Effect of Metal Ions (Cu2+/Fe2+) on the Antioxidant Activity of L-Ascorbic Acid-Glycine Model System

2011 ◽  
Vol 396-398 ◽  
pp. 28-31
Author(s):  
Cheng Yi Lei ◽  
Da Zhai Zhou ◽  
Rong Zhao ◽  
Qi Hui Deng ◽  
Ai Nong Yu ◽  
...  

The influence of Cu2+, Fe2+ on the Maillard reaction were studied by heating L-ascorbic(ASA) and glycine (Gly) solutions adjusted to pH 5 at 120±2°C for 140 min in an oil bath. The presence of metals affected the intensity of browning and intermediate products, as monitored by absorbance at 420 nm and absorbance at 294 nm, sharply increased with the increase of metal concentrations applied (0.000M, 0.005M, 0.010M, 0.015M, 0.020M). Thereafter, slight increases were observed up to 0.020M. Antioxidative activity of all MRPs derived from ASA-Gly model systems sharply increased at 0.015M (P < 0.05) and slightly changes in activity were found with increasing metal concentrations up to 0.020M. Moreover, radical-scavenging activity correlated well with browning intensity and absorbance at 294 nm.

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1135B-1135
Author(s):  
Basavaraj Girennavar ◽  
Bhimanagouda Patil ◽  
Guddadarangavvanahally Jayaprakasha

Antioxidant activity is widely used as a parameter to characterize different plant materials for potential health benefits. This activity is related with compounds capable of protecting a biological system against the harmful effect of reactions that can cause excessive oxidation, involving reactive oxygen and nitrogen species (RONS). There has been growing interest in the beneficial health effects of consuming fruits and vegetables. Mainly, the presence of lycopene, ascorbic acid, and phenolic antioxidants is believed to have the protective mechanism. The free radical-scavenging activities of grapefruit extract of `Rio Red', `Marsh White', and commercial juice were extracted with different solvents, such as hexane, ethyl acetate, and chloroform. The dried extracts were screened for their radical scavenging activity using the α,α -diphenyl-β-picrylhydrazyl (DPPH) method. The ethyl acetate extracts of commercial juice and `Marsh White' were found to possess more radical scavenging activity compared with the other two extracts. However, chloroform extracts of `Rio Red' grapefruit were the most active, which may be ascribed to the presence of more lycopene. Furthermore, the antioxidant capacity of `Rio Red' and `Marsh White' extracts was assayed through the phosphomolybdenum method and expressed as equivalent to ascorbic acid (μmol·g-1 of the extract). The order of antioxidant capacity for `Rio Red' extracts was found to be hexane > chloroform > ethyl acetate, while the order for `Marsh White' was chloroform > hexane > ethyl acetate. The results indicate that the extent of antioxidant activity of the extract is in accordance with the amount of lycopene/phenolics present in that extract; commercial juice and `Rio Red' may provide a good source of antioxidants.


2019 ◽  
Vol 20 (19) ◽  
pp. 4735 ◽  
Author(s):  
Anja Harej ◽  
Andrijana Meščić Macan ◽  
Višnja Stepanić ◽  
Marko Klobučar ◽  
Krešimir Pavelić ◽  
...  

The novel 4-substituted 1,2,3-triazole L-ascorbic acid (L-ASA) conjugates with hydroxyethylene spacer as well as their conformationally restricted 4,5-unsaturated analogues were synthesized as potential antioxidant and antiproliferative agents. An evaluation of the antioxidant activity of novel compounds showed that the majority of the 4,5-unsaturated L-ASA derivatives showed a better antioxidant activity compared to their saturated counterparts. m-Hydroxyphenyl (7j), p-pentylphenyl (7k) and 2-hydroxyethyl (7q) substituted 4,5-unsaturated 1,2,3-triazole L-ASA derivatives exhibited very efficient and rapid (within 5 min) 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging activity (7j, 7k: IC50 = 0.06 mM; 7q: IC50 = 0.07 mM). In vitro scavenging activity data were supported by in silico quantum-chemical modelling. Thermodynamic parameters for hydrogen-atom transfer and electron-transfer radical scavenging pathways of anions deprotonated at C2-OH or C3-OH groups of L-ASA fragments were calculated. The structure activity analysis (SAR) through principal component analysis indicated radical scavenging activity by the participation of OH group with favorable reaction parameters: the C3-OH group of saturated C4-C5(OH) derivatives and the C2-OH group of their unsaturated C4=C5 analogues. The antiproliferative evaluation showed that p-bromophenyl (4e: IC50 = 6.72 μM) and p-pentylphenyl-substituted 1,2,3-triazole L-ASA conjugate (4k: IC50 = 26.91 μM) had a selective cytotoxic effect on breast adenocarcinoma MCF-7 cells. Moreover, compound 4e did not inhibit the growth of foreskin fibroblasts (IC50 > 100 μM). In MCF-7 cells treated with 4e, a significant increase of hydroxylated hypoxia-inducible transcription factor 1 alpha (HIF-1α) expression and decreased expression of nitric oxide synthase 2 (NOS2) were observed, suggesting the involvement of 4e in the HIF-1α signaling pathway for its strong growth-inhibition effect on MCF-7 cells.


Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 17
Author(s):  
Eva Havránková ◽  
Nikola Čalkovská ◽  
Tereza Padrtová ◽  
Jozef Csöllei ◽  
Radka Opatřilová ◽  
...  

A series of 1,3,5-triazine derivatives, incorporating aminobenzenesulfonamide, aminoalcohol/phenol, piperazine, chalcone, or stilbene structural motifs, were evaluated as potential antioxidants. The compounds were prepared by using step by step nucleophilic substitution of chlorine atoms in starting 2,4,6-trichloro-1,3,5-triazine. Reactions were catalyzed by Cu(I)-supported on a weakly acidic resin. The radical scavenging activity was determined in terms of %inhibition activity and IC50, using the ABTS method. Trolox and ascorbic acid (ASA) were used as standards. In the lowest used concentration 1 × 10−4 M, the %inhibition activity at time 0 min was comparable with both standards at least for 10 compounds. After 60 min compounds 1, 2, 9 and 25 showed nearly twice %inhibition (73.44–87.09%) in comparison with standards (Trolox = 41.49%; ASA = 31.07%). Values of IC50 correlated with %inhibition activity. For compounds 1, 2, 9 and 25 values of IC50 in time 60 min (17.16–27.78 μM) were 5 times lower than IC50 of both standards (Trolox = 178.33 μM; ASA = 147.47 μM). Based on these results, the presented 1,3,5-triazine derivatives and their analogs have a high potential in the treatment of illnesses caused or related to oxidative stress.


1998 ◽  
Vol 44 (9) ◽  
pp. 1931-1936 ◽  
Author(s):  
P Barton Duell ◽  
David L Wheaton ◽  
Amy Shultz ◽  
Hien Nguyen

Abstract Melatonin has been suggested as a potent antioxidant that may protect against development of atherosclerosis and cancer; however, these effects are unproven and controversial. The antioxidant capacity of melatonin was tested in comparison with α-tocopherol, ascorbic acid, and the melatonin precursors tryptophan and serotonin, by measuring inhibition of metal ion-mediated and human macrophage-mediated oxidation of LDL. Melatonin had weak antioxidant activity that was detectable only at concentrations 10 000- to 100 000-fold higher than physiologic concentrations. These results were comparable with published data showing that the radical scavenging activity of melatonin requires markedly supraphysiologic concentrations. In contrast, α-tocopherol was 50- to 100-fold more potent and was efficacious at physiologic concentrations. Ascorbic acid and tryptophan also were active at physiologic concentrations and were significantly more potent than melatonin. In summary, extremely supraphysiologic concentrations of melatonin had only weak antioxidant activity, which was surpassed by α-tocopherol, ascorbic acid, and tryptophan.


Antioxidants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1148 ◽  
Author(s):  
Hak-Dong Lee ◽  
Ji Hyun Kim ◽  
Qi Qi Pang ◽  
Pil-Mun Jung ◽  
Eun Ju Cho ◽  
...  

This study determined acteoside and its content in Abeliophyllum distichum via HPLC/UV and LC/ESI-MS to obtain insights into the potential use of this plant as an antioxidant agent. Moreover, 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl (•OH), and O2− radical scavenging activity assays were performed to assess in vitro antioxidative activity. The DPPH, •OH, and O2− radical scavenging activities of A. distichum leaf EtOH extracts at a 250 μg/mL concentration were 88.32%, 94.48%, and 14.36%, respectively, whereas those of stem extracts at the same concentration were 88.15%, 88.99%, and 15.36%, respectively. The contents of acteoside in A. distichum leaves and stems were 162.11 and 29.68 mg/g, respectively. Acteoside was identified as the main antioxidant compound in A. distichum leaves, which resulted in DPPH, •OH, and O2− radical scavenging activities of 82.84%, 89.46%, and 30.31%, respectively, at a 25 μg/mL concentration. These results indicate that A. distichum leaves and stems containing the antioxidant acteoside can be used as natural ingredients for functional and nutritional supplements.


2011 ◽  
Vol 396-398 ◽  
pp. 1645-1651 ◽  
Author(s):  
Qiu Ping Zhong ◽  
Yong Cheng Li

In this study, total polyphenols content (TPC) and ascorbic acid content (AAC) in CAW were quantified. Total antioxidant activity, reducing capacity, and free radical scavenging activity of CAW were assayed. The TPC and AAC were 160 mg GAE /100ml and 132 mg/100 ml,respectivity. CAW exhibited effective antioxidant activities in the employed in vitro experiments, including total antioxidant activity, reducing capacity, and free radical scavenging activity, which indicates that phenolic compounds and ascorbic acid may play a key role in the antioxidant function of CAW.


Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1787 ◽  
Author(s):  
Eva Havránková ◽  
Nikola Čalkovská ◽  
Tereza Padrtová ◽  
Jozef Csöllei ◽  
Radka Opatřilová ◽  
...  

A series of 1,3,5-triazine analogues, incorporating aminobenzene sulfonamide, aminoalcohol/phenol, piperazine, chalcone, or stilbene structural motifs, were evaluated as potential antioxidants. The compounds were prepared by using step-by-step nucleophilic substitution of chlorine atoms in starting 2,4,6-trichloro-1,3,5-triazine. Reactions were catalyzed by Cu(I)-supported on a weakly acidic resin. The radical scavenging activity was determined in terms of %inhibition activity and EC50, using the ABTS method. Trolox and ascorbic acid (ASA) were used as standards. In the lowest concentration 1 × 10−4 M, the %inhibition activity values at 0 min were comparable with both standards at least for 10 compounds. After 60 min, compounds 5, 6, 13, and 25 showed nearly twice %inhibition (73.44–87.09%) in comparison with the standards (Trolox = 41.49%; ASA = 31.07%). Values of EC50 at 60 min (17.16–27.78 μM) were 5 times lower for compounds 5, 6, 13, and 25 than EC50 of both standards (trolox = 178.33 μM; ASA = 147.47 μM). Values of EC50 correlated with %inhibition activity. Based on these results, the presented 1,3,5-triazine analogues have a high potential in the treatment of illnesses caused or related to oxidative stress.


HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1000A-1000
Author(s):  
G.K. Jayaprakasha ◽  
Clark Wilson ◽  
Bhimanagouda S. Patil

Consumption of fruits and vegetables has been associated with reduced risk of disease, such as neurodegenerative disorders and certain forms of cancer, and aging. Antioxidants prevent the damage to macromolecules and cells by interfering with the free radicals. Several natural compounds that posses antioxidant activity have been reported from plant sources and are commercially promoted as nutraceuticals. Citrus fruits contain certain bioactive compounds such as phenolics, flavonoids, limonoids, carotenoids, and ascorbic acid. In this context, navel oranges were freeze-dried and extracted with five different solvents, such as hexane, ethyl acetate, acetone, methanol, and 8 methanol: 2 water. The extracts were dried under vacuum and screened for their radical scavenging activity using the 1,1-diphenyl-2-picrylhydrazyl method at 250, 500, and 1000 ppm. The methanol: water and methanol extracts of navel orange were found to be maximum (92.9%) and minimum (63.89%) radical scavenging activity at 1000 ppm. Furthermore, the antioxidant capacity of all extracts was assayed through the phosphomolybdenum method and expressed as equivalent to ascorbic acid (μmol/g of the extract). The order of antioxidant capacity for navel orange extracts was found to be ethyl acetate > acetone > methanol: water > methanol > hexane. It seems that the antioxidant capacity of the extracts is in accordance with the amount of phenolics/lycopene present in each fraction and may provide a good source of antioxidants. This project is based upon work supported by the USDA–CSREES under Agreement USDA IFAFS #2001-52102-02294 and USDA #2005-34402-14401 “Designing Foods for Health” through the Vegetable and Fruit Improvement Center.


2013 ◽  
Vol 781-784 ◽  
pp. 1020-1026
Author(s):  
Yu Ping Li ◽  
Li Hua Yao ◽  
Guang Jie Wu ◽  
Fu Quan Jiang ◽  
Xiang Yuan Xiong ◽  
...  

Xiao-Yan-Hua-Jie-San (XYHJS), a traditional Chinese prescription, is used as a medication recipe to clinically treat inflammation and hepatitis. In previous study, we reported the hepatoprotective effects of XYHJS by increasing an antioxidant enzyme activity in mice. In the present study, the main bioactive components of XYHJS and their antioxidant activity were further investigated by using different model systems in vitro. The total phenolics content in the extract of XYHJS was determined by the Folin-Ciocalteu method. Analysis of the major phenolic compounds in the extract of XYHYS was carried out by high-performance liquid chromatography (HPLC) and thin layer chromatographic (TLC) method. The total phenolic content of the extract was 2.84 ± 0.06 mg gallic acid equivalent (GAE)/g extract powder. The phenolic acid in XYHJS was found to be gallic acid (GA). The content of GA was 2.80 mg/ml by HPLC (n=5, RSD=1.26%). Furthermore, the antioxidant activity of XYHJS extract was determined by 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging activity and hydroxyl free radicals (·OH) scavenging activity assay. The radical scavenging activity of XYHJS increased significantly in a concentration-dependent manner. At a concentration of 2.5 mg/ml, the DPPH and ·OH scavenging activity was 89.94% and 91.53%, respectively. It can be concluded that the content of GA in XYHJS is very high and it is the main contributor to the antioxidant activity of XYHJS. Our study indicates that XYHJS prescription could be considered to be an effective agent in the prevention of various liver diseases associated with oxidative stress.


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