Linked Life Data

12967116

Source:http://linkedlifedata.com/resource/pubmed/id/12967116

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
2003-9-11
pubmed:abstractText
The Boreal forest fulvic acid known as Laurentian fulvic acid (LFA) has been interrogated by state of the art heteronuclear and 2D high resolution NMR techniques. It is shown that one can obtain very highly resolved and informative spectra of a traditionally fractionated material. It was possible to observe a proton coupled system of up to seven bonds in the TOCSY spectrum and 329 peaks in the 1H,13C-HSQC spectrum. It is found that the majority of the nitrogen in this sample is in the form of ammonium cations. From the combination of inverse-gated decoupling, APT, and INEPT 13C spectra of LFA it can be concluded that while the aromatic moieties of LFA are highly unfunctionalized, the carbohydrate moieties are highly functionalized. Proton coupled networks are observed in the TOCSY spectrum between and within the aliphatic, functionalized aliphatic, and heteroatom substituted regions and, to a lesser extent, also between the amine/aromatic and heteroatom substituted regions. The HMBC spectrum confirms that both the aliphatic and heteroatom moieties are highly functionalized with carboxylic and alcoholic functional groups, while the aromatic moieties are very sparsely functionalized with phenolic and carboxylic functionalities. Additionally, specific model molecular structures have been identified which are consistent with experimental evidence and are in full agreement with our previously derived meso-model based on solid-state 13C NMR data. Finally, some of the shortcomings of 2D liquid-state NMR for the characterization of humic materials are addressed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0013-936X
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3935-44
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
A comprehensive liquid-state heteronuclear and multidimensional NMR study of Laurentian fulvic acid.
pubmed:affiliation
Department of Biological Sciences, University of Calgary, 2500 University Drive N.W., Calgary, Alberta, Canada, T2N 1N4. rlcook@lsu.edu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't