scholarly journals SYNTHESIS AND STUDY OF PROPERTIES OF DERIVATIVES OF PHLOROGLUCINOLMETHYLVIOLOGEN AS ANTIOXIDANT ADDITIVES TO OILS

2019 ◽  
Vol 62 (8) ◽  
pp. 132-138
Author(s):  
Karina G. Alexanyan ◽  
Olga A. Stokolos ◽  
Samir Yu. Salmanov ◽  
Anna V. Naletova ◽  
Eduard R. Mikhailov ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Metal Ion ◽  
Antioxidant Properties ◽  
Alkyl Radicals ◽  
1H Nuclear Magnetic Resonance ◽  
Antioxidant Additives ◽  
Metal Deactivator ◽  
Hindered Phenols ◽  
High Antioxidant Activity ◽  
Derivatives Of

At the present time there is a need to search for new organic compounds with pronounced antioxidant activity. In this work, we studied indicators of antioxidant stability of the compounds obtained by the modification of the phloroglucinol and methylviologen, and identified the basic principles of the synthesis of antioxidant additives. Moreover, the synthesized compounds can act as metal deactivator. These deactivators are phenolic compounds containing functional groups, for example, the iminogroup, which lead to the deactivation of the metal ion through the formation of stable complexes. A literature review showed that in order to achieve it, iminogroup should be introduced. It is worth mentioning that it can reduce the solubility of the compound in hydrocarbon. To solve this problem, it is necessary to introduce higher alkyl radicals to the molecule. In this paper, a number of antioxidant additives such as aminophenols were synthesized. To obtain the antioxidants of the type of spatially hindered phenols, also able to bind cations of metals in chelate complexes, that is, potentially able to be metal deactivators, a series of Schiff bases were synthesized via an intermediate product of the acylation. In the course of the work the corresponding substituted triamine benzenes from phloroglucinol methyl and phloroglucinol were obtained. The resulting compounds exhibit high antioxidant activity. The synthesized compounds were characterized via 1H nuclear magnetic resonance, IR spectroscopy and mass spectrometry. The trials carried out with compounds on the basis of phloroglucinol and methylviologen showed that some of them have good antioxidant properties and can be recommended for the further more details investigation as well as for synthesis of an array with a similar structure with various substituting groups.

scholarly journals The Effect of Rosa spinosissima Fruits Extract on Lactic Acid Bacteria Growth and Other Yoghurt Parameters

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1167
Author(s):  
Marek Szołtysik ◽  
Alicja Z. Kucharska ◽  
Anna Sokół-Łętowska ◽  
Anna Dąbrowska ◽  
Łukasz Bobak ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Lactic Acid ◽  
Phenolic Compounds ◽  
Antioxidant Properties ◽  
Positive Influence ◽  
Quality Characteristics ◽  
Additive Concentration ◽  
Bacteria Growth ◽  
High Antioxidant Activity ◽  
Positive Effect

The aim of the study was to evaluate the effect of purified extract from Rosa spinosissima fruits on the quality characteristics and antioxidant properties of yoghurt. The extract, added to yoghurt at a concentration of 0.1% and 0.2%, contained high quantities of phenolic compounds and exhibited high antioxidant activity due to the presence of anthocyanins flavan-3-ols, flavonols and ellagitannins. Yoghurt physicochemical properties, microbiology and antioxidant properties were evaluated after 1, 7 and 14 days of storage at a temperature of 4 °C. The data revealed a positive influence of rose preparation on yoghurt’s microflora and on its other properties. The highest count of traditional yoghurt microflora was observed in samples with 0.2% of extract. Its addition had a positive effect on the yoghurts’ color, giving them a characteristic pink color of an intensity dependent on additive concentration. It also significantly affected the yoghurts’ antioxidant properties, which were stable during storage, as well as the content of the introduced phenolic compounds.

ANTIOXIDANT ACTIVITY OF AMINOTHIAZOL HYDROXYCOUMARIN DERIVATIVES

2013 ◽  
Vol 12 (06) ◽  
pp. 1350058 ◽  
Author(s):  
DAVOOD FARMANZADEH ◽  
MEYSAM NAJAFI
Keyword(s):  
Antioxidant Activity ◽  
Gas Phase ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Experimental Studies ◽  
Structure Parameters ◽  
Coumarin Derivatives ◽  
Polar Solvents ◽  
B3lyp Method ◽  
High Antioxidant Activity

In this work, the antioxidant properties of the series of 10 aminothiazol hydroxyl coumarin derivatives have been investigated with DFT/B3LYP method. For these antioxidants all reaction enthalpies related to HAT, SPLET, SET-PT mechanisms were calculated in the gas phase and polar solvents. Based on calculated reaction enthalpies (BDE, IP and PA values) the derivations 2, 3 and 4 have the highest antioxidant activity among the studied compounds. Calculated results show that derivations 7, 5 and 6 have the lowest antioxidant activity. The observed theoretical trends for antioxidant activities of studied compounds were similar to trends of previous experimental studies that OH50, TAC50, IC50, CE50 values have been used as a benchmark for measuring the antioxidant properties of these compounds. These results can be useful in synthesis of novel aminothiazol hydroxycoumarin derivatives with high antioxidant activity. Calculated results show that BDE, PA and IP values of studied derivations have linear dependence with structure parameters such as R( O – H ), q( O ) and E HOMO . These observed linear dependences can be useful in synthesis of novel aminothiazol hydroxyl coumarin derivatives with high antioxidant activity. For studied compounds, results indicated that the SPLET and HAT mechanisms represent the thermodynamically preferred mechanism both, in solvent and the gas phase.

scholarly journals Novel agonists of melatonin receptors as promising hypotensive and neuroprotective agents for therapy of glaucoma

2017 ◽  
Vol 63 (1) ◽  
pp. 75-80 ◽  
Author(s):  
N.B. Chesnokova ◽  
O.V. Beznos ◽  
N.A. Lozinskaya ◽  
M.S. Volkova ◽  
E.V. Zaryanova ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Intraocular Pressure ◽  
Superoxide Anion ◽  
Anion Radical ◽  
Antioxidant Properties ◽  
Hypotensive Effect ◽  
Melatonin Receptors ◽  
Neuroprotective Agents ◽  
High Antioxidant Activity ◽  
Therapeutic Tools

Melatonin is a pineal hormone that has a capacity to lower intraocular pressure; it exhibits neuroprotective and antioxidant properties that make it possible to use melatonin in the therapy of glaucoma. Analogs of melatonin having affinity to melatonin receptors are promising candidates for application as antiglaucomatous drugs. Chemical modification of the melatonin structure can in-crease efficiency, bioavailability and selectivity of these analogs. We have designed and synthe-sized a number of new 2-oxindole derivatives – ligands of melatonin MT3 subtype receptors that displayed ability to lower intraocular pressure in normotensive rabbits and high antioxidant activity against hydroxyl radical and superoxide anion-radical. The antioxidant activity of new ligands was several times higher than one of melatonin that makes them prospective therapeutic tools for the diseases that include oxidative stress. The maximal hypotensive effect of analogs was comparable to that of melatonin itself but prolonged. Combination of these properties gives an opportunity of using the presented melatonin analogs in complex therapy of glaucoma.

scholarly journals Antioxidant Properties of Casein Phosphopeptides (CPP) and Maillard-Type Conjugated Products

Antioxidants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 648
Author(s):  
Huiying Zhang ◽  
Soichiro Nakamura ◽  
David D. Kitts
Keyword(s):  
Antioxidant Activity ◽  
Metal Ion ◽  
Fenton Reaction ◽  
Soybean Lecithin ◽  
Antioxidant Properties ◽  
Aqueous System ◽  
Binding Assays ◽  
Site Specific ◽  
Casein Phosphopeptides ◽  
Casein Phosphopeptide

A casein phosphopeptide (CPP) fraction derived from tryptic hydrolysis of bovine casein was evaluated for antioxidant activity. Conjugations or mixtures of CPP with polysaccharide, galactomannan (Gal), or xyloglucan (Xyl) were prepared to evaluate potential enhancement of CPP antioxidant activity. The effect of calcium was also investigated. The CPP preparation alone was effective at scavenging hydroxyl radicals and sequestering Fe2+ to protect against Fenton reaction-induced deoxyribose oxidation in non-site-specific (up 63.3% inhibition) and site-specific (up 32.1% inhibition) binding assays, respectively. CPP also effectively quenched 2,2’-azinobis-3-ethylbenzothiazoline-6-sulfonic acid radicals (ABTS•+) to an extent of 67.6% scavenging in an aqueous system. In a soybean lecithin liposome system, CPP exhibited effective protection against peroxyl radical-induced liposomal peroxidation (38.3% of control in terms of rate of propagation). Conjugating CPP with Gal or Xyl polysaccharides using Maillard reaction conditions significantly reduced activity in the Fenton reaction-deoxyribose assays, while exhibiting no effect on the antioxidant activity of native CPP in both the ABTS and liposome assays, respectively. These results represent comparative antioxidant capacity of the native CPP and associated conjugates in phases that varied in relative hydrophilic and hydrophobic character. We conclude that CPP has the potential to act as both a primary and secondary antioxidant by displaying transition metal ion sequestering activity and free radical quenching activity. Improvements in antioxidant activity of CPP by Maillard-type conjugation with Xyl or Gal were relatively small and model-specific.

scholarly journals Enhanced Antioxidant Activity of Ursolic Acid by Complexation with Copper (II): Experimental and Theoretical Study

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 264
Author(s):  
Mariola Samsonowicz ◽  
Monika Kalinowska ◽  
Kamila Gryko
Keyword(s):  
Antioxidant Activity ◽  
Molecular Orbital ◽  
Ursolic Acid ◽  
Metal Ion ◽  
Chemical Reactivity ◽  
Antioxidant Properties ◽  
Molar Ratio ◽  
Antioxidant Power ◽  
Ferric Reducing Antioxidant Power ◽  
Lowest Unoccupied Molecular Orbital

The copper (II) complex of ursolic acid (Cu(II) UA) was synthesized and discussed in terms of its infrared, UV–visible spectra, quantum-chemical calculations at B3LYP/6-31G(d) level and antioxidant capacity. The copper (II) complex was stable in methanolic solution with the molar ratio metal:ligand 1:1. The data obtained by FT-IR confirmed the metal ion coordination through the carboxylate anion. The antioxidant properties of ursolic acid and its complex with Cu were discussed on the basis of energy of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and values of chemical reactivity parameters. The antiradical properties of ursolic acid and the Cu (II) complex were examined against DPPH• and HO• radicals, and the ferric reducing antioxidant power (FRAP) was examined. The Cu(II) complex showed higher antioxidant activity than ursolic acid, i.e., in DPPH• assay, the EC50 for UA was 47.0 mM, whereas, for Cu(II), UA EC50 = 19.5 mM; the FRAP value for UA was 20.8 µMFe2+, and 35.4 µMFe2+ for Cu(II) UA (compound concentration 3 mM). Although there was no distinct difference in the antioxidant activity against HO• between these two chemicals, they were both better HO• scavengers than DPPH• and showed different kinetics in the reaction with DPPH•.

scholarly journals A Facile Electrochemical Analysis to Determine Antioxidant Activity of Bee Pollen

2013 ◽  
Vol 14 ◽  
pp. 31-38 ◽  
Author(s):  
Abdelkrim Rebiai ◽  
Touhami Lanez
Keyword(s):  
Antioxidant Activity ◽  
Cyclic Voltammetry ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Electrochemical Analysis ◽  
Polyphenolic Compounds ◽  
Bee Pollen ◽  
Cyclic Voltammetry Method ◽  
High Antioxidant Activity ◽  
Phenolic And Flavonoid

The aim of this study was to determine the phenolic and flavonoid content, and antioxidant properties of tow samples of bee pollen harvested from Algeria. The content of total polyphenolic compounds, flavonoids, and antioxidant activity by the cyclic voltammetry method were determined. The contents of polyphenolic compounds was 22.68 mg/g for the pollen from Blida and 21,9 mg/g for Tipaza pollen. High antioxidant activities were found for the cyclic voltammetry method, with values that ranged from 22,3 to 27,63 mg of AAE·g–1 pollen. The bee pollen of Blida showed high antioxidant activity probably due to the high content of polyphenolic compounds present in pollen.

scholarly journals Potency of endophytic fungi from Nauclea orientalis L. as antioxidant producer

2021 ◽  
Vol 27 (1) ◽  
pp. 34-40
Author(s):  
Elisa Nurnawati ◽  
Hary Widjajanti ◽  
Vivi Hendra Sutandar ◽  
Maulida Harwati ◽  
Eka Amelia ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Secondary Metabolites ◽  
Host Plant ◽  
Secondary Metabolite ◽  
Endophytic Fungi ◽  
Antioxidant Properties ◽  
Antioxidant Compounds ◽  
Genetic Transfer ◽  
High Antioxidant Activity ◽  
Antioxidant Agent

Nauclea orientalis L. is widely distributed in Indonesia. Secondary metabolites such as flavonoids, polyphenols, and saponins are abundant in the bark of N. orientalis L. These compounds have the potential to act as antioxidants. Endophytic fungi, through genetic transfer and coevolution, can produce the same metabolites as their host plant. As a result, understanding the potential of endophytic fungi from N. orientalis L. to produce antioxidant compounds that can be developed is critical. According to the findings of this study, twelve isolates have the potential to produce secondary metabolites with antioxidant properties. Three isolates had high antioxidant activity: DB2 was identified as Aspergillus minisclerotigenes with an IC50 of 21 g/mL containing tannins, terpenes, and flavonoids, AB3 as Colletotrichum perseae with an IC50 of 31 g/mL containing tannins and terpenoids, and AB1 as Diaporthe tulliensis with an IC50 of 48 g/mL containing tannins. The secondary metabolite group has the potential to be developed into an antioxidant agent

scholarly journals Assessment of antioxidant properties of membrane ultrafiltration peptides from mungbean meal protein hydrolysates

2018 ◽  
Author(s):  
Chanikan Sonklin ◽  
Natta Laohakunjit ◽  
Orapin Kerdchoechuen
Keyword(s):  
Molecular Weight ◽  
Antioxidant Activity ◽  
Amino Acid ◽  
Metal Ion ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Scavenging Activity ◽  
Antioxidant Power ◽  
Ferric Reducing Antioxidant Power ◽  
Peptide Fractions

Background Bioactive peptides can prevent damage associated with oxidative stress in the human body when consumed regularly. Recently year, peptides have attracted immense interest because of their beneficial functional properties, safety and little or no side effects when used at high concentration. Most antioxidant peptide has small size less than 1 kDa and contains high proportion of hydrophobic amino acid. Particularly Tyr, Leu, Ala, Ile, Val, Lys, Phe, Cys, Met and His exhibited high antioxidant activity. Mungbean protein contain high abundance of protein and hydrophobic amino acid contents, investigating its bioactivity is an important aspect of adding value to this by-product obtained from a growing industry. Therefore, the objectives of this study were to optimize the conditions used to generate MMPH with antioxidant activity form bromelain and to investigate the antioxidant activities of each molecular weight peptide fraction. Methods Response Surface Methodology (RSM) was used for screening the optimal conditions to produce Mungbean meal protein hydrolysate (MMPH). After that optimal MMPH was fractionated using ultrafiltration membranes with different molecular weight (MW) distribution. Crude-MMPH and four peptide fractions were investigated for five antioxidant activities: DPPH scavenging activity, Hydroxyl scavenging activity, Superoxide scavenging activity, Ferric reducing antioxidant power and metal ion chelation activity. Results The optimal condition of crude-MMPH production was 12 % (w/w) of bromelain and hydrolysis time for 12 h. The EC50 of DPPH was the highest for the F4 peptide fraction (MW<1 kDa) at 0.5320 mg/mL. Metal ion chelating activity was generally weak, except for the F4 that had a value of 43.94% at a protein concentration of 5 mg/mL. The F4 also exhibited high hydroxyl and superoxide radical scavenging activities (54 and 65.1%), but poor activity for ferric reducing antioxidant power (0.102 mM Fe2+/mg protein) compared to other peptide fractions and crude-MMPH. Molecular weight and amino acid were the main factors that determined the antioxidant activities of these peptide fractions. Results show that F4 have high antioxidant potentials. Discussion The lowest MW Fraction (less than 1 kDa) showed the highest DPPH activity, superoxide-, hydroxyl-scavenging activity and metal chelation activity. On the other hand, this fraction had poor ferric reducing power. This showed that low molecular weight has an important effect on antioxidant activities. According to the mechanism of the reaction, the potential of antioxidant activity was divided into two main groups: hydrogen atom transfer (HAT) and single electron transfer (SET). Therefore, this finding suggests that the antioxidant mechanism of peptides obtained mungbean could react with many species of free radicals by multiple mechanisms. Mungbean meal peptide can be developed into multiple functional foods which possess both antioxidant properties and aroma/taste.

Extraction of bioactive proteins from seeds (corn, sorghum, and sunflower) and sunflower byproduct: enzymatic hydrolysis and antioxidant properties

2020 ◽  
Vol 16 ◽  
Author(s):  
Danielle Maria Fernandes do Prado ◽  
Adrielle Borges de Almeida ◽  
Josemar Gonçalves Oliveira Filho ◽  
Cassia Cristina Fernandes Alves ◽  
Mariana Buranelo Egea ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Enzymatic Hydrolysis ◽  
Food Systems ◽  
Protein Extraction ◽  
Proteolytic Enzymes ◽  
Antioxidant Properties ◽  
Natural Antioxidants ◽  
Extraction Methods ◽  
Degree Of Hydrolysis ◽  
High Antioxidant Activity

Background: Food proteins have benefits for human health, which justifies their production and use. In this context, we highlight the use of seeds and byproduct that would be otherwise discarded to produce protein extracts and hydrolyzed proteins generating opportunities to reduce environmental impacts Objective: This work aimed to use different extraction methods to obtain protein extracts from seeds (corn, sorghum, sunflower) and sunflower byproduct to determine their antioxidant activity, and apply different proteolytic enzymes in the hydrolysis of sunflower byproduct Method: The seeds of corn, sorghum, and sunflower, and sunflower byproduct were ground to produce flour and the protein extracts were prepared using five different methods. The bioactivity of fractions was analyzed by different methods (ABTS, DPPH, and FRAP) to evaluate antioxidant activity Results: The most effective methods, which resulted in higher protein extraction and antioxidant activity, were those in which NH4HCO3 (5 mM, pH 8.0) and H2O/C2H6O (2:3) were used in the extraction. The highest protein contents were 797.9, 303.8, and 11296.5 μg/g, and the highest antioxidant activity was 34417.5, 9732.6, and 47473.1 μg TE/g from Soxhlet and Bligh and Dyer defatted extractions for sunflower seed, and sunflower byproduct, respectively. Regarding enzymatic hydrolysis, sunflower byproduct was the substrate that presented the highest degree of hydrolysis (11.06%) when Neutrase® enzyme was used. Enzymatic hydrolysis increased antioxidant activity in the hydrolyzed proteins, approximately 20.0% using Neutrase® and 22.3% using Flavourzyme® treatments. Conclusion: The protein extracts and the hydrolyzed proteins exhibited high antioxidant activity, demonstrating great potential for use as natural antioxidants in food systems

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