Linked Life Data

18215490

Source:http://linkedlifedata.com/resource/pubmed/id/18215490

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2008-4-11
pubmed:abstractText
Maytenus ilicifolia is an important plant in Brazilian folk medicine, used in many gastric disorder treatments. Low molecular weight components present in the leaves have been characterized as afzelechin, epiafzelechin, catechin, epicatechin, gallocatechin and epigallocatechin, as detected by HPLC and ESI-MS. Condensed tannins have also been found, consisting of di-, tri-, tetra-, and penta-, hexa, and heptamers. ESI-MS analyses were performed in positive and negative ionization modes, and in contrast with other investigations, negative ionization improved sensitivity for obtaining molecular ions. Moreover, the tandem-MS profile with negative detection provided characteristic fragments, such as those found at m/z 543 [(epi)afzelechin-(epi)afzelechin], m/z 561 [(epi)afzelechin-(epi)catechin], and m/z 577 [(epi)catechin-(epi)catechin] or [(epi)afzelechin-(epi)gallocatechin]. The analysis of the fragments also indicated the presence of additional ether linkage between C2 and C7, present in A-Type proanthocyanidins, and were identified at m/z 559 [(epi)afzelechin-(epi)catechin], m/z 575 [(epi)catechin-(epi)catechin] or [(epi)afzelechin-(epi)gallocatechin] and at m/z 591, [(epi)catechin-(epi)gallocatechin]. CID-fragmentation was used for tannins sequencing, as well as 3D NMR HMQC-TOCSY and COSY, which provided fingerprint assignments for identification of cathechin at delta 4.55/82.1 (H-2/C-2), 3.96/68.1 (H-3/C-3) and 2.82-2.50/27.7 (H-4a-H-4b/C-4), and epicathechin delta 4.78/79.1 (H-2/C-2), 4.15/66.7 (H-3/C-3) and 2.82-2.73/28.5 (H-4a-H-4b/C-4). Since HMQC-TOCSY gives a high resolution heteronuclear connectivity, it is useful for identification of other cis-trans isomers present in complex flavonoid mixtures.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0731-7085
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
47
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
59-67
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
HPLC/ESI-MS and NMR analysis of flavonoids and tannins in bioactive extract from leaves of Maytenus ilicifolia.
pubmed:affiliation
Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, CP 19046, CEP 81531-980, Curitiba-PR, Brazil.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't