scholarly journals Verification of the Conditions for Determination of Antioxidant Activity by ABTS and DPPH Assays—A Practical Approach

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 50
Author(s):  
Rafał Wołosiak ◽  
Beata Drużyńska ◽  
Dorota Derewiaka ◽  
Małgorzata Piecyk ◽  
Ewa Majewska ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Reaction Times ◽  
Natural Antioxidants ◽  
Activity Assay ◽  
Reaction Conditions ◽  
Stable Radicals ◽  
Complex Manner ◽  
Assay Conditions

The ABTS and DPPH methods are among the most popular assays of antioxidant activity determination. Attempts to adapt them to different analytes and the search for the highest values of antioxidant activity has resulted in a large variety of assay conditions to be presented in the literature, including the way the measurement is made. This makes it difficult to relate the results to real oxidation systems, and often makes it impossible to compare them. Such a comparison is limited in advance by the use of stable radicals that do not exist in nature and that react differently from those generated in food or in vivo. Therefore, it is important to introduce measures aimed at standardizing the conditions of the activity assay, including reaction time and several reaction environments suitable for testing different groups of compounds. In this study, we used natural antioxidants of various structures: phenolic acids, flavonoids, peptides and corresponding amino acids, ascorbic acid and α-tocopherol, and also synthetic analogues of selected compounds. The curves of dependence of the measured absorbance on the concentration of antioxidants were described, the ranges of linearity were determined, and the value of the error made when reading in various ranges of dependencies was estimated. We also determined and compared the activity values using two popular methods (IC50 and TEAC), taking into account different environments and reaction times. Based on the collected data, recommendations were formulated regarding the reaction conditions adapted to the studies of individual groups of antioxidants, and unified reaction times were proposed. Taking into account the state before reaching the equilibrium of antioxidants reacting in a complex manner, this approach may introduce a simplified reference to the competing reaction that occurs in reality.

scholarly journals Comparative Characteristics of Determination of Antioxidant Activity of Sea Buckthorn Fruits by Various Methods

2019 ◽  
Vol 8 (4) ◽  
pp. 48-52
Author(s):  
O. V. Trineeva
Keyword(s):  
Antioxidant Activity ◽  
Medicinal Plant ◽  
Plant Material ◽  
Natural Antioxidants ◽  
Sea Buckthorn ◽  
In Vitro Tests ◽  
Medicinal Plant Material

Introduction. Recently, much attention has been paid to the primary assessment of the pharmacological effect of various drugs using in vivo and in vitro tests. It is known that such a medicinal plant as sea buckthorn, in its phytochemical composition is rich in natural antioxidants: carotenoids, tocopherols, flavonoids, ascorbic acid, etc. In some publications there is information about the antioxidant activity of sea buckthorn and fatty oil based on them. However, information on the comparative characteristics of the use of various methods for determining the antioxidant activity of this type of medicinal plant material and the results obtained are not found in the scientific literature.Aim. The aim of this work was a comparative determination of the antioxidant activity of medicinal plant material of buckthorn fruits of various species of buckthorn.Materials and methods. The total antioxidant activity of water and water-alcohol extracts from the fruits of sea buckthorn fruits was determined using various techniques recommended in the literature. The antioxidant activity of the extracts was determined by permanganometric titration, in vitro inhibition of adrenaline autooxidation, and also in a biological model, Parametium caudatum cell culture.Results and discussion. The effect of the extractant polarity on the value of antioxidant activity was studied. It was found that the highest content of antioxidants in the extraction is observed when using 96 % ethanol as an extractant.Conclusion. Using three methods, the prospects of using sea buckthorn fruits and preparations based on them as a source of antioxidants are shown. 

scholarly journals Phenolic Composition and Antioxidant Activity of Plants Belonging to the Cephalaria (Caprifoliaceae) Genus

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 952
Author(s):  
Małgorzata Chrząszcz ◽  
Barbara Krzemińska ◽  
Rafał Celiński ◽  
Katarzyna Szewczyk
Keyword(s):  
Antioxidant Activity ◽  
Lung Diseases ◽  
Antioxidative Activity ◽  
Biological Activities ◽  
Natural Antioxidants ◽  
Antioxidant Effect ◽  
In Vivo Studies ◽  
Phenolic Composition

The genus Cephalaria, belonging to the Caprifoliaceae family, is a rich source of interesting secondary metabolites, including mainly saponins which display a variety of biological activities, such as immunomodulatory, antimicrobial and hemolytic effects. Besides these compounds, flavonoids and phenolic acids were identified in Cephalaria species. Cephalaria is employed in traditional medicine e.g., to cure cardiac and lung diseases, rheumatism, and regulate menstruation. In this review we focus on the phenolic compound composition and antioxidative activity of Cephalaria species. The antioxidant effect can be explained by flavonoids present in all parts of these plants. However, future efforts should concentrate more on in vitro and in vivo studies and also on clinical trials in order to confirm the possibility of using these plants as natural antioxidants for the pharmacology, food or cosmetic industries.

scholarly journals ANTIMICROBIAL AND ANTIOXIDANT EFFECT OF NATURAL EXTRACTS FROM LEAVES, ROOT, STEM AND FLOWERS OF BACCHARIS LATIFOLIA FROM ECUADOR

2020 ◽  
pp. 78-84
Author(s):  
FAVIAN BAYAS-MOREJON ◽  
ANGELICA TIGRE ◽  
RIVELINO RAMON ◽  
DANILO YANEZ
Keyword(s):  
Antimicrobial Activity ◽  
Antioxidant Activity ◽  
Potassium Phosphate ◽  
Natural Antioxidants ◽  
Butylated Hydroxytoluene ◽  
Penicillin G ◽  
Diffusion Method ◽  
E Coli ◽  
Antibacterial And Antioxidant Activity

Objective: The increase in chronic and degenerative diseases and the use of synthetic antioxidants such as (butylated hydroxyanisole (BHA) or butylated hydroxytoluene (BHT)) are being restricted because they can be considered carcinogenic. Therefore, there is a growing interest in the search for natural antioxidants, especially from plants, due to their content in different bioactive compounds, such as antioxidants and antimicrobials. To evaluate the antibacterial and antioxidant activity of Baccharislatifolia extracts. Methods: For the determination of the antimicrobial activity of extracts of leaves, root, stem and flowers of Baccharislatifolia (Bl), the disk plate diffusion method was used, the strains of Listeria, Salmonella and E. coli were studied; antibiotics Penicillin G and Ciprofloxacin were the controls. For the antioxidant activity, a solution of H2O2 (Abs at 230 nm) was prepared in Potassium Phosphate Monobasic-Sodium Hydroxide buffer. Results: The antimicrobial activity against Listeria and Salmonella, showed that the extracts of leaves and flowers were more effective with inhibition zones>15 mm and>20 mm respectively. In front of E. coli, the extracts of flowers and stem were the best with zones>7.0 mm. Antibiotics studied inhibited the development of Listeria and Salmonella. However, E. coli isolates were resistant. In the antioxidant activity, the flower extract of Bl in 60 mg/ml presents a higher effect with 47.25%. Conclusion: Bl extracts from leaves and flowers were more efficient both in their antimicrobial and antioxidant capacity.

scholarly journals New Developments in the Synthesis of EMICORON

2018 ◽  
Vol 7 (3) ◽  
pp. 22 ◽  
Author(s):  
Massimo Pitorri ◽  
Marco Franceschin ◽  
Ilaria Serafini ◽  
Alessandro Ciccòla ◽  
Claudio Frezza ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Growth And Development ◽  
Reaction Times ◽  
Preclinical Studies ◽  
Antitumor Activities ◽  
Reaction Conditions ◽  
New Developments ◽  
Work Up ◽  
First Time

This paper reports on the modification of two synthetic steps in the usual protocol used for obtaining EMICORON. EMICORON is a benzo[ghi]perylen-diimide, which was synthesized for the first time in our laboratory in 2012, and has shown to have in vivo antitumor activities that interferes with the tumor growth and development using a multi-target mechanism of action. The provided modifications, which involved the reaction times, the reaction conditions, and the work-up procedures, allowed the global yield of the process to be increased from 28% to about 40%. Thus, this new procedure may be more suitable for recovering higher amounts of EMICORON to be used in further preclinical studies.

In vitro and in vivo determination of antioxidant activity and mode of action of isoquercitrin and Hyptis fasciculata

Phytomedicine ◽  
2009 ◽  
Vol 16 (8) ◽  
pp. 761-767 ◽  
Author(s):  
C.G. Silva ◽  
R.J. Raulino ◽  
D.M. Cerqueira ◽  
S.C. Mannarino ◽  
M.D. Pereira ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Mode Of Action

scholarly journals Antioxidant Activity Test of Effervescent Granules Morinda citrifolia L Leaf Extract with DPPH Free Radical Absorption Method

2021 ◽  
Vol 5 (4) ◽  
pp. 365-368
Author(s):  
Muthmainah Tuldjanah ◽  
Niluh Puspita Dewi ◽  
Dian Rahmawati
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Leaf Extract ◽  
Natural Antioxidants ◽  
Morinda Citrifolia ◽  
Absorption Method ◽  
Immersion Method ◽  
Activity Test ◽  
Ic50 Values

Morinda citrifolia. L leaf is a plant that has the potential as an antioxidant due to the presence of compounds in the form of flavonoids and other phenolic compounds that can function as natural antioxidants. In connection with this, research was carried out to Morinda citrifolia. L formulate leaf extract in the form of effervescent granules. Morinda citrifolia leaf extract was macerated with ethanol 96% as solvent. Phytochemical screening showsthat the extract contains flavonoids, tannins, saponins and alkaloids. The extract was formulated with various concentrations of F1 (20%), F2 (25%), F3 (4%). Determination of antioxidant activity using the DPPH free radical immersion method. The results showed that the concentration in the granules influenced antioxidant activity with IC50 values of 109.05 ppm, 101.33 ppm and 73.28 ppm, respectively

scholarly journals SKRINING FITOKIMIA DAN UJI AKTIVITAS ANTIOKSIDAN EKSTRAK BIJI ADAS (Foeniculum vulgare) MENGGUNAKAN METODE DPPH

2013 ◽  
Vol 13 (2) ◽  
pp. 110
Author(s):  
Idza N Sastrawan ◽  
Meiske Sangi ◽  
Vanda Kamu
Keyword(s):  
Antioxidant Activity ◽  
Natural Antioxidants ◽  
Seed Extract ◽  
Phytochemical Screening ◽  
Activity Assay ◽  
Foeniculum Vulgare ◽  
Fecl3 Solution ◽  
Dpph Method ◽  
Chemical Content ◽  
Keywords Antioxidants

SKRINING FITOKIMIA DAN UJI AKTIVITAS ANTIOKSIDAN EKSTRAK BIJI ADAS (Foeniculum vulgare) MENGGUNAKAN METODE DPPH ABSTRAK Telah dilakukan penelitian tentang skrining fitokimia dan uji aktivitas antioksidan ekstrak biji adas. Tujuan dari penelitian ini yaitu melakukan skrining fitokimia untuk mengetahui kandungan senyawa alkaloid, triterpenoid dan steroid, flavonoid, tannin, saponin dan menetukan aktivitas antioksidan dari ekstrak biji adas. Skrining Fitokimia untuk alkaloid ditentukan dengan menggunakan pereaksi Mayer, Dregendorff, Wagner. Triterpenoid dan steroid ditentukan menggunakan Mg bubuk. Senyawa tannin ditentukan dengan larutan FeCl3 1%. Senyawa saponin ditentukan menggunakan aquades. Ekstrak biji adas diperoleh dengan metode soxhletasi menggunakan pelarut petroleum eter dan uji aktivitas antioksidan menggunakan metode               1-1-difenil-2-pikrihidrazil (DPPH).  Hasil penelitian menunjukan kandungan senyawa kimia biji adas positive mengandung senyawa falvonoid, tannin dan saponin, sedangkan untuk senyawa alkaloid, triterpenoid dan steroid memberikan hasil yang negatif. Aktivitas antioksidan dengan 1000; 2000; 3000; 4000; 5000 ppm,  memberikan hasil berturut-turut yaitu 48.99 %, 33.92 %, 5.93 %, 21.23 %, 6.40 %. Aktivitas antioksidan biji adas tertinggi terdapat pada konsentrasi    1000 ppm dengan hasil 48.99 %. Biji adas memiliki persen aktivitas antioksidan yang baik, sehingga dapat didigunakan sebagai salah satu sumber antioksidan alami.   Kata kunci : Antioksidan, Biji adas, DPPH phytochemical screening and antioxidant activity testing of fennel seed extract (foeniculum vulgare) Using the dpph method Abstract Has done research on phytochemical screening and testing fennel seed extract antioxidant activity. The purpose of this study is to determine the phytochemical screening compounds content of alkaloids, triterpenoids and steroids, flavonoids, tannins, saponins and determine the antioxidant activity of extracts of fennel seeds. Phytochemical screening for alkaloids was determined using reagent Mayer, Dregendorff, Wagner. Triterpenoids and steroids were determined using Mg powder. Tannin compounds determined with 1% FeCl3 solution and saponin determined using distilled water. Fennel seed extract obtained by the method soxhletasi using petroleum ether solvent and antioxidant activity assay using method 1-1-diphenyl-2-pikrihidrazil (DPPH). Research has been done showing the chemical content of fennel seeds contain compounds falvonoid positive , tannins and saponins . Antioxidant activity with 1000 ppm , 2000 ppm,    3000 ppm , 4000 ppm , 5000 ppm , respectively yield is 48.99 % , 33.92 % , 5.93 % , 21.23 %, 6.40 %. The highest antioxidant activity of fennel seeds contained 1000 ppm with 48.99 % result. Fennel seeds have a good percent antioxidant activity , so it can didigunakan as a source of natural antioxidants. Keywords : Antioxidants, Fennel seeds, DPPH

Monosaccharide permethylation products for gas chromatography - mass spectrometry: how reaction conditions can influence isomeric ratios

1997 ◽  
Vol 75 (10) ◽  
pp. 1385-1392 ◽  
Author(s):  
Daniel Derbie Asres ◽  
Hélène Perreault
Keyword(s):  
Mass Spectrometry ◽  
Methyl Iodide ◽  
Reaction Times ◽  
Membered Ring ◽  
Gas Chromatography Mass Spectrometry ◽  
Reaction Parameters ◽  
Methylation Analysis ◽  
Reaction Conditions ◽  
Starting Point

Methylation analysis has been widely used for determination of carbohydrate structures by mass spectrometry. Permethylation of monosaccharides yields mixtures of anomeric pyranosides and furanosides. This paper discusses the influence of some of the permethylation reaction parameters on the proportions of isomeric products obtained. The ratios of three five- and six-membered ring products obtained from two permethylated monosaccharides, D-galactose and L-fucose, have been determined as a function of reaction parameters. The method of Ciucanu and Kerek (1) (methyl iodide in dimethyl sulfoxide (DMSO) in the presence of sodium hydroxide (NaOH)) was used as a starting point. The "conventional" method consists of mixing all of the reagents with the substrate and allowing the reaction to proceed with stirring. Both D-galactose and L-fucose under these conditions produced two main permethylated isomers, a furanoside and a pyranoside, along with two other minor isomeric components. We have investigated the effect on the proportion of products obtained of mixing DMSO, substrate, and NaOH for various times prior to the addition of methyl iodide. Results for D-galactose showed that shorter times enhanced the formation of permethylated furanoside isomers, while reducing the proportion of pyranosides. In other sets of experiments, the time and temperature of reaction, following the addition of methyl iodide, were studied. The indication is that 15 min are sufficient to produce complete methylation, with longer reaction times yielding the same results. Again for D-galactose, low reaction temperatures (ca. 10 °C) favored formation of furanoside products. Higher temperatures yielded higher pyranoside/furanoside ratios. Higher quantities of NaOH also favored formation of the main galactopyranoside product. As for L-fucose, the ratio of the main furanoside vs. pyranoside products obtained by permethylation varied in a way similar to permethylated galactoside. Thus, higher temperatures and longer reaction times favored the main fucopyranoside product. Gentler conditions (i.e., shorter reaction times and lower temperatures) significantly favored the formation of the main fucofuranoside product. These results are interesting as they show the possibility of controlling the relative abundance of permethylated isomers of fucose and galactose. They also constitute a warning to chemists who use methylation procedures in their analyses, to the effect that permethylation products may vary considerably if the reaction conditions are not carefully controlled. Keywords: glucose, galactose, fucose, TLC, GC–MS, permethylation, monosaccharides.

The antioxidant activity of Lactic acid bacteria and probiotics: a review

2021 ◽  
Author(s):  
Azita Faraki ◽  
Fatemeh Rahmani
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Activity ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Natural Antioxidants ◽  
Oxidation Reactions ◽  
Synthetic Antioxidants ◽  
In Vivo Models ◽  
Positive Effects

Probiotics and Lactic Acid Bacteria play important roles such as the production of antimicrobial compounds and other metabolites. So they have positive effects on human health. When reactive oxygen species generated in excess or cellular defenses are deficient, biomolecules can be damaged by the oxidative stress process. Various studies have shown that the best way to protect the human body from the effects of oxidation reactions is to avoid them, which can be accomplished by using antioxidants. Due to the damages of synthetic antioxidants, their usage has been discussed. Nowadays natural antioxidants derived from bio-resources have recently gained a lot of attention as a potential replacement for synthetic antioxidants. Probiotic bacteria are thought to defend against oxidative stress by restoring the gut microbiota, according to hypothesis of some scientists. This type of microorganisms indicated their antioxidant activity by producing and increasing antioxidant enzymes, production of secondary metabolites, small hydrolyzed peptides in food, resistance to the presence of hydrogen peroxide, and production of intracellular and extracellular compounds such as Exopolysaccharides. Also, they have shown their positive effect on in vivo models. In conclusion, according to the results of studies, lactic acid bacteria and probiotics are significant sources of natural antioxidants. Therefore, they have important research value and market development potential. Also, it should be noted that the mechanism of antioxidant activity of this group of microorganisms has not been fully investigated, this requires further research.

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