Antioxidant properties of ethenyl indole: DPPH assay and TDDFT studies

2020 ◽  
Vol 44 (21) ◽  
pp. 8960-8970 ◽  
Author(s):  
Jagdeep Kumar ◽  
Naresh Kumar ◽  
Nitin Sati ◽  
Prasanta Kumar Hota

Ethenyl indole exhibits antioxidant activity in a substituent dependent manner. Ethenyls bearing strong electron withdrawing substituents show weak or no antioxidant activities, whereas ethenyls with electron donating substituents exhibit antioxidant properties comparable to vitamin E.

2009 ◽  
Vol 15 (5) ◽  
pp. 435-444 ◽  
Author(s):  
Zuofa Zhang ◽  
Jie Jin ◽  
Liangen Shi

The antioxidant properties and total phenolic contents of four fractions of ethanolic extract from Ramulus mori were examined. Various experimental models including superoxide radical, hydroxyl radical, 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH) scavenging activity, metal chelating activity, and reducing power were used for characterization of their antioxidant activity. The four fractions showed various degrees of efficacy in each assay in a dose-dependent manner. The third fraction with the highest amount of total phenolics was the most potent antioxidant in all assays used. In addition, the most powerful compound (oxyresveratrol) was isolated and identified followed by on-line HPLC method and characterized by different spectral analysis. Oxyresveratrol exhibited impressive antioxidant activities in scavenging the superoxide radical, hydroxide radical, and DPPH. On the basis of the results obtained, Ramulus mori may serve as a potential source of natural antioxidant due to its significant antioxidant activity and oxyresveratrol may be the most powerful antioxidant in ethanolic extracts of Ramulus mori.


2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Mampolelo M. Photolo ◽  
Vuyo Mavumengwana ◽  
Lungile Sitole ◽  
Matsobane G. Tlou

This study reports on the isolation and identification of Methylobacterium radiotolerans MAMP 4754 from the seeds of the medicinal plant, Combretum erythrophyllum, for the purposes of investigating antimicrobial and antioxidant activities from this endophyte. The strain identity was confirmed by 16S rRNA-based phylogeny and Scanning Electron Microscopy (SEM). Ethyl acetate and chloroform (1 : 1 v/v) extracts from the endophyte were tested for antimicrobial and antioxidant activity on a total of 7 bacterial species (3 Gram-positive and 4 Gram-negative) using the standard Minimum Inhibitory Concentration (MIC) protocol and Quantitative Radical Scavenging activity using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay, respectively. The MICs were recorded at 250 μg/mL for B. subtilis ATCC 19659, B. cereus ATCC 1076, E. coli ATCC1053, and 62.5 μg/mL for K. oxytoca ATCC 13182 and M. smegmatis ATCC 21293, while an IC50 of 5.65 μg/mL was recorded with the DPPH assay. Qualitative phytochemical analysis was positive for alkaloids, flavonoids, and steroids. Gas chromatography/mass spectrometry (GC/MS) analysis revealed the presence of 9-octadecene, 2,4-dinitrophenyl acetate, and 2(5H)-furanone, which have been previously reported for the targeted activities. M. radiotolerans MAMP 4754 tested positive for antimicrobial and antioxidant activity and this is linked to the production of plant-derived secondary metabolites by this strain.


2021 ◽  
Vol 11 (1) ◽  
pp. 19
Author(s):  
Virdah Dwi Dewaantari ◽  
Setyabudi Setyabudi ◽  
Kun Ismiyatin

Background: Free radicals are molecules without any electron pairs, unstable, and highly reactive. Antioxidants are needed to reduce free radicals. Antioxidants provide various benefits in dentistry as a preventive agent for caries, healing, bone formation, mouthwash, preventive and therapeutic cancer, and reduction of periodontal disease progressions. Additionally, research on antioxidants is still undergone due to the existence of free radical residues on bleached teeth. Epigallocatechin-3-gallate (EGCG), ascorbic acid (AA), and sodium ascorbate (SA) are ingridients that have antioxidant properties. Antioxidants can be in two forms solution and gel. Solutions have a higher substance releasing power than gel. Gel is extremely adhesive, so it does not flow easily. Meanwhile, solutions are rather unstable because it flows easily. Antioxidant activities were evaluated with 2,2-diphenyl-1-picrylhydrazyl (DPPH) Assay method. Purpose: Analyzing through literature reviews the potential antioxidants of EGCG, AA, and SA in solution and gel forms by DPPH Assay. Reviews: There were eight journal articles used in this review. The first article described antioxidant solutions in which EGCG was higher than sodium ascorbate. The second article showed that antioxidant gel EGCG was lower than sodium ascorbate. The third journal explained that ascorbic acid was higher than sodium ascorbate both in solution and gel forms. The other articles provided some information about the antioxidant activity percentages of EGCG, SA, and AA in the forms of gel and solutions by DPPH assay. Conclusion: EGCG has a higher antioxidant activity than SA, but it is lower when compared to AA in both solution and gel forms by DPPH assay.


2019 ◽  
Vol 13 (4) ◽  
pp. 277-283 ◽  
Author(s):  
Mohammad Hossein Morowvat ◽  
Sara Goharian ◽  
Younes Ghasemi

Background and Objectives: In this study, three naturally isolated species of microalgae were investigated for their antioxidant activity using DPPH assay and polyphenol contents through Folin-Ciocalteu analysis. Methods: Three different solvents including hexane, ethyl acetate and water, which present different polarities were utilized to extract the bioactive components from three different microalgal strains. Results: The investigated species exhibited considerable amounts of antioxidants (25.88 ± 0.48 µmol Trolox g-1 in Scenedesmus obliquus) and polyphenol compounds (27.14 ± 0.40 mg GAE g-1 in Chlorella vulgaris). The observed correlation coefficient (R2=0.8265) between the two studied parameters confirmed the great contribution of the phenolic compounds in the observed antioxidant activities. Conclusion: The phylogenetics and other bioinformatic tools were confirmed as a useful method for identification of the most prominent species. The obtained data and patents warrant the potentials of naturally isolated microalgal strains for obtaining different antioxidant and polyphenolic bioactive compounds.


Food Research ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 475-484
Author(s):  
M.C.R. Ilano ◽  
K.J.D. Sartagoda ◽  
L.E.L. Flandez ◽  
M.C.M. Compendio ◽  
D.B. Morales ◽  
...  

Lipote (Syzygium polycephaloides (C. B. Rob.) Merr.) is a Philippine endemic tree whose berries have a potential for functional food development. This study aimed to investigate the effect of the maturity stage (unripe, half-ripe or fully ripe) and processing (blanching at 90±5°C for 2 mins and steaming at 105±5°C for 5 mins) on the antioxidant content (total phenolic content (TPC), total flavonoid content (TFC), and total anthocyanin content (TAC)) and antioxidant activity by DPPH, ABTS, and FRAP assays, of lipote flesh and skin (referred herein as flesh) and seeds. Results showed that maturity and processing significantly affect the antioxidant contents and activities of fresh lipote flesh and seeds. Blanched lipote flesh generally had higher TPC, TFC, and antioxidant activities than their unprocessed and steamed counterparts. Blanched unripe flesh had the highest TPC (33.57±0.27 mg gallic acid equivalents [GAE]/g) and antioxidant activity measured by ABTS, FRAP, and DPPH assay (92.31±1.28 mg Trolox equivalents [TE]/g, 123.83±0.86 mg TE/g, and 74.02±0.33 mg TE/g, respectively) while blanched fully ripe flesh had the highest TFC (27.98±0.08 mg quercetin equivalents [QE]/g) and TAC (18.11±0.11 mg cyanidin-3-glucoside equivalents [C3GE]/g). Lipote seeds, especially unripe ones, have appreciable antioxidant contents and antioxidant activity, even greater than that of lipote flesh. Unprocessed unripe seeds had the greatest TPC, TFC and antioxidant activity by DPPH assay (123.56±0.94 mg GAE/g, 111.90±0.14 mg QE/g and 465.89±1.86 mg TE/g, respectively). It is recommended that blanching be used as a processing step to increase the antioxidant content of lipote flesh while lipote seeds should be investigated further for nutraceutical applications due to their high antioxidant properties.


2011 ◽  
pp. 151-157 ◽  
Author(s):  
Marijana B. Saka ◽  
Julianna F. Gyura ◽  
Aleksandra Mišan ◽  
Zita I. Šereš ◽  
Biljana S. Pajin ◽  
...  

The antioxidant activity of cookies prepared by the addition of sugarbeet dietary fibers was investigated in order to estimate their influence on functional characteristics and shelf-life of cookies. Treated fiber (TF) was obtained from sugarbeet by extraction with sulfurous acid (75 °C at pH = 5.7during 60 min) and treatment with hydrogen peroxide (20 g/LH2O2 at pH = 11 during 24 h). The fiber obtained was dried (80 °C), ground and sieved. TF was investigated in comparison with commercially available Fibrex®. The cookies were prepared by the addition of 0, 7, 9 and 11% of sugarbeet dietary fiber as a substitute for wheat flour in the formulation of cookies. The antioxidant properties of cookies were tested every 7 days using a DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity test during 6 weeks of storage at room temperature (23 ± 1 ºC). The obtained results indicated that substitution of wheat flour with Fibrex® in the formulation of cookies upgraded the antioxidant activity, i.e. the functional characteristics of Fibrex®-enriched cookies and could prolong their shelf-life. In contrast, TF did not increase the antioxidant activity of TF-enriched cookies. The better antioxidant activities of Fibrex®-enriched cookies could be attributed to the presence of ferulic acid.


Author(s):  
Hadi Shariati ◽  
Mohammad Hassanpour ◽  
Gholamreza Sharifzadeh ◽  
Asghar Zarban ◽  
Saeed Samarghandian ◽  
...  

Objective: The present study has been carried out to evaluate the diuretic and antioxidant properties of pine herb in an animal model. Materials and Methods: 45 adult male rats were randomly divided into nine groups including: groups I (the negative control), groups II (positive control, furosemide 10 mg/kg), groups III to VIII (treatment groups received 100, 200, 400 mg/kg of the aqueous extracts of bark and fruit) and group IX received the combination of aqueous extract of bark (100 mg/kg) and the fruit (100 mg/kg). The urine output, glomerular filtration rate (GFR), electrolytes, urea, and creatinine levels were evaluated . Furthermore, the phenolic content and antioxidant activity of both extracts were also assessed using 2, 2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and Folin–Ciocalteu methods. Results: The aqueous extracts of the pine bark and fruit increased the urinary output in a dose-dependent manner. The combination of the two extracts compared to the other extracts alone significantly increased the serum potassium level. This study also showed each extract increase creatinine clearance in a dose-dependent manner (p<0.01 and p<0.05). The increase of GFR in the combination group was not significant. The current data showed a significant increase in the total phenolic content in pine bark extract in compared with the fruit extract. Conclusion: The pine bark and fruit can be useful in the prevention and treatment of kidney stones due to the high antioxidant activity.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
E. S. Prasedya ◽  
A. Frediansyah ◽  
N. W. R. Martyasari ◽  
B. K. Ilhami ◽  
A. S. Abidin ◽  
...  

AbstractSample particle size is an important parameter in the solid–liquid extraction system of natural products for obtaining their bioactive compounds. This study evaluates the effect of sample particle size on the phytochemical composition and antioxidant activity of brown macroalgae Sargassum cristaefolium. The crude ethanol extract was extracted from dried powders of S.cristeafolium with various particle sizes (> 4000 µm, > 250 µm, > 125 µm, > 45 µm, and < 45 µm). The ethanolic extracts of S.cristaefolium were analysed for Total Phenolic Content (TPC), Total Flavonoid Content (TFC), phenolic compound concentration and antioxidant activities. The extract yield and phytochemical composition were more abundant in smaller particle sizes. Furthermore, the TPC (14.19 ± 2.08 mg GAE/g extract to 43.27 ± 2.56 mg GAE/g extract) and TFC (9.6 ± 1.8 mg QE/g extract to 70.27 ± 3.59 mg QE/g extract) values also significantly increased as particle sizes decreased. In addition, phenolic compounds epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC), and Epigallocatechin gallate (EGCG) concentration were frequently increased in samples of smaller particle sizes based on two-way ANOVA and Tukey’s multiple comparison analysis. These results correlate with the significantly stronger antioxidant activity in samples with smaller particle sizes. The smallest particle size (< 45 µm) demonstrated the strongest antioxidant activity based on DPPH, ABTS, hydroxyl assay and FRAP. In addition, ramp function graph evaluates the desired particle size for maximum phytochemical composition and antioxidant activity is 44 µm. In conclusion, current results show the importance of particle size reduction of macroalgae samples to increase the effectivity of its biological activity.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4518
Author(s):  
Raquel Sousa ◽  
Artur Figueirinha ◽  
Maria Teresa Batista ◽  
Maria Eugénia Pina

Cymbopogon citratus DC (Stapf.) is a perennial grass and it is distributed around the world. It is used as a condiment for food and beverage flavouring in the form of infusions and decoctions of its dried leaves. Our previous studies have shown antioxidant, anti-inflammatory and gastroprotective activities for the infusion and its phenolic fractions. The aim of the present work was to develop oral dosage forms from a Cymbopogon citratus extract to be used as a functional food with antioxidant properties. Initially, an essential oil-free infusion was prepared, lyophilized and characterized by HPLC-PDA. Total phenols were quantified with the Folin–Ciocalteu method and the antioxidant activity was assessed by DPPH assay. Gelatine capsules containing the extract with different excipients, selected after DSC and IR trials, were prepared. A formulation exhibiting better antioxidant behaviour in a gastric environment was attained. These results suggest that the proposed formulation for this extract could be a valuable antioxidant product and, consequently, make an important contribution to “preventing” and minimizing diseases related to oxidative stress conditions.


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1127 ◽  
Author(s):  
Beatriz Chamorro ◽  
David García-Vieira ◽  
Daniel Diez-Iriepa ◽  
Estíbaliz Garagarza ◽  
Mourad Chioua ◽  
...  

Herein, we report the neuroprotective and antioxidant activity of 1,1′-biphenyl nitrones (BPNs) 1–5 as α-phenyl-N-tert-butylnitrone analogues prepared from commercially available [1,1′-biphenyl]-4-carbaldehyde and [1,1′-biphenyl]-4,4′-dicarbaldehyde. The neuroprotection of BPNs1-5 has been measured against oligomycin A/rotenone and in an oxygen–glucose deprivation in vitro ischemia model in human neuroblastoma SH-SY5Y cells. Our results indicate that BPNs 1–5 have better neuroprotective and antioxidant properties than α-phenyl-N-tert-butylnitrone (PBN), and they are quite similar to N-acetyl-L-cysteine (NAC), which is a well-known antioxidant agent. Among the nitrones studied, homo-bis-nitrone BPHBN5, bearing two N-tert-Bu radicals at the nitrone motif, has the best neuroprotective capacity (EC50 = 13.16 ± 1.65 and 25.5 ± 3.93 μM, against the reduction in metabolic activity induced by respiratory chain blockers and oxygen–glucose deprivation in an in vitro ischemia model, respectively) as well as anti-necrotic, anti-apoptotic, and antioxidant activities (EC50 = 11.2 ± 3.94 μM), which were measured by its capacity to reduce superoxide production in human neuroblastoma SH-SY5Y cell cultures, followed by mononitrone BPMN3, with one N-Bn radical, and BPMN2, with only one N-tert-Bu substituent. The antioxidant activity of BPNs1-5 has also been analyzed for their capacity to scavenge hydroxyl free radicals (82% at 100 μM), lipoxygenase inhibition, and the inhibition of lipid peroxidation (68% at 100 μM). Results showed that although the number of nitrone groups improves the neuroprotection profile of these BPNs, the final effect is also dependent on the substitutent that is being incorporated. Thus, BPNs bearing N-tert-Bu and N-Bn groups show better neuroprotective and antioxidant properties than those substituted with Me. All these results led us to propose homo-bis-nitrone BPHBN5 as the most balanced and interesting nitrone based on its neuroprotective capacity in different neuronal models of oxidative stress and in vitro ischemia as well as its antioxidant activity.


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