scholarly journals Biocompatible Platinum Nanoclusters Prepared Using Bitter Gourd Polysaccharide for Colorimetric Detection of Ascorbic Acid

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 647
Author(s):  
Kai Liu ◽  
Yu Zhao ◽  
Lu Zhang ◽  
Mengmeng He ◽  
Weifeng Lin ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Human Body ◽  
High Selectivity ◽  
Colorimetric Detection ◽  
Antioxidant Properties ◽  
Bitter Gourd ◽  
Oh Radicals ◽  
High Cell ◽  
Good Biocompatibility ◽  
Platinum Nanoclusters

Ascorbic acid is an organic compound with antioxidant properties that can protect the human body from the threat of free radicals. Therefore, it is important to detect the existence and measure the concentration of ascorbic acid to regulate its content in the human body. In this work, we prepared bitter gourd polysaccharide (BGP)-stabilized platinum nanoclusters (Pt-BGP NCs) by reacting BGP with K2PtCl4. Pt-BGP NCs and catalyzed the decomposition of H2O2 to generate •OH radicals, which could oxidize TMB to form oxidized TMB (oxTMB), indicating their peroxidase-like properties. The kinetics followed the Michaelis–Menten equation. Furthermore, the colorimetric detection of ascorbic acid using Pt-BGP NCs showed high selectivity and a low detection limit of 0.191 μM. The accuracy of real sample detection using Pt-BGP NCs was as high as 98.9%. More importantly, Pt-BGP NCs had high cell biocompatibility and extremely low hemolysis rate due to the component of BGP. In summary, the prepared Pt-BGP NCs with reductive activity and good biocompatibility have good application prospects in colorimetric detection of ascorbic acid.

Green synthesis of platinum nanoclusters using lentinan for sensitively colorimetric detection of glucose

2021 ◽  
Vol 172 ◽  
pp. 289-298
Author(s):  
Le Dong ◽  
Ruyu Li ◽  
Liqiu Wang ◽  
Xifa Lan ◽  
Haotian Sun ◽  
...  
Keyword(s):  
Green Synthesis ◽  
Colorimetric Detection ◽  
Platinum Nanoclusters

scholarly journals Complexes of Copper and Iron with Pyridoxamine, Ascorbic Acid, and a Model Amadori Compound: Exploring Pyridoxamine’s Secondary Antioxidant Activity

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 208
Author(s):  
Guillermo García-Díez ◽  
Roger Monreal-Corona ◽  
Nelaine Mora-Diez
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Rate Constant ◽  
Stable Complex ◽  
Aqueous Environment ◽  
Oh Radicals ◽  
Bidentate Ligands ◽  
Superoxide Radical Anion ◽  
Amadori Compound ◽  
The Stability

The thermodynamic stability of 11 complexes of Cu(II) and 26 complexes of Fe(III) is studied, comprising the ligands pyridoxamine (PM), ascorbic acid (ASC), and a model Amadori compound (AMD). In addition, the secondary antioxidant activity of PM is analyzed when chelating both Cu(II) and Fe(III), relative to the rate constant of the first step of the Haber-Weiss cycle, in the presence of the superoxide radical anion (O2•−) or ascorbate (ASC−). Calculations are performed at the M05(SMD)/6-311+G(d,p) level of theory. The aqueous environment is modeled by making use of the SMD solvation method in all calculations. This level of theory accurately reproduces the experimental data available. When put in perspective with the stability of various complexes of aminoguanidine (AG) (which we have previously studied), the following stability trends can be found for the Cu(II) and Fe(III) complexes, respectively: ASC < AG < AMD < PM and AG < ASC < AMD < PM. The most stable complex of Cu(II) with PM (with two bidentate ligands) presents a ΔGf0 value of −35.8 kcal/mol, whereas the Fe(III) complex with the highest stability (with three bidentate ligands) possesses a ΔGf0 of −58.9 kcal/mol. These complexes can significantly reduce the rate constant of the first step of the Haber-Weiss cycle with both O2•− and ASC−. In the case of the copper-containing reaction, the rates are reduced up to 9.70 × 103 and 4.09 × 1013 times, respectively. With iron, the rates become 1.78 × 103 and 4.45 × 1015 times smaller, respectively. Thus, PM presents significant secondary antioxidant activity since it is able to inhibit the production of ·OH radicals. This work concludes a series of studies on secondary antioxidant activity and allows potentially new glycation inhibitors to be investigated and compared relative to both PM and AG.

scholarly journals Exogenous Antioxidants Impact on UV-Induced Changes in Membrane Phospholipids and the Effectiveness of the Endocannabinoid System in Human Skin Cells

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1260
Author(s):  
Agnieszka Gęgotek ◽  
Anna Jastrząb ◽  
Marta Dobrzyńska ◽  
Michał Biernacki ◽  
Elżbieta Skrzydlewska
Keyword(s):  
Ascorbic Acid ◽  
Cell Viability ◽  
Human Skin ◽  
Phospholipid Fatty Acid ◽  
Antioxidant Properties ◽  
Endocannabinoid System ◽  
Membrane Phospholipids ◽  
Skin Cells ◽  
Human Skin Cells ◽  
Induced Changes

Natural antioxidants effectively counteract changes caused by UV radiation in human skin cells. However, their action is limited due to their lipo/hydrophilicity. Therefore, the aim of this study was to analyze the mutual protective action of hydrophilic ascorbic acid and partially lipophilic rutin against UVA/UVB-induced changes in membranes phospholipid and endocannabinoid system in keratinocytes and fibroblasts. Obtained results clearly showed that, despite the stronger antioxidant properties of ascorbic acid, the lipid membranes were more effectively protected against UV-induced oxidation by rutin, including changes in phospholipid fatty acid levels, prevention against reactive aldehydes formation and endocannabinoids degradation. Ascorbic acid more strongly prevented UV-induced endocannabinoid receptors expression in fibroblasts, especially CB1. However, the combined action of used antioxidants resulted in the greatest cytoprotective effect, which was evident in the inflammatory marker TNFα down-regulation and increased cell viability following cell irradiation. The applied mixture of antioxidants showed a stronger protective in relation to membrane phospholipids in keratinocytes and in the endocannabinoid system in fibroblasts. In conclusion, it can be suggested that combined antioxidant capacities of ascorbic acid and rutin protects against lipid peroxidation but also decreases the UV-induced inflammation by direct interaction with the endocannabinoid system, thus increasing skin cell viability.

VARIETAL FEATURES OF TUBERS OF JERUSALEM ARTICHOKE, GROWING IN THE KRASNODAR REGION AND THE Adygea Republic

2019 ◽  
Author(s):  
Н.Т. Шамкова ◽  
В.Ю. Токарев ◽  
А.В. Добровольская ◽  
А.З. Тодорова ◽  
А.И. ВЕРЕЩАГИНА
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Orotic Acid ◽  
Antioxidant Properties ◽  
Jerusalem Artichoke ◽  
Biotechnological Potential ◽  
Total Sugars ◽  
Krasnodar Region ◽  
Public Catering ◽  
Pectin Substances

Определен биотехнологический потенциал топинамбура сортов Новость ВИР, Скороспелка, Интерес, произрастающего в Краснодарском крае и Республике Адыгея, урожаев 2011 2018 гг. Установлено, что клубни топинамбура сорта Интерес превосходят сорта Новость ВИР и Скороспелка по содержанию, : общих сахаров на 22,41 и 14,34 инулина 41,82 и 32,99 пектиновых веществ 22,39 и 49,75 аскорбиновой кислоты 35,27 и 39,29 хлорогеновой кислоты 3,66 и 18,29 оротовой кислоты 88,89 и 84,89 соответственно. Сорт Интерес в сравнении с сортами Новость ВИР и Скороспелка содержит на 245,24 и 243,33 меньше никотиновой кислоты и на 100,0 и 108,33 кофейной кислоты соответственно. Содержание гистидина в клубнях топинамбура сортов Интерес, Новость ВИР и Скороспелка составляет 132,36 44,83 и 88,21 мг/кг аргинина 2017,2 958,56 и 460,44 мг/кг соответственно. В комплексе с аскорбиновой кислотой органические кислоты клубней топинамбура обладают выраженными антиоксидантными свойствами. Установлено, что в результате бланширования антиоксидантная активность топинамбура сорта Интерес возросла на 15,6. Таким образом, сорт Интерес наиболее перспективен для переработки в условиях предприятий общественного питания. The biotechnological potential of Jerusalem artichoke varieties Novost VIR, Skorospelka, Interes growing in the Krasnodar region and the Adygea Republic, harvest 2011 2018 has been determined. It was found that Jerusalem artichoke tubers of the Interes variety are superior to Novost VIR and Skorospelka varieties in content, : total sugars by 22,41 and 14,34 inulin 41,82 and 32,99 pectin substances 22,39 and 49,75 ascorbic acid 35,27 and 39,29 chlorogenic acid 3,66 and 18,29 orotic acid 88,89 and 84,89, respectively. Variety Interes in comparison with Novost VIR and Skorospelka varieties contains 245,24 and 243,33 less nicotinic acid and 100,00 and 108,33 coffee acid, respectively. The content of histidine in the tubers of Jerusalem artichoke varieties of Interes, Novost VIR, Skorospelka is 132,36 44,83 and 88,21 mg/kg arginine 2017,2 958,56 and 460,44 mg/kg, respectively. In a complex with ascorbic acid, organic acids of Jerusalem artichoke tubers have pronounced antioxidant properties. It was found that as a result of blanching, the antioxidant activity of Jerusalem artichoke of the Interes variety increases by 15,6. Thus, the Interes variety is most promising for processing in public catering facilities.

scholarly journals Qualities of Native Apple Cultivar Juices Characteristic of Central Europe

2012 ◽  
Vol 40 (1) ◽  
pp. 222 ◽  
Author(s):  
Otakar ROP ◽  
Martin POSOLDA ◽  
Jiri MLCEK ◽  
Vojtech REZNICEK ◽  
Jiri SOCHOR ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Ascorbic Acid ◽  
Hydroxyl Radical ◽  
Antioxidant Capacity ◽  
Antioxidant Properties ◽  
Landscape Management ◽  
Ascorbic Acid Content ◽  
Fruit Trees ◽  
Apple Fruit ◽  
Scavenging Effect

During the last century due to the changes in landscape management, in country people’s lives and with intensive fruit-growing the native cultivars of apple fruit trees have been gradually disappearing. The aim of the study was to compare the juices made of native apple cider cultivars. The cultivars-‘Boikovo’, ‘Jadernicka moravska’, ‘Kardinal zihany’, ‘Panenske ceske’, ‘Parmena zlata zimni’, ‘Strymka’ growing in the locality of the Litencicke Hills in the eastern part of the Czech Republic were selected. For comparison, the fruits of commercial ‘Idared’ cultivar were also included. The chemical composition, antioxidant capacity, phenols, flavonoids and ascorbic acid content and the influence of juices on scavenging activity of nitric oxide and hydroxyl radical were measured. The mutual ratio of examined properties which were found, provide information about qualities and possibilities of use of native cultivars. High antioxidant properties characterize the juice of native apple cultivars. In particular, the ‘Strymka’ cultivar contained 2,637.34 mg of AAE (ascorbic acid equivalent) per litre in case of antioxidant capacity. In the juice of this cultivar the value of 144.05 mg of ascorbic acid per litre was recorded. As regards the ‘Panenske ceske’ cultivar, antioxidant capacity was 2,548.38 mg of AAE l-1 and in relation to ascorbic acid, the value was 145.35 mg l-1. Similarly, high values were observed in both cultivars concerning the scavenging effect of apple juices on hydroxyl radical and nitric oxide (the ‘Strymka’ cultivar 16.38% and 19.26%, the ‘Panenske ceske’ cultivar 16.31% and 18.60%).

scholarly journals Evaluation of Antioxidant Properties ofPhaulopsis fascisepalaC.B.Cl. (Acanthaceae)

2009 ◽  
Vol 6 (2) ◽  
pp. 227-231 ◽  
Author(s):  
S. A. Adesegun ◽  
A. Fajana ◽  
C. I. Orabueze ◽  
H. A. B. Coker
Keyword(s):  
Ascorbic Acid ◽  
Leaf Extract ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Total Phenolic ◽  
Chelating Ability

The antioxidant activities of crude extract ofPhaulopsis fascisepalaleaf were evaluated and compared with α-tocopherol and BHT as synthetic antioxidants and ascorbic acid as natural-based antioxidant.In vitro, we studied its antioxidative activities, radical-scavenging effects, Fe2+-chelating ability and reducing power. The total phenolic content was determined and expressed in gallic acid equivalent. The extract showed variable activities in all of thesein vitrotests. The antioxidant effect ofP. fascisepalawas strongly dose dependent, increased with increasing leaf extract dose and then leveled off with further increase in extract dose. Compared to other antioxidants used in the study, α-Tocopherol, ascorbic acid and BHT,P. fascisepalaleaf extract showed less scavenging effect on α,α,-diphenyl-β-picrylhydrazyl (DPPH) radical and less reducing power on Fe3+/ferricyanide complex but better Fe2+-chelating ability. These results revealed thein vitroantioxidant activity ofP.fascisepala.Further investigations are necessary to verify these activitiesin vivo.

Estrogen diminishes postischemic hydroxyl radical production

1998 ◽  
Vol 274 (6) ◽  
pp. H1950-H1954 ◽  
Author(s):  
Nansie A. McHugh ◽  
Gary F. Merrill ◽  
Saul R. Powell
Keyword(s):  
Tissue Injury ◽  
Antioxidant Properties ◽  
Cardioprotective Effect ◽  
Oh Radicals ◽  
Acute Administration ◽  
Reperfusion Arrhythmias ◽  
Conjugated Equine Estrogen ◽  
Anesthetized Dogs ◽  
Reperfusion Of The Myocardium ◽  
Equine Estrogens

Reperfusion of blood flow to an ischemic myocardium is imperative to survival; ironically, it may also manifest several pathophysiological conditions. The most important of these are reperfusion arrhythmias and tissue injury and/or death. The mechanisms involved in reperfusion arrhythmias remain to be fully elucidated; however, increasing evidence indicates that reperfusion-induced arrhythmias are a free radical-mediated phenomenon. Acute administration of conjugated equine estrogen to dogs attenuates ischemia- and reperfusion-induced arrhythmias. The cardioprotective effect of estrogens in postmenopausal women is well documented, and recent studies suggest that estrogens possess strong antioxidant properties, with equine estrogens most potent. In this study we show that administration of conjugated equine estrogen to fully anesthetized dogs abolishes the burst of ⋅ OH radicals typically produced on reperfusion of the myocardium. This indicates that estrogen might attenuate reperfusion-induced ventricular arrhythmias by virtue of its antioxidant properties, suggesting a novel cardioprotective effect of the hormone.

scholarly journals A study on Antioxidant Properties of Different Extracts from Kitaibelia balansae

Proceedings ◽  
2019 ◽  
Vol 40 (1) ◽  
pp. 23
Author(s):  
Zengin ◽  
Aygun ◽  
Aktumsek
Keyword(s):  
Ethyl Acetate ◽  
Human Body ◽  
Antioxidant Properties ◽  
Water Extract ◽  
Antioxidant Ability ◽  
Chemical Methods ◽  
Potential Source ◽  
First Time ◽  
Antioxidant Effects ◽  
Ethyl Acetate Extracts

Nowadays, knowledge of ancient botanical medicinal practices and application of modern phytochemical techniques have provided the excellent tools for the purification and structural elucidation of various phyto-compounds, which, in turn, has given insights into their mode of action on the human body. This study has been designed to investigate for the first time the antioxidant effects of the ethyl acetate, methanolic, and water extracts of Kitaibelia balansae. Different chemical methods were performed and the observed abilities depend on the solvent used. The best antioxidant ability was noted in water extract, followed by methanol and ethyl acetate extracts. The highest level of phenolic was also detected in water extract. The present findings suggest that K. balansae can be considered as a potential source of bioactive compounds for novel phytopharmaceuticals development

scholarly journals Antioxidant activity test of ethyl acetate fraction of binjai (Mangifera Caesia) leaf ethanol extract

2018 ◽  
Vol 51 (4) ◽  
pp. 164
Author(s):  
K. Khairiah ◽  
Irham Taufiqurrahman ◽  
Deby Kania Tri Putri
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Ethyl Acetate ◽  
Secondary Metabolite ◽  
Antioxidant Properties ◽  
Linear Connection ◽  
Sampling Technique ◽  
Ethanol Extract ◽  
Ethyl Acetate Fraction ◽  
Control Group

Background: Binjai (Mangifera caesia) is a herb derived from South Kalimantan possessing antioxidant properties which promote wound healing inhibiting oxidation radicals. The natural antioxidants present in binjai leaves can be extracted by fractionation. Purpose: This study aimed to analyze the antioxidant activity of ethyl acetate fraction in 96% ethanol extract of binjai leaf. Methods: The study constituted a pure experimental study incorporating a post-test design with only random sampling technique consisting of two groups, namely; an ethyl acetate fraction as the treatment group and ascorbic acid as the positive control group. The leaves were treated in accordance with the soxhlet method and subsequently fractionated to extract ethyl acetate fraction. This was used to measure antioxidant activity with DPPH radical damping method using a UV-Vis spectrophotometer. A linear regression calculation was performed with a standard curve to quantify the IC50 value, before the ethyl acetate fraction underwent a qualitative test of secondary metabolite. Results: An independent t-test indicated significant differences between groups, an average value of IC50 in ascorbic acid of 13.812 ppm with 0.996 linearity and a fraction of ethyl acetate 38.526 ppm with a linearity of 0.999. In contrast, at this linearity value ascorbic acid and ethyl fraction acetate demonstrate a very high linear connection between concentration and inhibition. A secondary metabolite test conducted on the ethyl acetate fraction produced positive results for flavonoid, tannins, and phenol. Conclusion: Based on the IC50 parameters, the fraction of ethyl acetate in 96% ethanol extract of binjai leaf produces very strong antioxidant activity in the content of the compounds in the fraction, namely: flavonoid, tannins and phenol.

scholarly journals Antioxidant Activities of Extracts from Celery Leaves (Apium Graveolens L) Grown in Jos, Nigeria

2020 ◽  
pp. 1-5
Author(s):  
M. Suleman Stephen ◽  
E. A. Adelakun ◽  
J. H. Kanus ◽  
Meshack M. Gideon
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Ethanolic Extract ◽  
Acetone Extract ◽  
Apium Graveolens ◽  
Isolation And Identification ◽  
Celery Plant

The presence of natural antioxidant in plants is well known. Plant phenolics constitute one of the major groups of components that act as antioxidant and free radical terminator. Hence, this study focused on investigating the antioxidant activity of Celery plant (Apium graveolens L). The fresh leaves were collected, crushed and extracted with ethanol and acetone by maceration. The radical scavenging properties of the extracts were determined by measuring changes in absorbance of DPPH radical at a wave lenght of 517 nm by UV and ascorbic acid is used as the standard. It showed that the crude ethanolic extract has higher antioxidant activity compared to ascorbic acid and acetone extract with less scavenging activity. The values were (IC50 114.6 µg/mL) for ascorbic acid, (IC50 112 µg/mL) for the crude ethanolic extract and (IC50172 µg/mL) for crude acetone extract. The result shows that Celery plant grown in Jos possess good antioxidant properties which may be linked to the presence of phenolics and flavonoids in the plant, which justifies its use as a medicinal plant. This can be further investigated for the isolation and identification of active compounds of medicinal utilities.

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