scholarly journals Establishment of the Antioxidant/Antiradical Activity of the Inhibitors Using the DPPH–Radical

2008 ◽  
Vol 3 (1) ◽  
pp. 118-126
Author(s):  
Maria Gonta ◽  
Gheorghe Duca ◽  
Diana Porubin

This research paper presents the results of the investigation of antioxidant activities of various inhibitors, which are constituents of winery products: quercitin, rezveratrol, dihydroxyfumaric acid. Also, the antioxidant activity of tartaric and dihydroxyfumaric (DFH4) acids derivatives has been determined: sodium dihydroxyfumarate, dimethylic ester of DFH4 and dimethylic ester of tartaric acid. The enotannin extracts obtained from grape seeds have been evaluated: the non-oxidized enotannin extract Eneox and the oxidized one -Enoxil.

Author(s):  
Reine Raïssa Rolande Aworet Samseny ◽  
Line-Edwige Mengome ◽  
Sophie Aboughe Angone

Aims: Free radicals are involved in many diseases. Antioxidants help control them. The overproduction of free radicals or reduction of natural antioxidants promotes the destruction of cells in our body, for example in neurodegenerative diseases. The aim of our study is to evaluate the correlation between the level of polyphenol and antioxidant activity of Dichrostachys cinerea barks he work was carried out at the phytochemistry department of the Institute of Pharmacopoeia and Traditional Medicine (Gabon). Methodology: Different extracts of Dichrostachys cinerea barks were obtained with polarity solvent (dichloromethane, ethyl acetate, butanol, methanol and water).  The antioxidant activity is evaluating using respectively FRAP method (Ferric Reducing Antioxidant Power), antiradical activity by the method of inhibition of DPPH radical (2.2-diphenyl-1-picrylhydrazyl), cations ABTS radical (2.2'-azinobis-[3-acid-6-sulfonic ethylenzothiazoline]). Results: Ethyl acetate and dichloromethane extract have the higher value for polyphenolic compounds, respectively 52,27±0,66 mg EAG / g and 49,72±0,55 mg EAG / g. Aqueous extract have the lower value 20,67±1,05 mg EAG / g. The different fractions of Dichrostachys cinerea have antioxidant effect, and this effect is in correlation with its constituents: polyphenols, tannins and flavonoids. Results were compared to standard antioxidants such as ascorbic acid and quercetin. Conclusion: This study confirms higher is the level of polyphenols greater is the antioxidant power.


2009 ◽  
Vol 27 (Special Issue 1) ◽  
pp. S245-S247 ◽  
Author(s):  
M. Krpan ◽  
K. Marković ◽  
G. Šarić ◽  
B. Skoko ◽  
M. Hruškar ◽  
...  

The antioxidant activities and total phenolic content of 30 samples of acacia honey from Croatian territory were analysed. Phenolics were determined by the modified Folin-Ciocalteu method, antiradical activity by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and potential antioxidant activity using the ferric reducing antioxidant power (FRAP) method. In all samples, physicochemical parameters (water content, electrical conductivity, total reducing sugars, sucrose content, acidity, hydroxymethylfurfural content, prolin content, optical rotation, diastase activity and invertase activity) were measured according to Croatian legislation and International regulatory standards. Honey can be considered as a dietary supplement as it contains some important components including α-tocopherol, ascorbic acid, flavonoids and phenolics. The composition and properties of honey are dependent on floral origins, climatic conditions of the produced area, processing and storage methods. The results of physicochemical analyses showed that all the values of investigated parameters are in agreement with the current legislation. Phenolic content ranged from 31.72 mg/kg to 80.11 mg/kg, antiradical activity expressed as IC50 ranged from 61.28% to 253.47% and antioxidant activity expressed as FRAP value from 6.95 to 142.43. A positive correlation was observed between total phenolic content and antioxidant activity, indicating that phenolic compounds are mainly responsible for the antioxidant power of acacia honey.


2018 ◽  
Vol 10 (1) ◽  
pp. 44 ◽  
Author(s):  
Riza Shabrina ◽  
Berna Elya ◽  
Arikadia Noviani

Objective: This study aimed to fractionate the antioxidant activity of the ethyl acetate leaf extract and to characterize the most active fractionsaccording to compound groups.Methods: The ethyl acetate extract was fractionated with column chromatography using a gradient elution system. Fractions were first screenedqualitatively for antioxidant activity before active fractions were quantified with respect to in vitro antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and the ferric-reducing antioxidant power (FRAP) assay. The compound groups were identifiedfollowing separation by thin-layer chromatography.Results: Fraction 11 exhibited the greatest DPPH radical-scavenging activity, with an IC50 value of 6.58 μg/mL, while the fraction with the greatestantioxidant activity according to the FRAP assay was fraction 10, with a ferric ion equivalent antioxidant activity value of 1015.34 μmol/g.Conclusion: Compound group identification revealed that Fractions 10 and 11 contained flavonoids, with two common to both fractions, whilefraction 10 also contained one specific flavonoid.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Mayron Alves Vasconcelos ◽  
Francisco Vassiliepe Sousa Arruda ◽  
Daniel Barroso de Alencar ◽  
Silvana Saker-Sampaio ◽  
Maria Rose Jane Ribeiro Albuquerque ◽  
...  

This study evaluated the effect of derriobtusone A, a flavonoid isolated fromLonchocarpus obtusus, on two important pathogenic bacteria,Staphylococcus aureusandEscherichia coli, as well as its antioxidant activity and toxicity. Planktonic growth assays were performed, and the inhibition of biofilm formation was evaluated. In addition, antioxidant activity was assessed by DPPH radical scavenging assay, ferrous ion chelating assay, ferric-reducing antioxidant power assay, andβ-carotene bleaching assay. Toxicity was evaluated by the brine shrimp lethality test. Results showed that derriobtusone A completely inhibited the planktonic growth ofS. aureusat 250 and 500 μg/mL; however, it did not have the same activity onE. coli. Derriobtusone A reduced the biomass and colony-forming unit (cfu) ofS. aureusbiofilm at concentrations of 250 and 500 μg/mL. In various concentrations, it reduced the biofilm biomass ofE. coli, and, in all concentrations, it weakly reduced the cfu. Derriobtusone A showed highly efficient antioxidant ability in scavenging DPPH radical and inhibitingβ-carotene oxidation. The compound showed no lethality toArtemiasp. nauplii. In conclusion, derriobtusone A may be an effective molecule againstS. aureusand its biofilm, as well as a potential antioxidant compound with no toxicity.


2015 ◽  
Vol 804 ◽  
pp. 195-198
Author(s):  
Supha Kanthang ◽  
Kanokporn Sompornpailin

Flavonoids are compounds which act as antioxidants in both plant and human. These substances are found in reproductive tissues. Tobaccos expressing ORF of PRODUCTION OF ANTHOCYANIN PIGMENT 1 (PAP1) involved in flavonoid biosynthesis were used for investigating the flavonoid profiles and antioxidant activity of petals and compared to wild type (WT) tobacco. Approximately two months, the tobacco grown in a culturing room had produced flowers for harvesting. The petal tissues were extracted with the solvent of acidic methanol and water. These extracts were measured the specific wavelength of flavonoid derivatives by using a spectrophotometer. The petal extract of H7 line showed the highest content of all detected flavonoid subgroups. However the petal extract of transgenic line H5 and H7 had significantly higher levels of anthocyanin (pelargonidin) than those of the other transgenic and WT tobaccos. An antioxidant activity of the petal extract was evaluated by 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) assay. An effective concentration of the extract which scavenged DPPH radical by 50% (EC50) was presented. EC50 of the H5 and H7 transgenic extracts was approximately two folds less than that of WT extract Therefore anthocyanin may highly affect on antioxidant activities.


2019 ◽  
Vol 22 (1) ◽  
pp. 73 ◽  
Author(s):  
Jelita Rahma Hidayati ◽  
Ervia Yudiati ◽  
Delianis Pringgenies ◽  
Zaenal Arifin ◽  
Diah Tri OktaviyantI

Exposure of sunlight lead tropical Sargassum sp. to maintain their growth and moreover to bring up their secondary metabollite for life struggling. Sargassum sp. has bioactive compounds that has a potential antioxidant acitivity such as phenolic compounds as well as chlorophyll and carotenoids. This research was conducted to determine antioxidant activities, phenolic compound and pigmens of Sargassum sp. with different solvent that have different polarities. Sample was macerate with n-heksana, ethyl acetate, methanol and aquadest. All the parameters were done spectrophotometrically. IC50 was used to determine the antioxidant activity by antiradical scavenging activity using DPPH (515 nm). Total phenolic compound were tested by Folin-Ciocalteu solution  and used gallic acid as standard (725 nm). The chlorophylls a content were measured at wavelength 662 nm and 645 nm and carotenoids were measured at wavelength 470 nm. The results showed best IC50 is achieved by aquadest extract (72.95 ±0.22 ppm). The highest Total phenolic compound is achieved by ethyl acetat extract (120.29 ±0,404 mg GAE/g sample). The highest chlorophyll a content is achieved by ethyl acetat extract (18.23 ± 0,049 mg/g sample) and the highest carotenoid content is achieved by ethyl acetat extract extract (60.65 ±0,008  µmol/g sample). It can be concluded that aquadest extract can be categorized as the strong antioxidant and antiradical activity, ethyl acetat as a medium antioxidant activity. The simple and save methods of aquadest extract promising that Sargassum  sp. frorn Indonesia is a good candidate compoud for nutraceutical and cosmeceutical approach.  


2018 ◽  
Vol 7 (2) ◽  
Author(s):  
Hamadia Khurshid ◽  
Syed Mubashar Sabir ◽  
Shahid Iqbal Awan ◽  
Syed Rizwan Abbas ◽  
Muhammad Irshad

Rose petals have been applied as food additives in teas, cakes and flavor extracts. The aim of this research study was to explore and reveal the antioxidant potential of aqueous extracts of rose petals belonging to nine genotypes of rose (wild as well as hybrid). The in vitro antioxidant activities of roses were studied by lipid peroxidation assay, DPPH radical scavenging assay, iron chelation assay, phosphomolybdenum reduction assay and total phenolic and flavonoid contents. The aqueous extract showed inhibition against lipid peroxidation (TBARS), induced by prooxidants (10 µM FeSO4) in mice liver homogenate. The free radical scavenging activities of the extracts were determined by scavenging of the DPPH radical. Extracts also showed metal chelating activities and high antioxidant activity in the phosphomolybdenum assay. The high content of phenolics and flavonoids detected in aqueous extracts may be responsible for the antioxidant activity. Amongst the different rose genotypes, screened, Rosa moschata (musk rose) was found to carry slightly higher antioxidant potential, owing to its higher phytochemical content.


2018 ◽  
Vol 55 (5A) ◽  
pp. 134
Author(s):  
Ngo Minh Ngoc

Soybean (Glycine max) and soy milk residue (okara) are protein-rich materials. Soybean possesses the highest protein content among different types of beans (protein content of soybean varies from 40–42 %). Soy milk residue, a by-product of the soy milk manufacturing industry, contains approximately 27 % protein (by dry weight). A number of recent studies have investigated the improvement of functional properties of protein contained in soybean and okara by fermentation or by the use of proteolytic enzymes. The aim of this study was to evaluate the antioxidant activities of soybean and okara hydrolysates obtained by the fermentation with Aspergillus oryzae or by using proteolytic enzymes (neutrase and flavourzyme). DPPH radical scavenging assay was used to determine the antioxidant activities of hydrolysates. The concentration of peptides required to scavenge DPPH radical by 50 % (IC50 value) was used to evaluate the antioxidant activity of peptides produced obtained from hydrolysates. The results showed that when fermented with A. oryzae, the okara hydrolysate had higher antioxidant activity than the soybean hydrolysate, with IC50 values of 0.447 mg/ml and 3.95 mg/ml, respectively. The hydrolyzed okara obtained from hydrolysis using Neutrase had higher antioxidant activity than the one obtained from hydrolysis using Flavourzyme, with IC50 values of0.200 mg/ml and 0.407 mg/ml, respectively. Different peptide fractions obtained from the hydrolysates using cut-off membrane (10 kDa, 3 kDa and 1 kDa) possessed different antioxidant activities. The < 1 kDa peptide fraction exhibited the highest antioxidant activity with an IC50 value of 0.158 mg/ml.


Author(s):  
Djankou Tchoffo Madeleine ◽  
Nyemb Jean Noël ◽  
Atchade A. de Theodore ◽  
Hamidou Abdoulaye ◽  
Talla Emmanuel ◽  
...  

Aims: The present study was conducted to determine the antioxidant activity and chemical components of Ficus abutilifolia. Miq. (Moraceae). Place and Duration of the Study: The study were performed at Department of chemistry, University of Ngaoundere, Cameroon, between July 2017 and September 2018. Methodology: Phytochemical study was carried out on all extracts of stem barks. Besides, the total phenols contents (TPC) using the Folin-Ciocalteu and the antioxidant activities using DPPH and FRAP methods were also evaluated. The isolation of compounds from the EtOAc extract was done using column and thin layer chromatographic techniques on silica gel. The structures of isolated constituents were elucidated using mass spectrometry, 1D and 2D-NMR techniques. Results: Phytochemical screening revealed that all the compounds tested were found to be present in the acetone extract; the hexane extract was the poorest in compounds. Acetone extract, DCM/MeOH (1:1) and MeOH extracts were found to be rich in phenols with TPC respectively (239. 849 ± 0.969), (232.676 ± 0.404) and (109.654 ± 0.724) mg EAG/100g EX. Except the n-hexane extract, all the others exhibit antioxidant activities, acetone extract being the most effective with an inhibitory concentration 50 (IC50) of (0.038 ± 0.002) mg/mL for the DPPH antiradical scavenging activity and (0,021 ± 0,002) mg/mL for FRAP. A new fatty acid named Pentacosyl henicosanoate (2) along with six known compounds Octatriacontane (1), β–sitosterol (3), a mixture of Lupeol acetate (4a), α-amyrin acetate (4b), β-amyrin acetate (4c) and Daucosterol (5) were isolated from the column chromatography of the ethyl acetate extract. Daucosterol (5) exhibited antiradical activity with an IC50 of (13.005 ± 0.005) mg/mL. Only Daucosterol (5) has exhibited antiradical activity with an IC50 of (13.005 ± 0.005) mg/mL among the isolated compounds. Conclusion: This study provides scientific evidence and support for the traditional uses of F. abutilifolia stem barks in the treatment of diseases associated with oxidative stress.


Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3664
Author(s):  
Lingyun Zhong ◽  
Lianxin Peng ◽  
Jia Fu ◽  
Liang Zou ◽  
Gang Zhao ◽  
...  

The chemical components, as well as the antibacterial and antioxidant activities of the essential oil (EO) and crude extracts prepared from Rhodiola crenulata were investigated. The essential oil was separated by hydrodistillation, and gas chromatography-mass spectrometry (GC-MS) was used to identify its constituents. A total of twenty-seven compounds was identified from the EO, and its major components were 1-octanol (42.217%), geraniol (19.914%), and 6-methyl-5-hepten-2-ol (13.151%). Solvent extraction and fractionation were applied for preparing the ethanol extract (crude extract, CE), petroleum ether extract (PE), ethyl acetate extract (EE), n-butanol extract (BE), and water extract (WE). The CE, EE and BE were abundant in phenols and flavonoids, and EE had the highest total phenol and total flavonoid contents. Gallic acid, ethyl gallate, rosavin and herbacetin were identified in the EE. The antibacterial activity results showed that the EO exhibited moderate inhibitory activity to the typical clinic bacteria, and EE exhibited the strongest antibacterial activity among the five extracts. For the compounds, ethyl gallate showed the strongest inhibitory activity to the test bacteria, and its minimum inhibitory concentration (MIC) value and minimum bactericidal concentration (MBC) value for all the tested bacteria was 0.24 mg/mL and 0.48 mg/mL, respectively. The results of antioxidant activity showed that both CE and EE exhibited strong antioxidant activities in the DPPH radical scavenging and Fe2+ reducing power tests, however, EO showed relatively weaker antioxidant ability. Ethyl gallate and rosavin exhibited excellent activity in the DPPH radical scavenging assay, and their IC50 value was 5.3 µg/mL and 5.9 µg/mL, respectively. Rosavin showed better reduction power activity than the other three compounds. These results could provide more evidence for the traditional use of R. crenulata, and would be helpful for improving its application further.


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