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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
2
|
| pubmed:dateCreated |
1992-9-3
|
| pubmed:abstractText |
The acid dissociation constants for N-(2-mercaptoethyl)-1,3-diaminopropane (WR-1065) were determined in D2O by 360- and 500-MHz NMR spectroscopy. Results obtained at 0.21 M initial ionic strength and 26 degrees C were corrected to 25 degrees C yielding pKD1 = 8.28 +/- 0.04, pKD2 = 9.88 +/- 0.07, and pKD3 = 11.58 +/- 0.03. Correction of these values for the effect of the deuterium isotope upon the ionization reaction yielded dissociation constants in water of pKH1 = 7.69 +/- 0.09, pKH2 = 9.35 +/- 0.09, and pKH3 = 11.10 +/- 0.08. Analysis of the changes in chemical shift with pD indicated that the first ionization occurs largely through ionization of the thiol group (approximately 67%) and to a lesser extent the secondary ammonium group (approximately 30%), whereas the third ionization involves mainly the secondary ammonium group (approximately 65%) and to a lesser extent the primary ammonium group (approximately 30%). Estimates of the microscopic pK values for WR-1065 were also obtained from the results.
|
| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Aug
|
| pubmed:issn |
0033-7587
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
131
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
143-51
|
| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading | |
| pubmed:year |
1992
|
| pubmed:articleTitle |
Determination of the acid dissociation constants for WR-1065 by proton NMR spectroscopy.
|
| pubmed:affiliation |
Department of Chemistry, University of California, San Diego, La Jolla 92093.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
|