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Modifications of boronic ester pro-chelators triggered by hydrogen peroxide tune reactivity to inhibit metal-promoted oxidative stress.

Publication ,  Journal Article
Charkoudian, LK; Pham, DM; Kwon, AM; Vangeloff, AD; Franz, KJ
Published in: Dalton transactions (Cambridge, England : 2003)
November 2007

Several new analogs of salicylaldehyde isonicotinoyl hydrazone (SIH) and salicylaldehyde benzoyl hydrazone (SBH) that contain an aryl boronic ester (BSIH, BSBH) or acid (BASIH) in place of an aryl hydroxide have been synthesized and characterized as masked metal ion chelators. These pro-chelators show negligible interaction with iron(III), although the boronic acid versions exhibit some interaction with copper(II), zinc(II) and nickel(II). Hydrogen peroxide oxidizes the aryl boronate to phenol, thus converting the pro-chelators to tridentate ligands with high affinity metal binding properties. An X-ray crystal structure of a bis-ligated iron(III) complex, [Fe(SBH(m-OMe)(3))(2)]NO(3), confirms the meridonal binding mode of these ligands. Modifications of the aroyl ring of the chelators tune their iron affinity, whereas modifications on the boron-containing ring of the pro-chelators attenuate their reaction rates with hydrogen peroxide. Thus, the methoxy derivative pro-chelator (p-OMe)BASIH reacts with hydrogen peroxide nearly 5 times faster than the chloro derivative (m-Cl)BASIH. Both the rate of pro-chelator to chelator conversion as well as the metal binding affinity of the chelator influence the overall ability of these molecules to inhibit hydroxyl radical formation catalyzed by iron or copper in the presence of hydrogen peroxide and ascorbic acid. This pro-chelator strategy has the potential to improve the efficacy of medicinal chelators for inhibiting metal-promoted oxidative stress.

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Published In

Dalton transactions (Cambridge, England : 2003)

DOI

EISSN

1477-9234

ISSN

1477-9226

Publication Date

November 2007

Issue

43

Start / End Page

5031 / 5042

Related Subject Headings

  • Spectrum Analysis
  • Oxidative Stress
  • Models, Molecular
  • Metals
  • Kinetics
  • Inorganic & Nuclear Chemistry
  • Hydrogen Peroxide
  • Humans
  • Esters
  • Chelating Agents
 

Citation

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Charkoudian, L. K., Pham, D. M., Kwon, A. M., Vangeloff, A. D., & Franz, K. J. (2007). Modifications of boronic ester pro-chelators triggered by hydrogen peroxide tune reactivity to inhibit metal-promoted oxidative stress. Dalton Transactions (Cambridge, England : 2003), (43), 5031–5042. https://doi.org/10.1039/b705199a
Charkoudian, Louise K., David M. Pham, Ashley M. Kwon, Abbey D. Vangeloff, and Katherine J. Franz. “Modifications of boronic ester pro-chelators triggered by hydrogen peroxide tune reactivity to inhibit metal-promoted oxidative stress.Dalton Transactions (Cambridge, England : 2003), no. 43 (November 2007): 5031–42. https://doi.org/10.1039/b705199a.
Charkoudian LK, Pham DM, Kwon AM, Vangeloff AD, Franz KJ. Modifications of boronic ester pro-chelators triggered by hydrogen peroxide tune reactivity to inhibit metal-promoted oxidative stress. Dalton transactions (Cambridge, England : 2003). 2007 Nov;(43):5031–42.
Charkoudian, Louise K., et al. “Modifications of boronic ester pro-chelators triggered by hydrogen peroxide tune reactivity to inhibit metal-promoted oxidative stress.Dalton Transactions (Cambridge, England : 2003), no. 43, Nov. 2007, pp. 5031–42. Epmc, doi:10.1039/b705199a.
Charkoudian LK, Pham DM, Kwon AM, Vangeloff AD, Franz KJ. Modifications of boronic ester pro-chelators triggered by hydrogen peroxide tune reactivity to inhibit metal-promoted oxidative stress. Dalton transactions (Cambridge, England : 2003). 2007 Nov;(43):5031–5042.
Journal cover image

Published In

Dalton transactions (Cambridge, England : 2003)

DOI

EISSN

1477-9234

ISSN

1477-9226

Publication Date

November 2007

Issue

43

Start / End Page

5031 / 5042

Related Subject Headings

  • Spectrum Analysis
  • Oxidative Stress
  • Models, Molecular
  • Metals
  • Kinetics
  • Inorganic & Nuclear Chemistry
  • Hydrogen Peroxide
  • Humans
  • Esters
  • Chelating Agents