scholarly journals Antioxidant Potential of Aqueous Dispersions of Fullerenes C60, C70, and Gd@C82

2021 ◽  
Vol 22 (11) ◽  
pp. 5838
Author(s):  
Ivan V. Mikheev ◽  
Madina M. Sozarukova ◽  
Dmitry Yu. Izmailov ◽  
Ivan E. Kareev ◽  
Elena V. Proskurnina ◽  
...  

The antioxidant potential (capacity and activity) of aqueous fullerene dispersions (AFD) of non-functionalized C60, C70, and Gd@C82 endofullerene (in micromolar concentration range) was estimated based on chemiluminescence measurements of the model of luminol and generation of organic radicals by 2,2′-azobis(2-amidinopropane) dihydrochloride (ABAP). The antioxidant capacity was estimated by the TRAP method, from the concentration of half-suppression, and from the suppression area in the initial period. All three approaches agree and show that the antioxidant capacity of AFDs increased in the order Gd@C82 < C70 < C60. Mathematical modeling of the long-term kinetics data was used for antioxidant activity estimation. The effect of C60 and C70 is found to be quenching of the excited product of luminol with ABAP-generated radical and not an actual antioxidant effect; quenching constants differ insignificantly. Apart from quenching with a similar constant, the AFD of Gd@C82 exhibits actual antioxidant action. The antioxidant activity in Gd@C82 is 300-fold higher than quenching constants.

2011 ◽  
Vol 23 (2) ◽  
pp. 151-160 ◽  
Author(s):  
Luciana S. Oliveira ◽  
Maria S. M. Rufino ◽  
Carlos F. H. Moura ◽  
Fabio R. Cavalcanti ◽  
Ricardo E. Alves ◽  
...  

This study evaluated the effect of the processing and long-term storage on the antioxidant potential and activity of antioxidant enzymes of frozen purées from six acerola clones. Ripe acerolas from clones BRS 235, BRS 236, BRS 237, BRS 238, II47/1 and BRS 152 were harvested; the pulp was processed, packed in sealed polyethylene plastic bags and stored in a domestic freezer at -18°C for 11 months. Samples of each clone were analyzed on harvest/processing day and every 30 days after for bioactive antioxidant compounds, antioxidant enzyme activity and total antioxidant activity. Acerola purées presented a decrease of non-enzyme antioxidants and an increase of antioxidant enzymes activities, indicatives of a compensatory mechanism between enzymatic and non-enzymatic antioxidants. In acerola purée, anthocyanin and polyphenols are strongly correlated to soluble solids content and vitamin C seems a major contributor to total antioxidant activity. Clone II47/1 had an outstanding performance regarding the antioxidant potential of its purée and the best storage period at -18ºC would be 150 days, for all clones studied.


2018 ◽  
Vol 20 (K7) ◽  
pp. 35-40
Author(s):  
Tam-Dinh Le-Vo ◽  
Cuong Vi Tran

In this study, the antioxidant potential of peptide fractions isolated from the Tra catfish (Pangasius hypophthalmus) by-product-derived hydrolysate using ultrafiltration centrifugal devices with 3 distinct molecular-weight cutoffs (MWCOs) of 5KDa, 10KDa, and 30KDa was investigated. Firstly, the chemical composition of the Tra catfish byproducts was analyzed. The result showed that the Tra catfish by-products contained 58.5% moisture, 33.9% crude protein, 50.1% crude lipid and 15.8% ash (on dry weight basis). Secondly, the effects of enzyme content, hydrolysis time on the antioxidant activity of the hydrolysate were studied using DPPH• (2,2-diphenyl-1-picrylhydrazyl) radical scavenging method (DPPH• SM), and FRAP (ferric reducing antioxidant potential) method. Flavourzyme® 500 MG was used for hydrolysis. The result revealed that the antioxidant activity of the proteolysate reached the peak when the hydrolysis time was 3h, enzyme/substrate (E/S) ratio was 25 U/g protein, hydrolysis temperature was 500C, pH was 7, and the degree of hydrolysis (DH) of the hydrolysate reached 37.4%. Next, the proteolysate was further fractionated using MWCOs of 5KDa, 10KDa, and 30KDa and the peptide fractions were investigated for their antioxidant activity. The result showed that the <5KDa fraction showed strongest antioxidant activity with the 50% DPPH• inhibition concentration (IC50) of 3079.34±75.29 μg/mL and FRAP value of 611.28±4.5 μM Trolox equivalent. The second strongest fraction was 5-10KDa with the IC50 and FRAPS value of 4709.3 ± 222.22 μg/mL and 323.62±2.54 μM Trolox equivalent, respectively. The 10-30KDa fraction showed weakest antioxidant capacity with the IC50 of 5847.73 ± 128.68 μg/mL and FRAP value of 291.4±2.65 μM Trolox equivalent. The antioxidant peptides derived from Tra catfish by-products proteolysate have the potential to be used as natural antioxidant ingredients in pharmaceutical and food industry.


2021 ◽  
Author(s):  
Cristina Jansen-Alves ◽  
Juliana Pereira ◽  
Deborah M. Otero ◽  
Rui Carlos Zambiazi

Abstract Porpuse: Rubus are economically important fruits, being highly valued for their taste and medicinal properties, for which it is estimated that there are between 400 to 700 species but many of them are still unknown by the population. Methods: The literature does not present much information regarding the physicochemical, bioactive composition and antioxidant activity of Rosaceae Rubus rosifolius Smith and for this reason this research was carried out. Results: The fruits presented low content of lipids (7.42%) and ash (0.27%), intermediate values of protein (11.54%), and with considerable content fiber (23.72%) and carbohydrates (59.18%), low acidity, and interesting values of soluble solids. Regarding bioactive compounds, good concentrations of phenolic compounds (289.4 (mg. g− 1 EAG), flavonoids (155 mg100g− 1), anthocyanins (120.11 mg cyanidin-3-glucoside 100g− 1) and phytoene (517.3 mg100g− 1). Conclusion: The wild strawberry showed good antioxidant capacity verified by different methods of analysis. Given the findings of this research, it is observed that this fruit has nutritional and phytochemical potential to be inserted in the human diet and therefore its consumption should be encouraged.


2019 ◽  
pp. 49-59
Author(s):  
Nu Linh Giang Ton ◽  
Thi Hoai Nguyen ◽  
Quoc Hung Vo

Avocado peel has been considered as a potential source of natural antioxidants in which phenolics are among the most important compounds. Therefore, this study aims to optimize the extraction process of phenolics using response surface methodology and evaluate the corresponding antioxidant activity. From the quadratic model, the optimal condition was determined including the ethanol concentration 54.55% (v/v), the solvent/solute ratio 71.82/1 (mL/g), temperature 53.03 oC and extraction time 99.09 min. The total phenolic content and the total antioxidant capacity at this condition with minor modifications were 26,74 ± 0,04 (mg GAE/g DW) and 188.06 ± 1.41 (mg AAE/g DW), respectively. The significant correlation between total phenolic content and total antioxidant capacity was also confirmed. Key words: response surface methodology, central composite rotatable design, total phenolic content, total antioxidant capacity, avocado peel


2020 ◽  
Vol 16 ◽  
Author(s):  
Bhim Bahadur Chaudhari ◽  
Alka Bali ◽  
Ajitesh Balaini

Background: NSAIDs are the most widely prescribed medications worldwide for their anti-inflammatory, antipyretic, and analgesic effects However, their chronic use can lead to several adverse drug events including GI toxicity. The selective COX-2 inhibitors developed as gastro-sparing NSAIDs also suffer from serious adverse effects which limit their efficacy. Objective: Local generation of reactive oxygen species is implicated in NSAID-mediated gastric ulceration and their combination with H2 antagonists like famotidine reduces the risk of ulcers. The objective of this work was to design and synthesize novel methanesulphonamido isoxazole derivatives by hybridizing the structural features of NSAIDs with those of antiulcer drugs (ranitidine, famotidine, etc.) to utilize a dual combination of anti-inflammatory activity and reducing (antioxidant) potential. Method: The designing process utilized three dimensional similarity studies and utilized an isoxazole core having a potential for anti-inflammatory as well as radical scavenging antioxidant activity. The compounds were assayed for their antiinflammatory activity in established in vivo models. The in vitro antioxidant activity was assessed in potassium ferricyanide reducing power (PFRAP) assay employing ascorbic acid as the standard drug. Results: Compounds (5, 6, 9 and 10) showed anti-inflammatory activity comparable to the standard drugs and were also found to be non-ulcerogenic at the test doses. Compounds 6-10 exhibited good antioxidant effect in the concentration range of 1.0-50.0 µmol/ml. The test compounds were also found to comply with the Lipinski rule suggesting good oral absorption. Conclusion: A new series of isoxazole based compounds is being reported with good anti-inflammatory activity coupled with antioxidant potential as gastro-sparing anti-inflammatory agents.


2020 ◽  
Vol 16 ◽  
Author(s):  
Benedetta Bocchini ◽  
Bruna Goldani ◽  
Fernanda S.S. Sousa ◽  
Paloma T. Birmann ◽  
Cesar A. Brüning ◽  
...  

Background: Quinoline derivatives have been attracted much attention in drug discovery and synthetic derivatives of these scaffolds present a range of pharmacological activities. Therefore, organoselenium compounds are valuable scaffolds in organic synthesis because their pharmacological activities and their use as versatile building blocks for regio-, chemio-and stereoselective reactions. Thus, the synthesis of selenium-containing quinolines has great significance, and their applicability range from simple antioxidant agents, to selective DNA-binding and photocleaving agents. Objective: In the present study we describe the synthesis and antioxidant activity in vitro of new 7-chloroN(arylselanyl)quinolin-4-amines 5 by the reaction of 4,7-dichloroquinoline 4 with (arylselanyl)-amines 3. Methods: For the synthesis of 7-chloro-N(arylselanyl)quinolin-4-amines 5, we performed the reaction of (arylselanyl)- amines 3 with 4,7-dichloroquinoline 4 in the presence of Et3N at 120 °C in a sealed tube. The antioxidant activities of the compounds 5 were evaluated by the following in vitro assays: 2,2- diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferric ion reducing antioxidant power (FRAP), nitric oxide (NO) scavenging and superoxide dismutase-like activity (SOD-Like). Results: 7-Chloro-N(arylselanyl)quinolin-4-amines 5a-d has been synthesized in yields ranging from 68% to 82% by the reaction of 4,7-dichloroquinoline 4 with arylselanyl-amines 3a-d using Et3N as base, at 120 °C, in a sealed tube for 24 hours and tolerates different substituents, such as -OMe and -Cl, in the arylselanyl moiety. The obtained compounds 5a-d presented significant results with respect to the antioxidant potential, which had effect in the tests of inhibition of radical’s DPPH, ABTS+ and NO, as well as in the test that evaluates the capacity (FRAP) and in the superoxide dismutase-like activity assay (SOD-Like). It is worth mentioning that 7-chloro-N(arylselanyl)quinolin-4-amine 5b presented excellent results, demonstrating a better antioxidant capacity when compared to the others. Conclusion: According to the obtained results 7-chloro-N(arylselanyl)quinolin-4-amines 5 were synthesized in good yields by the reaction of 4,7-dichloroquinoline with arylselanyl-amines and tolerates different substituents in the arylselanyl moiety. The tested compounds presented significant antioxidant potential in the tests of inhibition of DPPH, ABTS+ and NO radicals, as well as in the FRAP and superoxide dismutase-like activity assays (SOD-Like).


2019 ◽  
Vol 18 (10) ◽  
pp. 1417-1424 ◽  
Author(s):  
Emilia Naydenova ◽  
Diana Wesselinova ◽  
Svetlana Staykova ◽  
Ivan Goshev ◽  
Ljubomir Vezenkov

Background: Based on the structure of RC-121 (D-Phe-c (Cys-Tyr-D-Trp-Lys-Val-Cys)-Thr-NH2, - synthetic derivatives of somatostatin), some analogs were synthesized and tested for in vitro cytotoxic and antioxidant activity. Objectives: The new analogs were modifyed at position 5 with Dap (diaminopropanoic acid), Dab (diaminobutanoic acid) and Orn and at position 6 with the unnatural amino acids Tle (t-leucine). Methods: The in vitro cytotoxic effects of the substances were investigated against a panel of human tumor cell lines HT-29 (Human Colorectal Cancer Cell Line), MDA-MB-23 (Human Breast Cancer Cell Line), Hep G-2 (Human Hepatocellular Carcinoma Cell Line) and HeLa (cervical cancer cell line). The antioxidant capacities were tested by ORAC (Oxygen Radical Antioxidant Capacity) and HORAC (Hydroxyl Radical Averting Capacity) methods. Results: All substances expressed significantly higher antioxidant capacity by comparison with galic acid and Trolox. All substances showed considerable antioxidant capacity as well. Compound 2T (D-Phe-c(Cys-Tyr-DTrp- Dap-Tle-Cys)-Thr-NH2)had the highest antioxidant effect. The compound 4T (D-Phe-c(Cys-Tyr-D-Trp- Orn-Tle-Cys)-Thr-NH2) displayed antiproliferative effect on HeLa cells with IC50 30 µM. The peptide analog 3T (D-Phe-c(Cys-Tyr-D-Trp-Lys-Tle-Cys)-Thr-NH2) exerted the most pronounced inhibition on the cell vitality up to 53%, 56% and 65% resp. against MDA-MB-23, Hep G-2, HeLa in the higher tested concentration. Conclusion: The somatostatin analogs showed moderate influence on the vitality of different tumor cells and could be used in changing their pathology.


2020 ◽  
Vol 10 (2) ◽  
pp. 158-162 ◽  
Author(s):  
Humaira Yasmeen Gondal ◽  
Roshan Zamir ◽  
Muhammad Nisar ◽  
Muhammad Iqbal Choudhary

Background: The genus Verbascum is well documented for its antioxidant potential but Verbascum sinaiticum is comparatively less studied plant. The current study was carried out to search for antioxidant nutraceuticals from this species. Objective: To explore the antioxidant potential of Verbascum sinaiticum and to identify its active constituents. Methods: The methanolic extract of air-dried aerial part of the Verbascum sinaiticum was partitioned with hexane, chloroform and ethyl acetate. The water-soluble part of ethyl acetate afforded six phenylethanoid glycosides by repeated chromatography over Sephadex LH-20, silica gel and ODS columns. Antioxidant activity of solvent extracts and isolated constituents were evaluated by DPPH, ABTS and FRAP assays. Results: Six phenylethanoid glycosides was isolated and characterized as Verbascoside, Eukovoside, Martynoside, Jionoside D, Campneoside I and Campneoside II, from the most active fraction. Conclusion: Verbascum sinaiticum demonstrated prospective antioxidant activity. The watersoluble part of EtOAc (WSEAE) was found the most active extract whereas Verbascoside was identified as the most potent constituent. All isolated compounds exhibited significant antioxidant activity whereas their synergistic effect was found prominent in the parent fraction.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1255
Author(s):  
Sofia C. Lourenço ◽  
Débora A. Campos ◽  
Ricardo Gómez-García ◽  
Manuela Pintado ◽  
M. Conceição Oliveira ◽  
...  

Pineapple peel still contains an important amount of phenolic compounds and vitamins with valuable antioxidant activity. In this way, the aim of this study was the recovery of the bioactive compounds from pineapple peel using environmentally friendly and low-cost techniques, envisaging their application in food products. From the solid-liquid extraction conditions tested, the one delivering an extract with higher total phenolic content and antioxidant capacity was a single extraction step with a solvent-pineapple peel ratio of 1:1 (w/w) for 25 min at ambient temperature, using ethanol-water (80–20%) as a solvent. The resulting extract revealed a total phenolic content value of 11.10 ± 0.01 mg gallic acid equivalent (GAE)/g dry extract, antioxidant activity of 91.79 ± 1.98 µmol Trolox/g dry extract by the DPPH method, and 174.50 ± 9.98 µmol Trolox/g dry extract by the FRAP method. The antioxidant rich extract was subjected to stabilization by the spray drying process at 150 °C of inlet air temperature using maltodextrin (5% w/w) as an encapsulating agent. The results showed that the antioxidant capacity of the encapsulated compounds was maintained after encapsulation. The loaded microparticles obtained, which consist of a bioactive powder, present a great potential to be incorporated in food products or to produce bioactive packaging systems.


Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 234 ◽  
Author(s):  
Yili Hong ◽  
Zening Wang ◽  
Colin J. Barrow ◽  
Frank R. Dunshea ◽  
Hafiz A. R. Suleria

Stone fruits, including peach (Prunus persica L.), nectarine (Prunus nucipersica L.), plum (Prunus domestica L.) and apricot (Prunus armeniaca L.) are common commercial fruits in the market. However, a huge amount of stone fruits waste is produced throughout the food supply chain during picking, handling, processing, packaging, storage, transportation, retailing and final consumption. These stone fruits waste contain high phenolic content which are the main contributors to the antioxidant potential and associated health benefits. The antioxidant results showed that plum waste contained higher concentrations of total phenolic content (TPC) (0.94 ± 0.07 mg gallic acid equivalents (GAE)/g) and total flavonoid content (TFC) (0.34 ± 0.01 mg quercetin equivalents (QE)/g), while apricot waste contained a higher concentration of total tannin content (TTC) (0.19 ± 0.03 mg catechin equivalents (CE)/g) and DPPH activity (1.47 ± 0.12 mg ascorbic acid equivalents (AAE)/g). However, nectarine waste had higher antioxidant capacity in ferric reducing-antioxidant power (FRAP) (0.98 ± 0.02 mg AAE/g) and total antioxidant capacity (TAC) (0.91 ± 0.09 mg AAE/g) assays, while peach waste showed higher antioxidant capacity in 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assay (0.43 ± 0.09 mg AAE/g) as compared to other stone fruits waste. Qualitative and quantitative phenolic analysis of Australian grown stone fruits waste were conducted by liquid chromatography coupled with electrospray-ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS) and HPLC-photodiode array detection (PDA). The LC-ESI-QTOF-MS/MS result indicates that 59 phenolic compounds were tentatively characterized in peach (33 compounds), nectarine (28), plum (38) and apricot (23). The HPLC-PDA indicated that p-hydroxybenzoic acid (18.64 ± 1.30 mg/g) was detected to be the most dominant phenolic acid and quercetin (19.68 ± 1.38 mg/g) was the most significant flavonoid in stone fruits waste. Hence, it could be concluded that stone fruit waste contains various phenolic compounds and have antioxidant potential. The results could support the applications of these stone fruit wastes in other food, feed, nutraceutical and pharmaceutical industries.


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