Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
43
pubmed:dateCreated
2007-11-9
pubmed:abstractText
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.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1477-9226
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5031-42
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Modifications of boronic ester pro-chelators triggered by hydrogen peroxide tune reactivity to inhibit metal-promoted oxidative stress.
pubmed:affiliation
Department of Chemistry, Duke University, Durham, NC 27708-0346, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't