synthesized in our laboratory by simple, convenient and cost-effective methods, with the knowledge of both synthetic and semi-synthetic chemistry. In this direction, it was considered worthwhile to present an overview on the synthesized flavonoids. This review creates a platform for highlighting various modifications done on the flavone system along with their biological activity.

scholarly journals Research antioxidant activity of chitooligosacchride by UV-VIS absorption spectrocopy

2020 ◽  
Vol 8 (1) ◽  
pp. 75-81
Author(s):  
Bui Van Hoai ◽  
Ngo Dai Nghiep ◽  
Dao An Quang ◽  
Nguyen Thi Nam Phuong
Keyword(s):  
Molecular Weight ◽  
Antioxidant Activity ◽  
Absorption Spectrum ◽  
Free Radical ◽  
Trichoderma Viride ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Free Radical Scavenging ◽  
Degree Of Deacetylation ◽  
Radical Scavenging Ability

Chitosan with 80% degree of deacetylation was hydrolyzed by cellulase of Trichoderma viride to prepare chitooligosaccharides (COSs) by the fractionation of the COSs with ultrafiltration membrane. The antioxidant activities of the COSs were clarified in this study by reducing power and free radical scavenging ability assay by UV-VIS absorption spectrum. The results show that the COS 1 (10,000-5,000 Da), COS 2 (5,000-3,000 Da), COS 3 (3,000-1,000 Da) and COS 4 (less than1,000 Da) segments have antioxidant properties.The antioxidant activitives of the COSs increased with the increment of concentration, and they also depended on molecular weight.

scholarly journals Antioxidant and antimicrobial activities against Enterobacter cloacae of extracts of Eclipta alba Hassk.

2016 ◽  
Vol 19 (4) ◽  
pp. 76-83
Author(s):  
Trang Thi Xuan Dai ◽  
Anh Thi Tu Vo
Keyword(s):  
Free Radical ◽  
Vitamin C ◽  
Ethyl Acetate ◽  
Ethyl Acetate Extract ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Enterobacter Cloacae ◽  
Free Radical Scavenging ◽  
Antioxidant Vitamin ◽  
Eclipta Alba

This study was subjected to investigate antimicrobial and antioxidant properties of Eclipta alba extracts (methanol, hexane, chloroform and ethyl acetate extracts). The antioxidant property of the extract was assessed by 2,2- diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. Kirby-Bauer method was used to determine the antibacterial activity against Enterobacter cloacae of the extracts. The extracts of Eclipta alba were tested against E. cloacae. The highest antibacterial potentiality was exhibited by the ethyl acetate extract of E. alba leaves, means of zones of bacterial growth inhibition are 26.3 mm at a concentration of 32 μg/mL. DPPH free radical scavenging effect of the extracts was compared with standard antioxidant vitamin C. The highest antioxidant activity was exhibited by the ethyl acetate extract of E. alba leaves. The result also showed that the DPPH scavenging activity of ethyl acetate extract from leaves of E. alba was high (EC50 = 419.38 μg/mL). However, this result was 18.99 times lower than that of vitamin C (EC50 = 22.08 μg/mL).

Free radical scavenging and antioxidant properties of conducting polymers examined using EPR and NMR spectroscopies

2005 ◽  
Vol 153 (1-3) ◽  
pp. 153-156 ◽  
Author(s):  
P.A. Kilmartin ◽  
M. Gizdavic-Nikolaidis ◽  
Z. Zujovic ◽  
J. Travas-Sejdic ◽  
G.A. Bowmaker ◽  
...  
Keyword(s):  
Free Radical ◽  
Conducting Polymers ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Free Radical Scavenging

scholarly journals The Free Radical Scavenging and Anti-Isolated Human LDL Oxidation Activities of Pluchea indica (L.) Less. Tea Compared to Green Tea (Camellia sinensis)

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Kittipot Sirichaiwetchakoon ◽  
Gordon Matthew Lowe ◽  
Griangsak Eumkeb
Keyword(s):  
Free Radical ◽  
Green Tea ◽  
Camellia Sinensis ◽  
Hypochlorous Acid ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Ldl Oxidation ◽  
Caffeoylquinic Acid ◽  
Dicaffeoylquinic Acid

Tea is one of the most popular beverages in the world. Camellia sinensis tea (CST) or green tea is widely regarded as a potent antioxidant. In Thailand, Pluchea indica (L.) Less. tea (PIT) has been commercially available as a health-promoting drink. This study focused on free radical scavenging activities of PIT, and its ability to protect isolated human low-density lipoproteins (LDL) from oxidation by chemical agents. A preliminary study to investigate the antioxidant nature of PIT was undertaken. These included common antioxidant assays involving 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS), hypochlorous acid (HOCl), and its potential to scavenge peroxynitrite. In separated experiments, isolated human LDL was challenged with either 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH), copper (Cu2+), or 3-Morpholinosydnonimine hydrochloride (SIN-1) to induce LDL oxidation. PIT exhibited antioxidant activity in all test systems and performed significantly better than CST in both DPPH (P<0.05; IC50PIT=245.85±15.83 and CST=315.41±24.18 μg/ml) and peroxynitrite scavenging assays. PIT at 75 μg/ml almost fully prevented the peroxynitrite over a 5 h period. Moreover, it displayed similar properties to CST during the antioxidation of isolated human LDL using AAPH, Cu2+, SIN-1, and hypochlorous acid scavenging assays. However, it revealed a significantly lower ABTS scavenging activity than CST (P<0.05; IC50PIT=30.47±2.20 and CST=21.59±0.67 μg/ml). The main constituents of the PIT were identified using LC-MS/MS. It contained 4-O-caffeoylquinic acid (4-CQ), 5-O-caffeoylquinic acid (5-CQ), 3,4-O-dicaffeoylquinic acid (3,4-CQ), 3,5-O-dicaffeoylquinic acid (3,5-CQ), and 4,5-O-dicaffeoylquinic acid (4,5-CQ). In conclusion, caffeoyl derivatives in PIT could play an important role in potent antioxidant properties. So, it may be further developed to be antioxidant beverages for preventing atherosclerosis and cardiovascular diseases associated with oxidative stress.

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