Linked Life Data

20879715

Source:http://linkedlifedata.com/resource/pubmed/id/20879715

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
41
pubmed:dateCreated
2010-10-14
pubmed:abstractText
The chemical equilibria of the pyranomalvidin-3-glucosides linked to (+)-catechin, (-)-epicatechin, and catechol moieties (and the respective coumaroylglucoside compounds) were established by means of UV-vis spectroscopy. The conjugated double bonds among pyranic rings C and D provide a higher electronic delocalization that prevents the nucleophilic attack of water at position 2. Consequently, besides flavylium cation (AH(+)), the bases A, A(-), and A(2-) have been identified by increasing pH, and the respective acidity constants were determined by spectrophotometry. The formation of dimers at higher concentration was observed for pyranomalvidin-3-O-coumaroylglucoside-(+)-catechin, and the respective data treated by the exciton model suggests the formation of a dimer where the monomers form J-type aggregates with the dipolar moments in opposite directions and rotated by 174° at a distance of 5.2 Å (from the center).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1520-5207
pubmed:author
pubmed:issnType
Electronic
pubmed:day
21
pubmed:volume
114
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
13232-40
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Establishment of the chemical equilibria of different types of pyranoanthocyanins in aqueous solutions: evidence for the formation of aggregation in pyranomalvidin-3-O-coumaroylglucoside-(+)-catechin.
pubmed:affiliation
Centro de Investigac?a?o em Qui?mica, Departamento de Qui?mica, Faculdade de Cie?ncias, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't