Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1992-7-30
pubmed:abstractText
Psoralens and other furocoumarins currently used in PUVA photochemotherapy are shown to have, to a variable extent, the ability to hasten the rate of ultraviolet-induced photooxidation of alpha-tocopherol (alpha-T) in ethanol or ethanol-phosphate buffer (pH 6.8). The sensitizing effect varies significantly with the substrate concentration and the nature of the furocoumarin used, and is dependent on the presence of oxygen. Scavengers of singlet oxygen, e.g., sodium azide, markedly inhibit the psoralen-sensitized photooxidation of alpha-T, whereas superoxide dismutase exerts an opposite, accelerating effect on the reaction rate. Catalase has no significant influence on the kinetics of alpha-T decay. Analysis of the products formed by psoralen-sensitized photooxidation of alpha-T in ethanol-phosphate buffer showed the presence of alpha-tocopherolquinone, its 2,3-epoxide and two related compounds containing the 7-oxaspiro[4.5]dec-1-ene-3,6-dione ring system. The nature of these products, coupled with the results of the kinetic experiments, suggest that psoralens induce a type II, oxygen-dependent photodegradation of alpha-T primarily mediated by singlet oxygen.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
1116
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
291-6
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Photodynamic degradation of vitamin E induced by psoralens.
pubmed:affiliation
Department of Organic and Biological Chemistry, University of Naples, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't