scholarly journals Assessment of Antioxidant Activity of Pure Graphene Oxide (GO) and ZnO-Decorated Reduced Graphene Oxide (rGO) Using DPPH Radical and H2O2 Scavenging Assays

2019 ◽  
Vol 5 (4) ◽  
pp. 75 ◽  
Author(s):  
Nacera Baali ◽  
Assia Khecha ◽  
Aicha Bensouici ◽  
Giorgio Speranza ◽  
Noudjoud Hamdouni
Keyword(s):  
Antioxidant Activity ◽  
Zinc Oxide ◽  
Graphene Oxide ◽  
Antioxidant Activities ◽  
In Vitro Assays ◽  
Dependent Manner ◽  
Mass Ratio ◽  
Dpph Radical ◽  
Scavenging Efficiency

In this work, zinc oxide-decorated graphene oxide (ZnO–rGO) was successfully synthesized with a fast reflux chemical procedure at 100 °C. An equal mass ratio of graphene oxide (GO) and zinc acetate was used as starting materials dissolved, respectively, in ultrapure distilled water and dimethylformamide (DMF). Particularly, pure GO was synthesized using Hummers modified protocol by varying the mass ratio of (graphite:potassium permanganate) as follows: 1:2, 1:3, and 1:4, which allow us to obtain six types of pure and decorated samples, named, respectively, GO1:2, GO1:3, GO1:4, ZnO–rGO1:2, ZnO–rGO1:3, and ZnO–rGO1:4 using reflux at 100 °C. X-ray diffraction, FTIR, and Raman spectroscopy spectra confirm the formation of wurzite ZnO in all ZnO-decorated samples with better reduction of GO in ZnO–rGO1:4, confirming that a higher degree of graphene oxidation allows better reduction during the decoration process with ZnO metal oxide. Antioxidant activity of pure and zinc oxide-decorated graphene oxide samples were compared using two different in vitro assays (DPPH radical and H2O2 scavenging activities). Considerable in vitro antioxidant activities in a concentration-dependent manner were recorded. Interestingly, pristine GO showed more elevated scavenging efficiency in DPPH tests while ZnO-decorated GO was relatively more efficient in H2O2 antioxidant assays.

scholarly journals Identification of phenolic secondary metabolites from Schotia brachypetala Sond. (Fabaceae) and demonstration of their antioxidant activities in Caenorhabditis elegans

2016 ◽  
Author(s):  
Mansour Sobeh ◽  
Esraa A ElHawary ◽  
Herbenya Peixoto ◽  
Rola M Labib ◽  
Heba Handoussa ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Caenorhabditis Elegans ◽  
Nuclear Translocation ◽  
Antioxidant Activities ◽  
In Vitro Assays ◽  
Flavonoid Glycosides ◽  
Alcoholic Extract ◽  
C Elegans

Background: Schotia brachypetala Sond. (Fabaceae) is an endemic tree of Southern Africa whose phytochemistry and pharmacology were slightly studied.The present work aimed at profiling the major phenolics compounds present in the hydro-alcoholic extract from S. brachypetala leaves (SBE) using LC/HRESI/MS/MS and NMR and prove their antioxidant capabilities using novel methods. Methods: In vitro assays; DPPH, TEAC persulfate decolorizing kinetic and FRAP assays, and in vivo assays: Caenorhabditis elegans strains maintenance, Intracellular ROS in C. elegans, Survival assay, GFP expression and Subcellular DAF-16 localization were employed to evaluate the antioxidant activity. Results: More than forty polyphenols ,including flavonoid glycosides, galloylated flavonoid glycosides, isoflavones, dihydrochalcones, procyanidins, anthocyanins, hydroxybenzoic acid derivatives, hydrolysable tannins, and traces of methylated and acetylated flavonoid derivatives were identified. Three compounds were isolated and identified from the genus Schotia for the first time, namely gallic acid, myricetin-3-O-α-L-1C4-rhamnoside and quercetin-3-O-L-1C4-rhamnoside.The tested extract was able to protect the worms against juglone induced oxidative stress and attenuate the reactive oxygen species (ROS) accumulation. SBE was also able to attenuate the levels of heat shock protein (HSP) expression. Discussion: A pronounced antioxidant activity in vivo, which can be attributed to its ability to promote the nuclear translocation of DAF-16/FOXO, the main transcription factor regulating the expression of stress response genes. The remarkable antioxidant activity in vitro and in vivo correlates to SBE rich phenolic profile.

scholarly journals Synthesis, Spectroscopic Study and Radical Scavenging Activity of Kaempferol Derivatives: Enhanced Water Solubility and Antioxidant Activity

2019 ◽  
Vol 20 (4) ◽  
pp. 975 ◽  
Author(s):  
Sui-Ping Deng ◽  
Yi-Li Yang ◽  
Xing-Xing Cheng ◽  
Wen-Rong Li ◽  
Ji-Ye Cai
Keyword(s):  
Antioxidant Activity ◽  
Water Solubility ◽  
High Resolution Mass Spectrometry ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Dependent Manner ◽  
Thermal Methods ◽  
Vis Spectroscopy

Kaempferol (Kae) is a natural flavonoid with potent antioxidant activity, but its therapeutic use is limited by its low aqueous solubility. Here, a series of Kae derivatives were synthesized to improve Kae dissolution property in water and antioxidant activity. These compounds included sulfonated Kae (Kae-SO3), gallium (Ga) complexes with Kae (Kae-Ga) and Kae-SO3 (Kae-SO3-Ga). The compound structures were characterized by high-resolution mass spectrometry (HRMS), nuclear magnetic resonance (NMR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and thermal methods (TG/DSC). The results showed that a sulfonic group (-SO3) was successfully tethered on the C3’ of Kae to form Kae-SO3. And in the metal complexation, 4-CO and 3-OH of the ligand participated in the coordination with Ga(III). The metal-to-ligand ratio 1:2 was suggested for both complexes. Interestingly, Kae-SO3-Ga was obviously superior to other compounds in terms of overcoming the poor water-solubility of free Kae, and the solubility of Kae-SO3-Ga was about 300-fold higher than that of Kae-Ga. Furthermore, the evaluation of antioxidant activities in vitro was carried out for Kae derivatives by using α,α-diphenyl-β-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS) free radical scavenging. The results showed that Kae-SO3-Ga was also optimal for scavenging free radicals in a dose-dependent manner. These data demonstrate that sulfonate kaempferol-gallium complex has a promising future as a potential antioxidant and as a potential therapeutic agent for further biomedical studies.

scholarly journals Phytochemical Investigation and In Vitro Antioxidant Activities of Tetracarpidium conophorum (African Walnut) Seeds

2018 ◽  
Vol 6 (2) ◽  
pp. 56-61
Author(s):  
Kelly Oriakhi ◽  
Kissinger Orumwensodia ◽  
Patrick Uadia
Keyword(s):  
Nitric Oxide ◽  
Antioxidant Activity ◽  
Methanol Extract ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Phytochemical Screening ◽  
Dpph Radical ◽  
Dpph Radical Scavenging ◽  
Crude Methanol Extract

Background: Tetracarpidium conophorum (African walnut) is an African plant with ethnobotanical uses. Objectives: The purpose of this study was to evaluate the phytochemical screening and in vitro antioxidant activities of methanol extract and fractions (F) [n-hexane (HEX-F), dichloromethane (DCM-F) and, ethyl acetate (EA-F)] of T. conophorum seeds. Methods: Phytochemical screening and in vitro antioxidant activity study were carried out using DPPH, ABTs radical scavenging assays, nitric oxide inhibitory and reducing potential assays. Results: Methanol extract and its fractions contain phenols, flavonoids, saponins, tannins, terpenoids, and alkaloids. The concentrations of total phenols and flavonoids content were significantly higher in EA-F and crude methanol extract compared to other fractions. Crude methanol and EA-F contain higher concentrations of tannin while hexane fraction had the lowest tannin content but relatively higher proanthocyanidin content compared to other fractions. The antioxidant activity study showed that both methanol crude extract and fractions of T. conophorum seeds have significant activities for DPPH radical scavenging, reducing power, ferric reducing antioxidant potential, nitric oxide inhibitory activities, ABTS and hydroxyl radical scavenging for. DPPH radical scavenging activities of EA-F showed the lowest IC50 of 33.11 µg/mL, followed by Hex-F, DCM-F and crude methanol extract with IC50 of 33.43, 42.09 and 45.44 µg/mL, respectively, when compared to ascorbic acid with IC50 of 17.08 µg/mL. Conclusion: The study showed that T. conophorum seed is a rich source of secondary metabolites, which may be responsible for its antioxidant activities.

scholarly journals In vitro antioxidant activity of stem bark of Trichilia catigua Adr. Juss

2012 ◽  
Vol 62 (3) ◽  
pp. 371-382 ◽  
Author(s):  
Jean Paul Kamdem ◽  
Sílvio Terra Stefanello ◽  
Aline Augusti Boligon ◽  
Caroline Wagner ◽  
Ige Joseph Kade ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Ethanolic Extract ◽  
Stem Bark ◽  
Total Phenolic ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
High Concentrations ◽  
Dpph Scavenging

Antioxidant activity of the ethanolic extract and fractions from the stem bark of T. catigua was investigated. IC50 (for DPPH scavenging) by T. catigua varied from 9.17 ± 0.63 to 76.42 ± 5.87 mg mL-1 and total phenolic content varied from 345.63 ± 41.08 to 601.27 ± 42.59 mg GAE g-1 of dry extract. Fe2+-induced lipid peroxidation was significantly reduced by the ethanolic extract and fractions. Mitochondrial Ca2+-induced dichlorofluorescein oxidation was significantly reduced by the ethanolic extract in a concentration-dependent manner. Ethanolic extract reduced mitochondrial Dym only at high concentrations (40-100 mg mL-1), which indicates that its toxicity does not overlap with its antioxidant effects. Results suggest involvement of antioxidant activities of T. catigua in its pharmacological properties.

scholarly journals Acetone Extract fromRhodomyrtus tomentosa: A Potent Natural Antioxidant

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Goodla Lavanya ◽  
Supayang Piyawan Voravuthikunchai ◽  
Nongporn Hutadilok Towatana
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Antioxidant Property ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Antioxidant Power ◽  
Lipid Peroxidation Inhibition

Rhodomyrtus tomentosa(Myrtaceae) has been employed in traditional Thai medicine to treat colic diarrhoea, dysentery, abscesses, haemorrhage, and gynaecopathy. In addition, it has been used to formulate skin-whitening, anti-aging and skin beautifying agents. Ethnomedical activities of this plant may be due its antioxidant property. Hence, the aim of this study was to evaluate bothin vitroandin vivoantioxidant activities ofR. tomentosaleaf extract.In vitroantioxidant activity of the extract was assessed by lipid peroxidation inhibition capacity, ferric reducing antioxidant power, and metal chelating activity.R. tomentosaextract demonstrated its free radical scavenging effects in concentration dependent manner.In vivoantioxidant activity of the extract was conducted in SwissAlbinomice. Levels of thio-barbituric acid reactive substances (TBARS), glutathione (GSH), and the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in blood, liver, and kidney were analyzed using microtitre plate photometer. Administration of CCl4caused significant increase in TBARS and decrease in GSH, SOD, CAT and GPx levels. In contrast,R. tomentosaextract (0.8 g/kg) effectively prevented these alterations and maintained the antioxidant status. The results suggest thatR. tomentosaextract can serve as a potent antioxidant.

scholarly journals Identification of phenolic secondary metabolites from Schotia brachypetala Sond. (Fabaceae) and demonstration of their antioxidant activities in Caenorhabditis elegans

2016 ◽  
Author(s):  
Mansour Sobeh ◽  
Esraa A ElHawary ◽  
Herbenya Peixoto ◽  
Rola M Labib ◽  
Heba Handoussa ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Caenorhabditis Elegans ◽  
Nuclear Translocation ◽  
Antioxidant Activities ◽  
In Vitro Assays ◽  
Flavonoid Glycosides ◽  
Alcoholic Extract ◽  
C Elegans

Background: Schotia brachypetala Sond. (Fabaceae) is an endemic tree of Southern Africa whose phytochemistry and pharmacology were slightly studied.The present work aimed at profiling the major phenolics compounds present in the hydro-alcoholic extract from S. brachypetala leaves (SBE) using LC/HRESI/MS/MS and NMR and prove their antioxidant capabilities using novel methods. Methods: In vitro assays; DPPH, TEAC persulfate decolorizing kinetic and FRAP assays, and in vivo assays: Caenorhabditis elegans strains maintenance, Intracellular ROS in C. elegans, Survival assay, GFP expression and Subcellular DAF-16 localization were employed to evaluate the antioxidant activity. Results: More than forty polyphenols ,including flavonoid glycosides, galloylated flavonoid glycosides, isoflavones, dihydrochalcones, procyanidins, anthocyanins, hydroxybenzoic acid derivatives, hydrolysable tannins, and traces of methylated and acetylated flavonoid derivatives were identified. Three compounds were isolated and identified from the genus Schotia for the first time, namely gallic acid, myricetin-3-O-α-L-1C4-rhamnoside and quercetin-3-O-L-1C4-rhamnoside.The tested extract was able to protect the worms against juglone induced oxidative stress and attenuate the reactive oxygen species (ROS) accumulation. SBE was also able to attenuate the levels of heat shock protein (HSP) expression. Discussion: A pronounced antioxidant activity in vivo, which can be attributed to its ability to promote the nuclear translocation of DAF-16/FOXO, the main transcription factor regulating the expression of stress response genes. The remarkable antioxidant activity in vitro and in vivo correlates to SBE rich phenolic profile.

scholarly journals ANTIOXIDANT ACTIVITY TEST OF FRACTIONS FROM STAR FRUIT LEAVES (AVERRHOA CARAMBOLA L.) FROM THREE REGIONS IN WEST JAVA

2020 ◽  
pp. 97-100
Author(s):  
ANNISA DHANIRA ◽  
BERNA ELYA ◽  
KATRIN BASAH
Keyword(s):  
Antioxidant Activity ◽  
Ethyl Acetate ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Dpph Radical ◽  
Leaf Extracts ◽  
Frap Assay ◽  
Star Fruit

Objectives: Previous in vitro research showed that ethyl acetate fractions of star fruit leaves exhibit strong antioxidant activities toward 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (IC50 = 90 μg/ml). This study’s aim was to evaluate antioxidant activity of fractions from leaf extracts from star fruitsourced from three different regions in Indonesia (Depok, Sukabumi, and Subang) and, for the most active fraction (that with the highest antioxidantactivity), determine whether there was any correlation with phenolic and flavonoid content.Methods: Liquid–liquid partitioning, fractions were evaluated for in vitro antioxidant activity using DPPH radical scavenging and ferric reducingability of plasma (FRAP) assay.Results: The ethyl acetate fraction from the Subang region exhibited the strongest radical scavenging activity with both the DPPH assay (IC50 = 96 μg/ml)and the FRAP assay (FeEAC value = 1405 μmol/g).Conclusion: Ethyl acetate fractions from star fruit leaves could be used as natural antioxidants. No correlation was found between antioxidant activityand phenolic or flavonoid content.

Four Flavonoid Glycosides from the Pulps of Elaeagnus angustifolia and their Antioxidant Activities

2013 ◽  
Vol 756-759 ◽  
pp. 16-20 ◽  
Author(s):  
Ya Wang ◽  
Tao Guo ◽  
Jia Yin Li ◽  
Shang Zhen Zhou ◽  
Ping Zhao ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Reducing Power ◽  
Flavonoid Glycosides ◽  
Dependent Manner ◽  
Elaeagnus Angustifolia ◽  
Superoxide Anions ◽  
Dpph Radical ◽  
First Time ◽  
Dose Dependent

Four flavonoid glycosides were isolated from the pulps of Elaeagnus angustifolia and identified as Quercetin 3,4'-O-β-D-diglucoside (1), Isorhamnetin-3-O-β-D-galactopy-ranoside (2), Quercetin 3-O-β-D-Galactopyranoside-4'-O-β-D-glucopyranoside (3) and Isorhamnetin 3-O-β-D-Galacto-pyranoside-4'-O-β-D-glucopyranoside (4). Among which, the compounds 1, 3 and 4 were isolated for the first time from this plant. The antioxidant activities of the four compounds were evaluated by measuring their reducing power and ability to scavenge the ABTS radical, DPPH radical and to inhibit superoxide anions. The results indicated that theses compounds exhibited antioxidant activities with a dose-dependent manner in all tested models, and had some structureactivity relationships. The order of potential antioxidant capacity was as follows:1>3>2>4. Considering related reports, the flavonoid might be responsible for antioxidant activity of pulps of E. angustifolia.

scholarly journals In Vitro and In Vivo Antioxidative Activity against Radiation-Induced Damage and the Systematic Chemical Components of Different Extracts of Lagotis brevituba Maxim

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Dan Zhang ◽  
Lihong Tan ◽  
Ling Yao ◽  
Wei Tao ◽  
Ruixue Gong ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Whole Body ◽  
Chemical Components ◽  
Control Group ◽  
Dependent Manner ◽  
Antioxidant Assays ◽  
Radiation Induced

Lagotis brevituba Maxim is a perennial species distributed in the highlands of China, which has been used for more than 2000 years as a traditional Tibetan medicinal plant. However, no attention has been paid to the antioxidant activities of Lagotis brevituba Maxim in vitro or in vivo. Thus, this study aimed to evaluate the in vitro and in vivo antioxidant activity of Lagotis brevituba Maxim against radiation-induced damage as well as the systematic chemical components. To explore the relationship between the antioxidant activity and extraction solvent, Lagotis brevituba Maxim was extracted with three different solvents: methanol, water, and acetone. In antioxidant assays in vitro, the water extract had the strongest reducing power, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity compared with the methanol and acetone extracts. However, the methanol extract was more potent in the β-carotene/linoleic acid cooxidation assay. In antioxidant assays in vivo, mice that were exposed to 6.0 Gy60Co γ-ray whole-body radiation on day 15 after administration of Lagotis brevituba Maxim decreased their level of malondialdehyde (MDA) in a dose-dependent manner compared with the control group, indicating that Lagotis brevituba Maxim had favorable antioxidant activities in vivo. In addition, a total of 44 compounds were tentatively identified by liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS), including 19 flavonoids, 14 phenols, 8 phenylethanoid glycosides, 2 iridoid glycosides, and 1 carbohydrate. We obtained 25 compounds from plants in the genus Lagotis for the first time. These results suggested that Lagotis brevituba Maxim had potent antioxidant activity and could be explored as a novel natural antioxidant.

SYNTHESIS AND ANTIOXIDANT ACTIVITY OF SOME NEW SULFONAMIDE DERIVATIVES

2021 ◽  
Author(s):  
Jovana M. Muškinja ◽  
◽  
Jelena S. Katanić Stanković ◽  
Zoran R. Ratković
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Biological Activities ◽  
Point Of View ◽  
Important Class ◽  
Dpph Radical ◽  
Sulfa Drugs ◽  
Nmr Methods ◽  
In Vitro Antioxidant Activity

Sulfonamide derivatives are a very important class of compounds with pronounced biological activities and, for this reason, they have very useful pharmaceutical applications. They are the basis of several groups of drugs and are known as sulfa-drugs. From this point of view, the present study focuses on the synthesis of some novel structural hybrids incorporating two very important groups, sulfonamide, and pyrazoline. The new sulfonamide-based pyrazolines were synthesized in very good yields. The structures of the sulfonamide compounds were confirmed by IR and NMR methods. Synthesized compounds were tested for their antioxidant activities using two different methods, DPPH radical and ABTS radical cation scavenging assays. The results showed relatively good in vitro antioxidant activity.

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