March 26, 2003 - Organisms have an efficient defense system to protect themselves against the oxidative stress induced by ROS [9]. Recent investigations have shown that antioxidant efficiency correlates with the oxidative defense system and different human diseases including cancer, athersclerosis, and the aging processes may be relate to oxidative damage [10]. Antioxidants interfere with the oxidation process by reacting with free radicals, chelating free catalytic metals and also by acting as scavengers of oxygen by-products.

August 1, 2020 - In summary, we reported on the very first Fe(iii) peptide chelators exhibiting antioxidant properties thanks to a dual indirect (i.e., inhibition of the metal redox activity) and direct (i.e., HO˙ radical scavenging via phenylalanine hydroxylation) mode of action. In particular, we highlighted that the FD3K pentapeptide strongly inhibits both the iron redox activity (up to −89%) and the ROS production (−86% and −95% for H2O2 and HO˙, respectively) at physiological pH, rivalling with deferoxamine (DFO), a clinically used iron chelator and antioxidant standard.59,60,62 Contrasting with the fastidious and hazardous methods commonly used,14–16,18 this work demonstrates the relevance and the efficiency of a more rational approach to discover new antioxidant peptides.

January 10, 2022 - In addition, natural metal chelating compounds including phenolics and flavonoids are desired over synthetic chelating agents, which are associated with the problem of toxicity [87]. Antioxidants block the harmful effects of ROS and are divided into two main groups, natural and synthetic, prevent free radicals from harming the body by catching and neutralizing them [88,89,90]. Antioxidants are described as substances that effectively scavenge ...

June 2, 2020 - To limit ROS production and their detrimental effects, we report on the synthesis, physicochemical studies and antioxidant assays of an innovative series of synthetic pentapeptides exhibiting a dual direct/indirect mode of action, both as iron(III)-chelators and as radical scavengers. These combined effects lead to a drastic reduction of in vitro reactive oxygen species production up to 95% for the more reactive hydroxyl radical. Metal ions ...

In first place metal chelation itself, in the obvious sense of free metal ion withdrawal from the oxidizable medium, prevents the initiation of a free radical-mediated oxidation processes through mechanisms of Fenton or lipid peroxidation. In addition, the incorporation of Cu adds to [Chr2Cu] the ability of a free radical scavenger, already described for similar Cu-chelate compounds. This collection of beneficial properties positions the complex as a remarkably promising bioprotector towards ROS-mediated oxidation.

May 28, 2009 - Vitamin C scavenges the aqueous ... (EDTA).60,61 · Metal chelation studies have shown that chelation of Zn(II) and Mn(II) ions takes place via two—OH groups while, Cd(II)...

Fe2+ can simplify the production of ROS in living systems. The metal chelating ability

March 1, 2011 - In plants, MTs are suggested to ... of their cysteine residues. Recent reports show that MTs are also involved in the scavenging of reactive oxygen species (ROS)....

The present results revealed that the scavenging activities of, at least, superoxide radical and hydroxyl radical were enhanced by the chelation with divalent metal ions.

January 17, 2023 - These effects promote a considerable change in the electronic charge distribution of the ligand that facilitates the electron–proton loss and thus increases the radical scavenging ability of the resulting complex. Even while metal ions such as Mn, Fe, Cu, Co, and Zn are complex in many biological structures and play a crucial role in the functioning of organisms, it is important for reducing toxicity in the design of novel chelates antioxidants.

September 14, 2009 - Abstract • Introduction • Free radical scavenging - Scavenging superoxide and other ROS - Scavenging hydroxyl radical and other ROS - Stable radical scavenging • Metal ion (Fe2+, Fe3+, Cu2+ a...

November 30, 2023 - In addition to the catechol groups, ... a mechanism involving the transfer of H-atoms [165]. Moreover, the scavenging of ROS by PDA may also be associated with its strong ability to chelate metal ions and its SOD-like activity, which are related ...

August 20, 2023 - ROS scavenging and heavy metal detoxification.

Phenolics act as metal ion chelators and free radical scavengers to reduce dangerous ROS, which lead to various human diseases. These activities take place by donating electrons, and this fact allows some optical and electrochemical techniques to be used in the determination of total phenolic ...

February 5, 2017 - In plants, MTs are suggested to ... of their cysteine residues. Recent reports show that MTs are also involved in the scavenging of reactive oxygen species (ROS)....

Eventually theoretical calculations suggest that the proton-transfer-associated superoxide-scavenging activity is enhanced after binding metal ions, and that Ga(3+) complexes display possible superoxide dismutase (SOD)-like activity. Copyright © 2014 Elsevier Inc.

Mechanism of superoxide anion radical scavenging activity of quercetin 5. ... Mechanism of DNA damage induced by quercetin copper complex. This journal is © The Royal Society of Chemistry 2015 ... Open Access Article. Published on 12 March 2015. Downloaded on 10/15/2025 1:21:39 PM. ... Creative Commons Attribution 3.0 Unported Licence. ... Metal ion (Cu2+) chelating activity of anthocynidine (cynidin 19).

January 1, 2012 - The highest TPC, TFC, and antioxidant activity (metal chelation, FRAP, DPPH, and ABTS) were shown for HRM samples, followed by HRE samples, while the lowest were found for pure solvents. Incorporating H2 into all solvents significantly increased TPC, TFC, metal chelation, DPPH, and ABTS scavenging activity, as well as b*, C*, H°, chlorophyll, lycopene, and β-carotene values.

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February 17, 2015 - Previous studies revealed that, active metal ions such as Fe2+ interact with H2O2 through Fenton chemistry to form hydroxyl radicals (OH), which is the most ROS known, being able to initiate free radical chain reactions by abstracting hydrogen ...