Linked Life Data

21561126

Source:http://linkedlifedata.com/resource/pubmed/id/21561126

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2011-5-26
pubmed:abstractText
The kinetics of ligand exchange between ferric citrate and desferrioxamine B (DFB) was investigated at pH 8.0 and high citrate/Fe molar ratios (500-5000) with particular attention given to understanding the precise mechanism of ligand exchange. Ferric citrate complexes present in a test solution and therefore involved in the reaction with the incoming ligand (DFB) were initially examined by evaluating ferric citrate speciation on the basis of published thermodynamic constants. The speciation analysis indicated that mononuclear (mono- and dicitrate) ferric complexes are the major species responsible for the ligand exchange with DFB under the conditions examined in the present work. Given the tendency of DFB to adjunctively associate with the ferric citrate complexes, we propose a kinetic model containing the following three mechanisms: (i) direct association of DFB to the ferric dicitrate complex prior to any dissociation of citrate molecules from the Fe center, (ii) adjunctive association of DFB toward ferric monocitrate complex following dissociation of one molecule of citrate from the parent complex, and (iii) complexation of hydrated Fe by DFB after sequential dissociation of two molecules of citrate from the Fe center. Overall rates for the ligand exchange were determined by spectrophotometrically monitoring the formation of ferrioxamine B. Further analysis in quantifying the rate of each mechanism by use of published and determined rate constants of relevant elemental reactions suggested that the first and second mechanisms were significant under our experimental conditions where [Cit] ? [DFB] with the relative importance of these two pathways depending on citrate concentration.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1520-5215
pubmed:author
pubmed:copyrightInfo
© 2011 American Chemical Society
pubmed:issnType
Electronic
pubmed:day
2
pubmed:volume
115
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5371-9
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Mechanism and kinetics of ligand exchange between ferric citrate and desferrioxamine B.
pubmed:affiliation
Department of Civil and Environmental Engineering, Tohoku University, Aoba 6-6-06 Aobaku, Sendai 980-8579, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't