scholarly journals Free Radical Scavenging Activity of Five Benzoic Acid Derivatives: A Theoretical M06-2X Study

2022 ◽  
Author(s):  
Bienfait Kabuyaya Isamura ◽  
Issofa Patouossa ◽  
Isaac Kaba Elaka ◽  
Aristote Matondo ◽  
Pius Tshimankinda Mpiana
Keyword(s):  
Electron Transfer ◽  
Free Radical ◽  
Benzoic Acid ◽  
Gas Phase ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Basis Set ◽  
Antioxidant Power ◽  
Benzoic Acid Derivatives

The meta hybrid M06-2X functional combined with the 6-311++G(d,p) basis set are used to investigate the antioxidant activity of five benzoic acid derivatives naturally occurring in several plant food: gallic acid, para-hydroxybenzoic acid, protocatechuic acid, syringic acid and vanillic acid. To assess the antioxidant properties of these compounds, three mechanisms of free radicals scavenging are considered, namely the hydrogen atom transfer (HAT), stepwise electron transfer proton transfer (SET-PT) and sequential proton loss electron transfer (SPLET) models. The effect of polar environments on the antioxidant power of these compounds is mimicked in water and methanol using the IEF-PCM solvation method. Our findings suggest that HAT is the preferred mechanistic pathway in gas phase, while SPLET is favoured in polar mediums. Protocatechuic and gallic acids are the most active in gas and polar solutions respectively, whereas PHBA is the least active in all the environments considered. The O-H group in para position of the carboxylic group (O3-H for GA and O2-H for the rest) is confirmed to be the most reactive site in gas phase, while in solution it is either of the O1-H site (for PHBA, PCA, SA and VA) or O4-H groups (for GA). The “HOMO-rule” of free radical scavenging ability does not seem to account properly for the antioxidant properties of this set of chemicals.

scholarly journals FREE RADICAL SCAVENGING ACTIVITY OF MARINE SPONGES COLLECTED FROM KOVALAM, CHENNAI

2017 ◽  
Vol 10 (6) ◽  
pp. 321 ◽  
Author(s):  
Yuvarani Thambidurai ◽  
Sudarsanam D ◽  
Habeeb Skm ◽  
Ashok Kumar T
Keyword(s):  
Free Radical ◽  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Marine Sponges ◽  
Free Radical Scavenging Activity ◽  
Scavenging Activity ◽  
Frap Assay ◽  
Antioxidant Power

Objective: The main focus of this study is to screen the marine sponges for potent free radical scavenging activity. Methods: Various methods such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assay are employed to ascertain the antioxidant properties of marine sponges namely Dysidea herbacea and Sigmadocia pumila. Results: On analyzing, the result of ABTS assay D. herbacea and S. pumila exhibited almost equal antioxidant properties. While calculating the inhibitory concentration 50% value for DPPH assay, the Sample 1 and 2 has an IC of 655.49 and 826.739 μl, respectively, and in FRAP assay, the Sample 1 and 2 has an IC of 67.587 and 74.57 μg, respectively. Conclusion: Overall from this assay, D. herbacea revealed slightly better antioxidant activity when compared to S. pumila, also which in future may serve as a better source to fight against various diseases

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 In vitro inhibitory potentials of ethanolic extract of Moringa oleifera flower against enzymes activities linked to diabetes

2021 ◽  
Vol 10 (4) ◽  
pp. 408-414
Author(s):  
Oluwaseun Ruth Olasehinde ◽  
Olakunle Bamikole Afolabi ◽  
Benjamin Olusola Omiyale ◽  
Oyindamola Adeniyi Olaoye
Keyword(s):  
Free Radical ◽  
Moringa Oleifera ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Ethanolic Extract ◽  
Antidiabetic Activity ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Antioxidant Power

Introduction: Diabetes mellitus (DM) has been recognized as the seventh leading cause of global mortality; however, researchers seek alternative means to manage the menace. The current study sought to investigate antioxidant potentials, α-amylase, and α-glucosidase inhibitory activities of ethanolic extract of Moringa oleifera flower in vitro. Methods: Antioxidant properties of the extract were appraised by assessing its inhibition against 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl (OH•), and hydrogen peroxide (H2O2) free radicals, as well as ferric reducing antioxidant power (FRAP), the antidiabetic activity was evaluated by α-amylase and α-glucosidase inhibition.Results: In this study, ethanolic extract of M. oleifera flower demonstrated a significant (P < 0.05) inhibition against DPPH free radical (43.57–83.56%) in a concentration-dependent manner, while FRAP (101.76 ± 1.63 mg/100 g), OH• scavenging ability (71.62 ± 0.95 mg/100 g), and H2O2 free radical scavenging capacity (15.33 ± 1.20 mg/100 g) were also observed. In the same manner, ethanolic extract of M. oleifera flower revealed a significant (P < 0.05) inhibition against α-amylase (IC50= 37.63 mg/mL) and α-glucosidase activities (IC50= 38.30 mg/mL) in the presence of their respective substrates in a concentration-dependent manner in comparison with acarbose. Conclusion: Ethanoic extract of M. oleifera flower could be useful as an alternative phytotherapy in the management of DM, having shown a strong antioxidative capacity and substantial inhibition against the activities of key enzymes involved in carbohydrate hydrolysis in vitro.

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

Theoretical insight into the substituent effects on the antioxidant properties of 8-hydroxyquinoline derivatives in gas phase and in polar solvents

2018 ◽  
Vol 96 (5) ◽  
pp. 453-458
Author(s):  
Anes El-Hadj Saïd ◽  
Sidi Mohamed Mekelleche ◽  
Taki-Eddine Ahmed Ardjani
Keyword(s):  
Electron Transfer ◽  
Gas Phase ◽  
Antioxidant Properties ◽  
Substituent Effects ◽  
Hydrogen Atom Transfer ◽  
Polar Solvents ◽  
Antioxidant Power ◽  
Theoretical Insight ◽  
Insight Into

The objective of this work is to perform a theoretical analysis of the antioxidant properties of a series of 8-hydroxyquinolines (8-HQs) to rationalize the available experimental results and to design new potent 8-HQ derivatives. The study was carried out in gas phase and in methanol at the DFT/B3LYP/ 6-311++G(d,p) computational level. The formation of stable ArO• radicals is discussed on the basis of different mechanisms, namely, hydrogen atom transfer (HAT), single electron transfer followed by proton transfer (SET-PT), and single proton loss electron transfer (SPLET). The obtained results show that the HAT mechanism is, thermodynamically, more favoured in gas phase, whereas the SPLET pathway is more favoured in polar solvents. The calculated thermochemical descriptors allow classification of the antioxidant power of the studied compounds.

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 Profiling Metabolites and Biological Activities of Sugarcane (Saccharum officinarum Linn.) Juice and its Product Molasses via a Multiplex Metabolomics Approach

Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 934 ◽  
Author(s):  
Sara Ali ◽  
Rania El Gedaily ◽  
Andrei Mocan ◽  
Mohamed Farag ◽  
Hesham El-Seedi
Keyword(s):  
Mass Spectrometry ◽  
Free Radical ◽  
Nmr Spectroscopy ◽  
Radical Scavenging ◽  
Saccharum Officinarum ◽  
Free Radical Scavenging ◽  
Sugarcane Juice ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Total Phenolic ◽  
Antioxidant Power

Sugarcane (Saccharum officinarum L.) is an important perennial grass in the Poaceae family cultivated worldwide due to its economical and medicinal value. In this study, a combined approach using mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy was employed for the large-scale metabolite profiling of sugarcane juice and its by-product molasses. The polyphenols were analysed via UPLC-UV-ESI-MS, whereas the primary metabolites such as sugars and organic and amino acids were profiled using NMR spectroscopy and gas chromatography/mass spectrometry (GC/MS). UPLC/MS was more effective than NMR spectroscopy or GC/MS for determining differences among the metabolite compositions of the products. Under the optimized conditions, UPLC/MS led to the identification of 42 metabolites, including nine flavonoids, nine fatty acids, and two sterols. C/O Flavone glycosides were the main subclass detected, with tricin-7-O-deoxyhexosyl glucuronide being detected in sugarcane and molasses for the first time. Based on GC/MS analysis, disaccharides were the predominant species in the sugarcane juice and molasses, with sucrose accounting for 66% and 59%, respectively, by mass of all identified metabolites. The phenolic profiles of sugarcane and molasses were further investigated in relation to their in vitro antioxidant activities using free radical scavenging assays such as 2,2-Diphenyl-1-picrylhydrazyl free radical-scavenging ability (DPPH), Trolox equivalent antioxidant capacity (TEAC) and ferric reducing antioxidant power (FRAP). In view of its higher total phenolic content (TPC) (196 ± 2.1 mg GAE/100 g extract) compared to that of sugarcane juice (93 ± 2.9 mg GAE/100 g extract), molasses exhibited a substantially higher antioxidant effect. Interestingly, both extracts were also found to inhibit α-glucosidase and α-amylase enzymes, suggesting a possible antihyperglycaemic effect. These findings suggest molasses may be a new source of natural antioxidants for functional foods.

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