Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2007-10-1
pubmed:abstractText
The hyphenated technique, high-performance liquid chromatography-solid-phase extraction-nuclear magnetic resonance spectroscopy (HPLC-SPE-NMR), has been applied for rapid identification of novel natural products in crude extracts of Hubertia ambavilla and Hubertia tomentosa. The technique allowed full or partial identification of all major extract constituents and demonstrated the presence of unusual quinic acid derivatives containing the (1-hydroxy-4-oxocyclohexa-2,5-dienyl)acetyl residue that exhibit strongly coupled ABXY patterns, the parameters of which were obtained by spin simulations. Using homo- and heteronuclear 2D NMR data acquired in the HPLC-SPE-NMR mode, complete structure determination of three new natural products, i.e., 3,5-di-O-caffeoyl-4-O-[(1-hydroxy-4-oxocyclohexa-2,5-dienyl)acetyl]quinic acid (1), its 2-hydroxy derivative (2), and 3,5-di-O-caffeoyl-4-O-[(4-hydroxyphenyl)acetyl]quinic acid (3), was performed. Finally, targeted isolation of 1 was achieved by SPE fractionation and preparative HPLC, followed by evaluation of its antioxidant and antimicrobial activity. In contrast to chlorogenic acid and 3,5-di-O-caffeoylquinic acid, which act as antioxidants, compound 1 proved at the same conditions to possess prooxidant activity in an assay evaluating the oxidation of human low-density lipoprotein induced by Cu(2+).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0163-3864
pubmed:author
pubmed:issnType
Print
pubmed:volume
70
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1472-7
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Targeted natural product isolation guided by HPLC-SPE-NMR: constituents of Hubertia species.
pubmed:affiliation
Department of Medicinal Chemistry, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't