Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3-4
pubmed:dateCreated
2005-8-8
pubmed:abstractText
The oxidative modification of lipoprotein particles is an important step in atherogenesis. Estrogens are known to be powerful antioxidants independently of their binding to the estrogen receptors and the hormonal functions. We explored the structural determinants for the antioxidant activity of a large number of estrogen derivatives (n=43) in an aqueous lipoprotein solution in vitro by monitoring formation of conjugated dienes. Our results indicate that estrogen derivatives with an unsubstituted A-ring phenolic hydroxyl group with one or two adjacent methoxy groups provide strongest antioxidant protection of low density lipoprotein (LDL) and high density lipoprotein (HDL). The electron donating methoxy groups may enhance the antioxidant effect by weakening the phenolic OH bond and providing stability to the formed phenoxyl radical. With some exceptions, compounds completely lacking unsubstituted hydroxyl groups in the A-ring exhibited no antioxidant effect, e.g. the most hydrophilic "tetrol" compound with three unsubstituted A-ring hydroxyl groups had no antioxidant effect. Moreover, additional hydroxyl groups in the B-, C- or D-ring seemed to weaken the antioxidant effect. Accordingly, both the presence of unsubstituted hydroxyl groups and adjacent substituents, as well as the lipophilicity of the derivatives determine the antioxidant activity of estrogen derivatives in aqueous lipoprotein solutions.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0960-0760
pubmed:author
pubmed:issnType
Print
pubmed:volume
96
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
271-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Estrogen A-ring structure and antioxidative effect on lipoproteins.
pubmed:affiliation
Department of Medicine, University of Helsinki, 00014 Helsinki, Finland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't