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Catalytic radical reduction in aqueous solution via oxidation of biologically-relevant alcohols
Metalloenzymes that normally perform catalytic antioxidant or radical-degrading functions, as well as small-molecule complexes that mimic them, can also exert pro-oxidant or radical-forming effects depending on the identity of the terminal reductant. Because nitroxyl radicals function as redox activ...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Royal Society of Chemistry
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6013915/ https://www.ncbi.nlm.nih.gov/pubmed/30155048 http://dx.doi.org/10.1039/c6sc00651e |
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author | Htet, Yamin Tennyson, Andrew G. |
author_facet | Htet, Yamin Tennyson, Andrew G. |
author_sort | Htet, Yamin |
collection | PubMed |
description | Metalloenzymes that normally perform catalytic antioxidant or radical-degrading functions, as well as small-molecule complexes that mimic them, can also exert pro-oxidant or radical-forming effects depending on the identity of the terminal reductant. Because nitroxyl radicals function as redox active cocatalysts in the aerobic oxidation of alcohols, we hypothesized that catalytic radical reduction could be achieved via the oxidation of biologically-relevant alcohols. Herein we report an organoruthenium complex (Ru1) that catalyzed reduction of 2,2′-azino-bis(3-ethylbenzo-thiazoline-6-sulfonate) radical monoanion (ABTS˙(–)) to ABTS(2–) in phosphate buffered saline (pH 7.4) using MeOH, EtOH, i-PrOH, serine, threonine, glucose, arabinose, methyl lactate or dimethyl malate as the terminal reductant. Replacing either the C–H or O–H groups of a –CHOH– moiety resulted in the loss of ABTS˙(–) reducing ability. Moreover, in conjunction with an alcohol terminal reductant, Ru1 was able to inhibit the oxidation of ABTS(2–) by H(2)O(2) and horseradish peroxidase, even after multiple successive challenges with excess H(2)O(2) or ABTS˙(–). Collectively, these results demonstrate that Ru1 inhibits the oxidative formation of and catalyzes the reduction of radicals in aqueous solution via oxidation of biologically-relevant alcohols. |
format | Online Article Text |
id | pubmed-6013915 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Royal Society of Chemistry |
record_format | MEDLINE/PubMed |
spelling | pubmed-60139152018-08-28 Catalytic radical reduction in aqueous solution via oxidation of biologically-relevant alcohols Htet, Yamin Tennyson, Andrew G. Chem Sci Chemistry Metalloenzymes that normally perform catalytic antioxidant or radical-degrading functions, as well as small-molecule complexes that mimic them, can also exert pro-oxidant or radical-forming effects depending on the identity of the terminal reductant. Because nitroxyl radicals function as redox active cocatalysts in the aerobic oxidation of alcohols, we hypothesized that catalytic radical reduction could be achieved via the oxidation of biologically-relevant alcohols. Herein we report an organoruthenium complex (Ru1) that catalyzed reduction of 2,2′-azino-bis(3-ethylbenzo-thiazoline-6-sulfonate) radical monoanion (ABTS˙(–)) to ABTS(2–) in phosphate buffered saline (pH 7.4) using MeOH, EtOH, i-PrOH, serine, threonine, glucose, arabinose, methyl lactate or dimethyl malate as the terminal reductant. Replacing either the C–H or O–H groups of a –CHOH– moiety resulted in the loss of ABTS˙(–) reducing ability. Moreover, in conjunction with an alcohol terminal reductant, Ru1 was able to inhibit the oxidation of ABTS(2–) by H(2)O(2) and horseradish peroxidase, even after multiple successive challenges with excess H(2)O(2) or ABTS˙(–). Collectively, these results demonstrate that Ru1 inhibits the oxidative formation of and catalyzes the reduction of radicals in aqueous solution via oxidation of biologically-relevant alcohols. Royal Society of Chemistry 2016-07-01 2016-03-10 /pmc/articles/PMC6013915/ /pubmed/30155048 http://dx.doi.org/10.1039/c6sc00651e Text en This journal is © The Royal Society of Chemistry 2016 https://creativecommons.org/licenses/by-nc/3.0/This article is freely available. This article is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported Licence (CC BY-NC 3.0) |
spellingShingle | Chemistry Htet, Yamin Tennyson, Andrew G. Catalytic radical reduction in aqueous solution via oxidation of biologically-relevant alcohols |
title | Catalytic radical reduction in aqueous solution via oxidation of biologically-relevant alcohols
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title_full | Catalytic radical reduction in aqueous solution via oxidation of biologically-relevant alcohols
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title_fullStr | Catalytic radical reduction in aqueous solution via oxidation of biologically-relevant alcohols
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title_full_unstemmed | Catalytic radical reduction in aqueous solution via oxidation of biologically-relevant alcohols
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title_short | Catalytic radical reduction in aqueous solution via oxidation of biologically-relevant alcohols
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title_sort | catalytic radical reduction in aqueous solution via oxidation of biologically-relevant alcohols |
topic | Chemistry |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6013915/ https://www.ncbi.nlm.nih.gov/pubmed/30155048 http://dx.doi.org/10.1039/c6sc00651e |
work_keys_str_mv | AT htetyamin catalyticradicalreductioninaqueoussolutionviaoxidationofbiologicallyrelevantalcohols AT tennysonandrewg catalyticradicalreductioninaqueoussolutionviaoxidationofbiologicallyrelevantalcohols |