Antioxidant Activity of Selected Thyme (Thymus L.) Species and Study of the Equivalence of Different Measuring Methodologies

2015 ◽  
Vol 98 (4) ◽  
pp. 876-882 ◽  
Author(s):  
Marta Orłowska ◽  
Teresa Kowalska ◽  
Mieczysław Sajewicz ◽  
Katarzyna Pytlakowska ◽  
Mariola Bartoszek ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Radical Scavenging ◽  
Cost Effective ◽  
Resonance Spectroscopy ◽  
Dpph Radical ◽  
Dot Blot ◽  
Phenolic Fraction ◽  
Measuring Techniques

Abstract This study presents the results of comparative evaluation of the antioxidant activity of the phenolic fraction exhaustively extracted with aqueous methanol from 18 different thyme (Thymus L.) specimens and species. This evaluation is made with use of the same free radical source (DPPH• radical), three different free radical scavenging models (gallic acid, ascorbic acid, and Trolox), and three different measuring techniques (the dot blot test, UV-Vis spectrophotometry, and electron paramagnetic resonance spectroscopy, EPR). A comparison of the equivalence of these three different measuring techniques (performed with use of hierarchical clustering with Euclidean distance as a similarity measure and Ward's linkage) is particularly important in view of the fact that different laboratories use different antioxidant activity measuring techniques, which makes any interlaboratory comparison hardly possible. The results obtained confirm a semiquantitative equivalence among the three compared methodologies, and a proposal is made of a simple and cost-effective dot blot test that uses the DPPH• radical and provides differentiation of antioxidant activity of herbal matter comparable with the results of the UV-Vis spectrophotometry and EPR.

scholarly journals Phytochemical screening, free radical scavenging, antioxidant activity and phenolic content of Dodonaea viscosa

2012 ◽  
Vol 77 (4) ◽  
pp. 423-435 ◽  
Author(s):  
Tauheeda Riaz ◽  
Athar Abbasi ◽  
A Aziz-Ur-Rehman ◽  
Tayyaba Shahzadi ◽  
Muhammad Ajaib ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Ethyl Acetate ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Total Antioxidant Activity ◽  
Phytochemical Screening ◽  
Dpph Radical ◽  
Dodonaea Viscosa ◽  
Total Antioxidant

The purpose of this study was to evaluate the antioxidant potential of Dodonaea viscosa Jacq. Methanolic extract of the plant was dissolved in distilled water and partitioned with n-hexane, chloroform, ethyl acetate and nbutanol sequentially. Phytochemical screening showed presence of phenolics, flavonoides and cardiac glycosides in large amount in chloroform, ethyl acetate and n-butanol fraction. The antioxidant potential of all these fractions and remaining aqueous fraction was evaluated by four methods: 1,1-Diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, total antioxidant activity, Ferric Reducing Antioxidant Power (FRAP) assay and ferric thiocyanate assay along with determination of their total phenolics. The results revealed that ethyl acetate soluble fraction exhibited highest percent inhibition of DPPH radical as compared to other fractions. It showed 81.14 ? 1.38% inhibition of DPPH radical at a concentration of 60 ?g/ml. The IC50 of this fraction was found to be 33.95 ? 0.58 ?g/ml, relative to butylated hydroxytoluene (BHT), having IC50 of 12.54 ? 0.89 ?g/mL. It also showed highest FRAP value (380.53 ? 0.74 ?M of trolox equivalents) as well as highest total phenolic contents (208.58 ? 1.83 GAE ?g/g) and highest value of inhibition of lipid peroxidation (58.11 ? 1.49% at concentration of 500 ?g/ml) as compared to the other studied fractions. The chloroform fraction showed highest total antioxidant activity i.e.1.078 ? 0.59 (eq. to BHT).

Evaluation of oxidative stability of vegetable oils enriched with herb extracts by EPR spectroscopy

2015 ◽  
Vol 69 (7) ◽  
Author(s):  
Mariola Kozłowska ◽  
Katarzyna Zawada
Keyword(s):  
Free Radical ◽  
Lipid Oxidation ◽  
Vegetable Oils ◽  
Epr Spectroscopy ◽  
Unsaturated Fatty Acids ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Radical Scavenging ◽  
Spin Trapping ◽  
Resonance Spectroscopy ◽  
Herb Extracts

AbstractVegetable oils are important constituents of a healthy diet. Still, unsaturated fatty acids present in vegetable oils are susceptible to oxidation, which leads to undesirable changes in sensory, chemical and nutritional properties of oils. To prevent this problem, antioxidants are applied with herbs and spices being one of the most important sources of natural antioxidants. Electron paramagnetic resonance spectroscopy (EPR) can be used to detect free radicals, which are the short-lived intermediates of lipid oxidation, and to monitor changes in oxidation susceptibility. In this study, the ESR spin trapping technique was used as a potential method for the evaluation of the resistance to free radical formation in rapeseed and sunflower oils enriched with herb extracts. The antioxidant effect of herb extracts on vegetable oils was also investigated by measuring their ability to scavenge DPPH free radical using EPR spectroscopy. The herb extracts generally improved the radical scavenging properties of sunflower and rapeseed oils but their influence on the onset of rapid lipid oxidation as measured by spin-trapping EPR depended on the type of oil and on the extract concentration.

scholarly journals Antioxidant Activity Test of 2,6-bis-(2’-furilidyn)-Cyclohexanone, ; 2,5-bis-(2’-furilidyn)-Cyclopentanone; 1,5-Difuryl-1,4-pentadien-3-one

2010 ◽  
Vol 1 (1) ◽  
pp. 38
Author(s):  
Ismi Rahmawati ◽  
Endang Sri Rejeki ◽  
Sardjiman Sardjiman
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Radical Scavenging ◽  
Positive Control ◽  
Log P ◽  
Dpph Radical ◽  
Curcumin Analog ◽  
Activity Test ◽  
Activity Structure ◽  
Ic50 Value

Antioxidant is an essential compound to keep man’s health due to its function as radical scavenging. Curcumin analog compounds can function as antioxidant (Sardjiman, 2000). The aim of the experiment was to find out the antioxidant activity of 2,.6-bis-(2’-furilidin)-cyclohexanone, 2,.5-bis-(2’furilidin)-cyclopentanone, and 1,.5-difuril-1.4-pentadien-3-one compounds, and the antioxidant activity of each compound against DPPH  radical with IC50 parameter as well as the correlation of compounds structure’s activities against antioxidant. The antioxidant activity of curcumin analog compounds wereas tested against DPPH free radical. The test was conducted in 5 series of concentrations by adding 4.0 ml test solutions with 1.0 ml DPPH. The antioxidant activity against free radical was measured usingwith spectrophotometer at 517 nm wavelength and determined for the IC50 value. The experiment employed rutin as positive control. The result of the experiment showed that curcumin analog compounds have antioxidant activity with IC50 of rutin, 2,.6-bis-(2’-furilidin)-cyclohexanone, 2,.5-bis-(2’furilidin)-cyclopentanone, and 1,.5-difuril-1.4-pentadien-3-one as follows: 4.93 ppm, 22.73 ppm, 20.67 ppm, and 18.80 ppm  respectively. The highest antioxidant activity belonged to 1,.5-difuril-1.4-pentadien-3-one compound which is 18.80 ppm . Correlation of activity structure of the 3 compounds can be seen from the log p parameter and energy space of HOMO-LUMO.Key words: Antioxidant, DPPH, Analog Curcumin

scholarly journals Study of irradiated black pepper antioxidant activity changes 

2004 ◽  
Vol 22 (SI - Chem. Reactions in Foods V) ◽  
pp. S187-S190
Author(s):  
M. Suhaj ◽  
J. Rácová
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Thiobarbituric Acid ◽  
Black Pepper ◽  
Piper Nigrum ◽  
Resonance Spectroscopy

Some antioxidant activities of extracts of irradiated black pepper (Piper nigrum) were evaluated. The ground black pepper was exposed to gamma-irradiation at doses from 5 to 30 kGy. The effect of irradiation on antioxidant properties of black pepper extracts was investigated by these methods: radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, determination of reducing power, thiobarbituric acid reactive substances assay and electron paramagnetic resonance spectroscopy (EPR). Irradiation resulted in a decrease of DPPH antiradical activity of black pepper extracts according to dose of irradiation. Reducing power was not changed by action of irradiation. Very important and sensitive differences in antioxidant activity of irradiated black pepper were investigated by EPR spectrometry and thiobarbituric acid method.

scholarly journals Marine Streptomyces Sp. VITMK1 Derived Pyrrolo [1, 2-A] Pyrazine-1, 4-Dione, Hexahydro-3-(2-Methylpropyl) and Its Free Radical Scavenging Activity

2017 ◽  
Vol 5 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Manickavelu Manimaran ◽  
Krishnan Kannabiran
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Cell Viability ◽  
Tamil Nadu ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Scavenging Activity ◽  
Dpph Radical ◽  
Cell Viability Assay ◽  
Viability Assay

Background: Free radical generation has been proved to be responsible for various cellular diseases. It is necessary to combat free radicals using antioxidants derived from natural sources. Objective: The objective of this study is to evaluate the antioxidant activity of the diketopiperazine compound extracted from Streptomyces sp. VITMK1 isolated from mangrove sediment soil collected from Pichavaram, Tamil Nadu, India. Methods: The antioxidant potential of pyrrolo [1, 2-A] pyrazine-1, 4-dione, hexahydro-3-(2-methylpropyl) (diketopiperazine) extracted from Streptomyces sp. VITMK1 was studied using reducing power assay. The scavenging of 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical and nitric oxide (NO) radical by the compound was also studied. The cytotoxic activity of the compound on RAW 264.7 macrophage cell line was studied using MTT cell viability assay. Results: The compound exhibited strong DPPH radical scavenging activity (72.48±0.32% at 500 µg/mL) and NO radical scavenging activity (73.03±1.02% at 500 µg/mL). MTT cell viability assay revealed that the compound exhibited concentration-dependent cell viability and was observed to be 92% at 125 µg/mL concentration. Conclusion: The antioxidant activity of the diketopiperazine compound extracted from Streptomyces sp. VITMK1 can be probed further to establish its radical scavenging activity.

scholarly journals СИНТЕЗ ТА ДОСЛІДЖЕННЯ АНТИОКСИДАНТНОЇ АКТИВНОСТІ ДЕЯКИХ ПОХІДНИХ НА ОСНОВІ 4-ІМІНОТІАЗОЛІДИН-2-ОНУ

2015 ◽  
Author(s):  
Т. І. Чабан
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Nitrous Acid ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Free Radical Scavenging Activity ◽  
Basic Medium ◽  
Scavenging Activity ◽  
Dpph Radical

<p class="BodyText2" align="center"><strong>Synthesis and antioxidant activity evaluation of </strong><strong>some novel derivatives based on 4-iminothiazolydine-2-one</strong></p><p align="center">T.I. Сhaban</p><p> </p><p align="center">Lviv, Danylo Halytsky Lviv National Medical University</p><p align="center"><strong> </strong></p><p class="a"><strong>Summary</strong>: Thiazolydine derivatives belong to the group of biologically active compounds which are widely used in modern medical chemistry. They were shown to posses the wide range of biological actions.</p><p>4-Imino-2-thiazolydones are relatively unexplored with regard to their preparation synthetic protocols and biological action spectrum in the modern organic and pharmaceutical chemistry as compared to their 2-imino derivatives. Thus the objective of the present work was to synthesize a series of novel 4-imino-2-thiazolydone derivatives as the potential drug-like molecules.  </p><p>3-Aryl-thiazolydine-2,4-dions were firstly prepared using the common synthetic protocol and they were then subjected to thionation reaction with phosphorus pentasulfide leading to the appropriate 3-aryl-4-thioxo-thiazolydin-2-ones obtaining.</p><p>The above-mentioned derivatives were obtained under the conditions similar to that under which well-known 4-thioxo-thiazolydine-2-one (isorhodanine) synthesis was preceded. The synthetic potential of the synthesized compounds allowed 3-aryl-4-thioxo-thiazolydones treatment with 25 % ammonia aqueous solution leading to novel 3-aryl-4-imino-thiazolydine-2-one obtaining not mentioned in the scientific literature. The reaction proceeding was possible taking into account the advantage of thione group significant activity possessing  in 3-aryl-4-thioxo-thiazolydine-2-ones as cyclic thioamides owing to stronger electrophilic properties of thiocarbonyl group carbon atom as compared with carbonyl group in C<sup>4</sup> position of 3-aryl-thiazolydine-2,4-diones, consequently. One of the proofs of synthesized compounds structure was their acidic hydrolysis with 3-aryl-thiazolydine-2,4-ones generation.</p><p>The presence of active methylene group in C<sup>5</sup> position of 3-phenyl-4-imino-thiazolydine-2-one thiazolydine ring provided an entry for aldol condencation carrying out with the respective 3-phenyl-4-imino-thiazolydine-2-one 5-aryliden derivatives generation. We discovered that the high yield of the product could be achieved by introducing the equimolar amounts of  3-phenyl-4-imino-thiazolydine-2-one and appropriate aromatic aldehydes using monoaminoethanol as a catalyst.</p><p>The next stage of our strategy included the core heterocycle further structural modification in its C<sup>5</sup> position. In particular the nitrosylation reaction with nitrous acid was proceeded.  It was found that 3-phenyl-4-imino-thiazolydine-2-one could interact with nitrous acid obtained in its turn under sodium nitrite treatment with hydrochloric acid. Nitrosylation reaction allowed to achiev novel 5-isonitrozo-4-imino-3-phenyl-thiazolydine-2-one which was not mentioned in chemical literature. </p><p> The structures of the obtained compounds were confirmed by <sup>1</sup>H NMR spectroscopy and elemental analysis.</p><p>The antioxidant activity of the novel compounds was determined <em>in vitro</em> on basis of free radical scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical. DPPH radical has found many applications due to its high stability in a methanolic solution and intense purple color. In its oxidized form, the DPPH radical has an absorbance maximum centered at a wavelength about 540 nm. The absorbance decreases when the radical is reduced by antioxidants. Its reduction affords 2,2-diphenyl-1-picrylhydrazine (DPPH-H), or the corresponding anion (DPPH<sup>–</sup>) in basic medium. The DPPH radical acts as a scavenger for other odd-electron species which afford para-substitution products at phenyl rings.</p><p>The pharmacology screening allowed to state that the synthesized compounds had been shown to possess the moderate antioxidant activity. So it may be concluded that    the functionalization of 4-iminotiazolidyn-2-one by its N<sup>3</sup> and C<sup>5</sup> positions did not lead to the free-radical-scavenging activity enhancement. </p>

scholarly journals Composition Analysis by UPLC-PDA-ESI (−)-HRMS and Antioxidant Activity Using Saccharomyces cerevisiae Model of Herbal Teas and Green Teas from Hainan

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2550 ◽  
Author(s):  
Hua Li ◽  
Lanying Wang ◽  
Yanping Luo
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Antioxidant Activity ◽  
Camellia Sinensis ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Antioxidant Compounds ◽  
Total Phenol Content ◽  
Composition Analysis ◽  
Resonance Spectroscopy

Different teas from everywhere are very useful and have been extensively studied. We studied the antioxidant activity of herbal teas and green teas from Hainan, Mallotus oblongifolius Muell. Arg. (MO), Ilex kudingcha C.J. Tseng (KD), Camellia sinensis var. assamica (J. W. Mast.) Kitam. Hainan Dayezhong (DY), and Camellia sinensis (L.) O. Ktze. (produced from Hainan Baisha (BS)). The total phenol content and total flavonoid content from water extracts, resin extracts and fractions of herbal teas and green teas were compared. Later, eight fractions of herbal teas and green teas were subjected to UPLC-PDA-ESI-(−)-HRMS. We determined 1-diphenyl -2-picryl-hydrazyl radical and hydroxyl free radical scavenging activity by electron paramagnetic resonance spectroscopy. We subjected Saccharomyces cerevisiae to hydrogen peroxide, stress and evaluated antioxidant activity of herbal teas and green teas in cellulo. The experiment identified more than 14 potential antioxidant compounds from herbal teas and green teas. The herbal teas and green teas had a clearance rate higher than ferulic acid at the same concentrations. MO best reduced intracellular oxidation levels and increased catalase, glutathione reductase activities, glutathione reduced and glutathione oxidized content. KD had the highest cell survival rate and reduced cell lipid peroxidation. DY best improved superoxide dismutase activity and BS was the most active in the halo test. Therefore, we concluded that MO had stronger antioxidant activity than other herbal teas and green teas from Hainan, especially, which reduce S. cerevisiae oxidative stress under H2O2 stress.

Synthesis, Characterization and Antioxidant Activity of Cooper-Quercetin Complex and Iron-Quercetin Complex

2018 ◽  
Vol 69 (10) ◽  
pp. 2621-2624
Author(s):  
Svetlana Trifunschi ◽  
Melania Florina Munteanu
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Radical Scavenging ◽  
Free Radical Scavengers ◽  
Spectroscopic Techniques ◽  
Dpph Radical ◽  
Radical Scavengers ◽  
Therapeutic Applications ◽  
Flavonoid Quercetin ◽  
Dpph Radical Scavenging

Complexes of cooper (II) and iron (II) with flavonoid quercetin have been synthesized. The structure of compounds has been confirmed by means of UV-Vis and FTIR spectroscopic techniques. The antioxidant activity of the flavonoid complexes has been evaluated by using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. These complexes of flavonoids are much more effective free radical scavengers than the free flavonoids, an aspect which recommends them for further studies on possible therapeutic applications.

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