Linked Life Data

9808293

Source:http://linkedlifedata.com/resource/pubmed/id/9808293

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1999-2-1
pubmed:abstractText
The molecular motions of D-alpha-galacturonic acid monohydrate (GA) and its derivative methyl-alpha-D-galacturonic acid methyl ester monohydrate (MGAM) in the solid state have been studied using 1H NMR. Both protonated and deuterium exchanged samples have been used. Spin-lattice relaxation times in the laboratory and rotating frames as well as second moments have been measured over the temperature range 90-370 K. Analysis of results has shown that in GA spin-lattice relaxation is chiefly by hydroxyl groups and water of crystallization. In MGAM, methyl groups dominate spin-lattice relaxation in the laboratory frame at the low temperature. Hydroxyl groups and water of crystallization contribute to the spin-lattice relaxation in the laboratory frame in the high temperature region. In the rotating frame motion of hydroxyl groups and water of crystallization provide the main relaxation pathway. Changes in the static second moment with temperature can be reasonably well predicted using values of correlation time and motionally averaged second moments obtained by fitting the spin-lattice relaxation data. 13C CPMAS spectra for GA and MGAM are also described.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0926-2040
pubmed:author
pubmed:issnType
Print
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
21-30
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Molecular motions of D-alpha-galacturonic acid (GA) and methyl-D-alpha-galacturonic acid methyl ester (MGAM) in the solid state-A proton NMR study.
pubmed:affiliation
Institute of Food Research, Norwich Research Park, Colney, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't