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 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).

scholarly journals Antioxidant Activity of Quercetin: A Mechanistic Review

2016 ◽  
Vol 4 (12) ◽  
pp. 1134 ◽  
Author(s):  
Senay Ozgen ◽  
Ozgur Kivilcim Kilinc ◽  
Zeliha Selamoğlu
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Cardiovascular Diseases ◽  
Chemical Structure ◽  
Radical Scavenging ◽  
Antioxidant Property ◽  
Free Radical Scavenging ◽  
Polyphenolic Compounds ◽  
Structure And Properties ◽  
Treatment Of Diabetes

Flavones and flavonoids are known to have potent antioxidant activity due to intracellular free radical scavenging capacities. Flavonoids are found ubiquitously in plants as a member of polyphenolic compounds which share diverse chemical structure and properties. Quercetin is among the most efficient antioxidants of the flavonoids. The antioxidant property of quercetin has been highlighted in this review. These compounds have pivotal role in treatment of diabetes, cancers and some cardiovascular diseases.

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.

scholarly journals Domestic Cooking Effects of Bambara Groundnuts and Common Beans in the Antioxidant Properties and Polyphenol Profiles

2017 ◽  
Vol 6 (2) ◽  
pp. 24 ◽  
Author(s):  
V. Nyau ◽  
S. Prakash ◽  
J. Rodrigues ◽  
J. Farrant
Keyword(s):  
Free Radical ◽  
Methanolic Extract ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Esi Ms ◽  
Positive Effects ◽  
Phytochemical Profiles

Processing of legumes before consumption has several effects on micronutrients, macronutrients and phytonutrients. This study was undertaken to investigate the effect of domestic processing on antioxidant activities and phenolic phytochemicals of the red bambara groundnuts and red beans. The study employed in vitro antioxidant assays (DPPH and FRAP) to screen for antioxidant properties, HPLC-PDA-ESI-MS and Folin Ciocalteu assay to screen for phenolic phytochemical profiles. Domestic cooking displayed positive effects on the antioxidant activity and phenolic phytochemical profiles of the two legumes. The free radical scavenging speed increased 10-fold in the methanolic extract from cooked red bambara groundnuts compared to uncooked. By contrast, the free radical scavenging speed increased 20-fold in the methanolic extract from cooked red beans compared to uncooked. HPLC-PDA-ESI-MS profiles of the cooked red bambara groundnuts and red beans revealed a number of emergent phenolic compounds, mainly flavonoids. These data indicate that cooking appear to enhance the nutraceutical profiles of the legumes investigated.

Allopurinol does not enhance antioxidant properties of extracellular fluid

1988 ◽  
Vol 255 (1) ◽  
pp. H202-H206 ◽  
Author(s):  
B. J. Zimmerman ◽  
D. A. Parks ◽  
M. B. Grisham ◽  
D. N. Granger
Keyword(s):  
Free Radical ◽  
Xanthine Oxidase ◽  
Hypochlorous Acid ◽  
Ischemia Reperfusion ◽  
Parenchymal Cell ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Extracellular Fluid ◽  
Free Radical Scavenging ◽  
Beneficial Effects

Allopurinol has been shown to provide significant protection against ischemia/reperfusion-induced microvascular and parenchymal cell injury. It has been hypothesized that the protection seen with allopurinol after ischemia/reperfusion (I/R) is caused by inhibition of xanthine oxidase. However, recent reports suggest that the beneficial effects of allopurinol in I/R may be caused by direct free radical scavenging. The objective of this study was to determine whether the regimen of allopurinol administration used in most I/R studies leads to a significant modification of the free radical scavenging properties of extracellular fluid (ECF), i.e., plasma and lymph. Plasma and intestinal lymph samples obtained from both control and allopurinol-treated cats were used to assess the following: 1) allopurinol and oxypurinol concentrations, 2) xanthine oxidase inhibition, 3) myoglobin-catalyzed linolenic acid peroxidation, 4) hypochlorous acid scavenging, and 5) protein and nonprotein sulfhydryl content. ECF from allopurinol-treated animals contained approximately 10 microM each of allopurinol and oxypurinol. Ten percent ECF resulted in 80% inhibition of xanthine oxidase activity. Comparable volumes of control ECF did not inhibit xanthine oxidase. Furthermore, allopurinol treatment did not enhance the antioxidant properties of ECF. The results of this study do not support the contention that the beneficial effects of allopurinol in I/R injury are caused by the scavenging of oxidants produced in ECF by activated granulocytes.

Preliminary phytochemical analysis and evaluation of antioxidant, cytotoxic and inhibition of lipopolysaccaride - induced NOS (iNOS) expression in BALB/c mice liver by Ziziphus oenoplia Mill. fruit

2017 ◽  
Vol 14 (2) ◽  
Author(s):  
Ramaraj Thirugnanasampandan ◽  
Gunasekar Ramya ◽  
Gunasekaran Bhuvaneswari ◽  
Srinivasan Aravindh ◽  
Suresh Vaishnavi ◽  
...  
Keyword(s):  
Free Radical ◽  
Bioactive Compounds ◽  
Tamil Nadu ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Phytochemical Analysis ◽  
Fruit Extract ◽  
Ms Analysis ◽  
Wide Range ◽  
Mice Liver

AbstractBackground:Mill. is an ethnomedicinal plant and its fruit has been traditionally used by Puliar tribes of Anamalai Hills, Tamil Nadu, India to treat various ailments. Phytochemical analysis, antioxidant, cytotoxic and inducible nitric oxide synthase (Methods:To explore bioactive compounds present in the ripened fruits, high-performance thin-layer chromatography (HPTLC) and gas chromatography/mass spectrometry (GC–MS) analysis were done. Free radical scavenging, hepatoprotective, inhibition ofResults:Total flavonoid content of ZOFwas estimated as 69 µg/mg catechin equivalent. HPTLC densitogram confirmed the presence of quercetin and GC–MS analysis showed a total of 16 compounds of 87.66 % with quinic acid as a major compound which accounted for 22.29 %. Free radical-scavenging activity of ethanolic fruit extract was ranged from 160.12 to 650.23 µg/mL. An amount of 1.5 µg lipopolysaccharide (LPS)- induced severe inflammation in BALB/c mice liver, followed by treatment with ethanolic fruit extract of 100 µg concentration, exhibited significant hepatoprotection and reverse transcriptase polymerase (RT-PCR) analysis showed downregulation ofConclusions:Findings of the present study prove that ZOF is a rich source of bioactive compounds with a wide range of pharmacological activities. Hence, consumption of this wild edible fruit will be a cost-effective and easily available natural nutritional source for health protection.

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