scholarly journals Design and Antioxidant Properties of Bifunctional 2H-Imidazole-Derived Phenolic Compounds—A New Family of Effective Inhibitors for Oxidative Stress-Associated Destructive Processes

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6534
Author(s):  
Elena L. Gerasimova ◽  
Elena R. Gazizullina ◽  
Maria V. Borisova ◽  
Dinara I. Igdisanova ◽  
Egor A. Nikiforov ◽  
...  

The synthesis of inhibitors for oxidative stress-associated destructive processes based on 2H-imidazole-derived phenolic compounds affording the bifunctional 2H-imidazole-derived phenolic compounds in good-to-excellent yields was reported. In particular, a series of bifunctional organic molecules of the 5-aryl-2H-imidazole family of various architectures bearing both electron-donating and electron-withdrawing substituents in the aryl fragment along with the different arrangements of the hydroxy groups in the polyphenol moiety, namely derivatives of phloroglucinol, pyrogallol, hydroxyquinol, including previously unknown water-soluble molecules, were studied. The structural and antioxidant properties of these bifunctional 5-aryl-2H-imidazoles were comprehensively studied. The redox transformations of the synthesized compounds were carried out. The integrated approach based on single and mixed mechanisms of antioxidant action, namely the AOC, ARC, Folin, and DPPH assays, were applied to estimate antioxidant activities. The relationship “structure-antioxidant properties” was established for each of the antioxidant action mechanisms. The conjugation effect was shown to result in a decrease in the mobility of the hydrogen atom, thus complicating the process of electron transfer in nearly all cases. On the contrary, the conjugation in imidazolyl substituted phloroglucinols was found to enhance their activity through the hydrogen transfer mechanism. Imidazole-derived polyphenolic compounds bearing the most electron-withdrawing functionality, namely the nitro group, were established to possess the higher values for both antioxidant and antiradical capacities. It was demonstrated that in the case of phloroglucinol derivatives, the conjugation effect resulted in a significant increase in the antiradical capacity (ARC) for a whole family of the considered 2H-imidazole-derived phenolic compounds in comparison with the corresponding unsubstituted phenols. Particularly, conjugation of the polyphenolic subunit with 2,2-dimethyl-5-(4-nitrophenyl)-2H-imidazol-4-yl fragment was shown to increase ARC from 2.26 to 5.16 (104 mol-eq/L). This means that the considered family of compounds is capable of exhibiting an antioxidant activity via transferring a hydrogen atom, exceeding the activity of known natural polyphenolic compounds.

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Abdelkader Basli ◽  
Stéphanie Soulet ◽  
Nassima Chaher ◽  
Jean-Michel Mérillon ◽  
Mohamed Chibane ◽  
...  

There are numerous studies indicating that a moderate consumption of red wine provides certain health benefits, such as the protection against neurodegenerative diseases. This protective effect is most likely due to the presence of phenolic compounds in wine. Wine polyphenolic compounds are well known for the antioxidant properties. Oxidative stress is involved in many forms of cellular and molecular deterioration. This damage can lead to cell death and various neurodegenerative disorders, such as Parkinson’s or Alzheimer’s diseases. Extensive investigations have been undertaken to determine the neuroprotective effects of wine-related polyphenols. In this review we present the neuroprotective abilities of the major classes of wine-related polyphenols.


Author(s):  
L. P. Nilova ◽  
S. M. Malyutenkova

The results of studies of the biochemical composition and antioxidant properties of nuts sold in the consumer market of St. Petersburg were presented in the work. The objects of research were kernels of nuts: sweet almonds, hazelnuts, cashews, walnuts. Total Soxhlet lipids, fatty acid composition, vitamin E, fractional composition of tocopherols and phytosterols, total phenolic compounds and flavonoids, antioxidant activity by FRAP with ferric chloride, o-phenanthroline and Triton X 100 were determined in nuts. Nuts varied in lipid content (42.6–65.4%) with a predominance of unsaturated fatty acids from 80.4 to 92.4 relative%. Oleic acid prevailed in the fatty acids of almonds, hazelnuts and cashews, while linoleic acid prevailed in walnuts. Walnuts contained the highest amount of polyunsaturated fatty acids. The antioxidant properties of nuts were formed by a complex of water and fat-soluble antioxidants. Fat-soluble antioxidants included vitamin E with a predominance of ?-tocopherol in the kernels of sweet almonds and hazelnuts, ?-tocopherol - in walnuts and cashews. Only sweet almond kernels contained all the tocopherol fractions. ?- and ?-tocopherols were absent in hazelnut lipids, while ?-tocopherols were absent in cashews and walnuts. ?-sitosterol, campesterol and stigmasterol with a predominance of ?-sitosterol were identified in the composition of phytosterols in all nut kernels. Water-soluble antioxidants are mainly represented by phenolic compounds, the amount of which varies widely depending on the type of nuts: cashews


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Vasilina Sergeeva ◽  
Olga Kraevaya ◽  
Elizaveta Ershova ◽  
Larisa Kameneva ◽  
Elena Malinovskaya ◽  
...  

Oxidative stress is a major issue in a wide number of pathologies (neurodegenerative, cardiovascular, immune diseases, and cancer). Because of this, the search for new antioxidants is an important issue. One of the potential antioxidants that has been enthusiastically discussed in the past twenty years is fullerene and its derivatives. Although in aqueous solutions fullerene derivatives have shown to be antioxidants, their properties in this regard within the cells are controversially discussed. We have studied two different water-soluble fullerene C60 and C70 derivatives on human embryonic lung fibroblasts at a wide range of concentrations. Both of them cause a decrease in cellular ROS at short times of incubation (1 hour). Their prolonged action, however, is fundamentally different: derivative GI-761 causes secondary oxidative stress whereas derivative VI-419-P3K keeps ROS levels under control values. To gain a better understanding of this effect, we assessed factors that could play a role in the response of cells to fullerene derivatives. Increased ROS production occurred due to NOX4 upregulation by GI-761. Derivative VI-419-P3K activated the transcription of antioxidant master regulator NRF2 and caused its translocation to the nucleus. This data suggests that the antioxidant effect of fullerene derivatives depends on their chemical structure.


Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4371
Author(s):  
Weronika Adach ◽  
Jerzy Żuchowski ◽  
Barbara Moniuszko-Szajwaj ◽  
Malgorzata Szumacher-Strabel ◽  
Anna Stochmal ◽  
...  

Background: The Paulownia Clone in Vitro 112, known as oxytree or oxygen tree, is a hybrid clone of the species Paulownia elongata and Paulownia fortunei (Paulowniaceae). The oxytree is a fast-growing hybrid cultivar that can adapt to wide variations in edaphic and climate conditions. In this work, Paulownia Clone in Vitro 112 leaves were separated into an extract and four fractions (A–D) differing in chemical content in order to investigate their chemical content using LC-MS analysis. The extract and fractions were also evaluated for their anticoagulant and antioxidant properties in a human plasma in vitro. Results: The Paulownia leaf extract contained mainly phenolic compounds (e.g., verbascoside), small amounts of iridoids (e.g., aucubin or 7-hydroxytometoside) and triterpenoids (e.g., maslinic acid) were also detected. Our results indicate that the extract and fractions have different effects on oxidative stress in human plasma treated with H2O2/Fe in vitro, which could be attributed to differences in their chemical content. For example, the extract and all the fractions, at the two highest concentrations of 10 and 50 µg/mL, significantly inhibited the plasma lipid peroxidation induced by H2O2/Fe. Fractions C and D, at all tested concentrations (1–50 µg/mL) were also found to protect plasma proteins against H2O2/Fe-induced carbonylation. The positive effects of fraction C and D were dependent on the dose. Conclusions: The extract and all four fractions, but particularly fractions C and D, which are rich in phenolic compounds, are novel sources of antioxidants, with an inhibitory effect on oxidative stress in human plasma in vitro. Additionally, the antioxidant potential of fraction D may be associated with triterpenoids.


2014 ◽  
Vol 80 (18) ◽  
pp. 5874-5881 ◽  
Author(s):  
Arunava Pradhan ◽  
José Paulo Pinheiro ◽  
Sahadevan Seena ◽  
Cláudia Pascoal ◽  
Fernanda Cássio

ABSTRACTThe water-soluble polyhydroxyfullerene (PHF) is a functionalized carbon nanomaterial with several industrial and commercial applications. There have been controversial reports on the toxicity and/or antioxidant properties of fullerenes and their derivatives. Conversely, metals have been recognized as toxic mainly due to their ability to induce oxidative stress in living organisms. We investigated the interactive effects of PHF and cadmium ions (Cd) on the model yeastSaccharomyces cerevisiaeby exposing cells to Cd (≤5 mg liter−1) in the absence or presence of PHF (≤500 mg liter−1) at different pHs (5.8 to 6.8). In the absence of Cd, PHF stimulated yeast growth up to 10.4%. Cd inhibited growth up to 79.7%, induced intracellular accumulation of reactive oxygen species (ROS), and promoted plasma membrane disruption in a dose- and pH-dependent manner. The negative effects of Cd on growth were attenuated by the presence of PHF, and maximum growth recovery (53.8%) was obtained at the highest PHF concentration and pH. The coexposure to Cd and PHF decreased ROS accumulation up to 36.7% and membrane disruption up to 30.7% in a dose- and pH-dependent manner. Two mechanisms helped to explain the role of PHF in alleviating Cd toxicity to yeasts: PHF decreased Cd-induced oxidative stress and bound significant amounts of Cd in the extracellular medium, reducing its bioavailability to the cells.


Biomolecules ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1266
Author(s):  
Noelia Carballeda Sangiao ◽  
Susana Chamorro ◽  
Sonia de Pascual-Teresa ◽  
Luis Goya

Cocoa is a rich source of polyphenols, especially flavanols and procyanidin oligomers, with antioxidant properties, providing protection against oxidation and nitration. Cocoa phenolic compounds are usually extracted with methanol/ethanol solvents in order to obtain most of their bioactive compounds; however, aqueous extraction seems more representative of the physiological conditions. In this study, an aqueous extract of cocoa powder has been prepared and chemically characterized, and its potential protective effect against chemically-induced oxidative stress has been tested in differentiated human neuroblastoma SH-SY5Y cells. Neuronal-like cultured cells were pretreated with realistic concentrations of cocoa extract and its major monomeric flavanol component, epicatechin, and then submitted to oxidative stress induced by a potent pro-oxidant. After one hour, production of reactive oxygen species was evaluated by two different methods, flow cytometry and in situ fluorescence by a microplate reader. Simultaneously, reduced glutathione and antioxidant defense enzymes glutathione peroxidase and glutathione reductase were determined and the results used for a comparative analysis of both ROS (reactive oxygen species) methods and to test the chemo-protective effect of the bioactive products on neuronal-like cells. The results of this approach, never tested before, validate both analysis of ROS and indicate that concentrations of an aqueous extract of cocoa phenolics and epicatechin within a physiological range confer a significant protection against oxidative insult to neuronal-like cells in culture.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Fuhao Wang ◽  
Lu Huang ◽  
Xingxing Yuan ◽  
Xiaoyan Zhang ◽  
Luping Guo ◽  
...  

Abstract This study aimed to investigate the proximate and phytochemicals present in seeds of 24 mung bean (Vigna radiate L.) genotypes from four provinces of China for estimating their nutritional and antioxidant properties. Proximate analysis of mung bean genotypes revealed that starch, protein, fat, ash and water-soluble polysaccharide ranged from 39.54–60.66, 17.36–24.89, 4.24–12.18, 2.78–3.53 and 1.99–2.96 g/100 g respectively. The five principal fatty acids detected in mung beans were stearic acid, palmitic acid, linoleic acid, oleic acid, and linolenic acid. The contents of insoluble-bound phenolic compounds, soluble phenolic compounds, and flavonoids ranged from 0.78 to 1.5 mg GAE g− 1, 1.78 to 4.10 mg GAE g− 1, and 1.25 to 3.52 mg RE g− 1, respectively. The black seed coat mung bean genotype M13 (Suheilv 1) exhibited highest flavonoid and phenolic contents which showed strong antioxidant activity. Two flavonoids (vitexin and isovitexin) and four phenolic acids (caffeic, syringic acid, p-coumaric, and ferulic acids) were identified by HPLC. Vitexin and isovitexin were the major phenolic compounds in all mung bean genotypes. The content of soluble phenolic compounds had positive correlation with DPPH (r2 = 0.713) and ABTS (r2 = 0.665) radical scavenging activities. Principal component analysis indicated that the first two principal components could reflect most details on mung bean with a cumulative contribution rate of 66.1%. Twenty-four mung bean genotypes were classified into four groups based on their phenolic compounds contents and antioxidant activities. The present study highlights the importance of these mung bean genotypes as a source of nature antioxidant ingredient for the development of functional foods or a source of health promoting food. Graphical Abstract


2014 ◽  
Vol 111 (11) ◽  
pp. 1985-1991 ◽  
Author(s):  
Marziyeh Ashoori ◽  
Ahmad Saedisomeolia

Oxidative stress is involved in the development of many chronic diseases. One of the main factors involved in oxidative stress reduction is increased antioxidant potential. Some nutrients such as vitamin C, vitamin E and carotenoids are known to act as antioxidants; however, riboflavin is one of the neglected antioxidant nutrients that may have an antioxidant action independently or as a component of the glutathione redox cycle. Herein, studies that have examined the antioxidant properties of riboflavin and its effect on oxidative stress reduction are reviewed. The results of the reviewed studies confirm the antioxidant nature of riboflavin and indicate that this vitamin can protect the body against oxidative stress, especially lipid peroxidation and reperfusion oxidative injury. The mechanisms by which riboflavin protects the body against oxidative stress may be attributed to the glutathione redox cycle and also to other possible mechanisms such as the conversion of reduced riboflavin to the oxidised form.


2019 ◽  
pp. 127-137 ◽  
Author(s):  
Любовь (Lyubov') Николаевна (Nikolaevna) Скрыпник (Skrypnik) ◽  
Алина (Alina) Андреевна (Andreevna) Курашова (Kurashova)

The antioxidant properties of fruits, flowers, leaves, bark (or stem) of elderberry (Sambucus nigra L.), red elderberry (Sambucus racemosa L.) and dwarf elder (Sambucus ebulus L.) were investigated. The total content of anthocyanins and total phenolic compounds content by using of Folin-Ciocalteu assay were determined spectrophotometrically. The total content of water-soluble antioxidants was investigated by amperometric method. The antioxidant activity (AOA) of plant extracts was measured using DPPH (1,1-diphenyl-2-picrylhydrazyl) radical, ABTS (2,2’azinobis(3)ethylbenzthiazoline-6- sulfonic acid) radical and FRAP (ferric reducing antioxidant power) assays. It was established that the fruits of plants of the genus Sambucus L. were characterized by the maximum level of all studied antioxidants. High content of anthocyanins and phenolic compounds was determined in the leaves of elderberry and dwarf elder. The flowers of these elderberry species were distinguished by a high total content of water-soluble antioxidants. The highest antioxidant activity was observed in fruits extracts in comparison with other parts of the plant. Higher antioxidant activity was identified in the extract of the fruits of elderberry and dwarf elder than of the red elderberry fruits. The most optimal method for evaluating the antioxidant activity of elder extracts was the FRAP assay, which showed the highest correlation between AOA and individual antioxidant components, compared to DPPH and ABTS assays. Comparative analysis of antioxidant content and antioxidant activity of various plant parts of three elderberry species showed that the most promising sources of biologically active substances with antioxidant properties are fruits and flowers of elderberry and dwarf elder.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Mohamed A. Hamzawy ◽  
Ezzeldein S. M. El-Denshary ◽  
Nabila S. Hassan ◽  
Fathia A. Mannaa ◽  
Mosaad A. Abdel-Wahhab

This study was conducted to evaluate the total phenolic compounds, the antioxidant properties, and the hepatorenoprotective potential of Calendula officinalis extract against aflatoxins (AFs-) induced liver damage. Six groups of male Sprague-Dawley rats were treated for 6 weeks included the control; the group fed AFs-contaminated diet (2.5 mg/kg diet); the groups treated orally with Calendula extract at low (CA1) and high (CA2) doses (500 and 1000 mg/kg b.w); the groups treated orally with CA1 and CA2 one week before and during AFs treatment for other five weeks. The results showed that the ethanol extract contained higher phenolic compounds and posses higher 1,1-diphenyl 1-2-picryl hydrazyl (DPPH) radical scavenging activity than the aqueous extract. Animals fed AFs-contaminated diet showed significant disturbances in serum biochemical parameters, inflammatory cytokines, and the histological and histochemical pictures of the liver accompanied by a significant increase in malondialdehyde (MDA) and a significant decrease in superoxide dismutase (SOD) and glutathione peroxidase (GPx) in liver. Calendula extract succeeded to improve the biochemical parameters, inflammatory cytokines, decreased the oxidative stress, and improved the histological pictures in the liver of rats fed AFs-contaminated diet in a dose-dependent manner. It could be concluded that Calendula extract has potential hepatoprotective effects against AFs due to its antioxidant properties and radical scavenging activity.


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