Linked Life Data

1796117

Source:http://linkedlifedata.com/resource/pubmed/id/1796117

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1992-4-6
pubmed:abstractText
The 5 microM hematoporphyrin-sensitized photooxidation of 1,3-diphenylisobenzofuran (DPBF) was studied in homogeneous ethanolic solutions and in aqueous dispersions of unilamellar liposomes of dipalmitoylphosphatidylcholine; both the porphyrin and DPBF are embedded in the phospholipid bilayer. The rate and quantum yield of DPBF photooxidation were found to increase upon increasing the substrate concentration and were higher in the liposome system, while they were unaffected by the fluidity of the phospholipid bilayer. Time-resolved spectroscopic measurements showed that the photooxidation of DPBF in ethanol solution proceeds by a type II O2(1 delta g)-involving mechanism. In the liposomal vesicles the high local concentration of hematoporphyrin (Hp) and DPBF in the phospholipid bilayer (ca 2000-fold higher than the stoichiometric concentration) enhances the probability of energy transfer from triplet Hp to DPBF with generation of triplet DPBF; hence O2 (1 delta g) formation can be promoted by both triplet Hp and triplet DPBF. A minor fraction of triplet DPBF quenchings appears to generate radical species which propagate DPBF damage by chain reaction.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0031-8655
pubmed:author
pubmed:issnType
Print
pubmed:volume
54
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
633-7
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Studies on the mechanism of the hematoporphyrin-sensitized photooxidation of 1,3-diphenylisobenzofuran in ethanol and unilamellar liposomes.
pubmed:affiliation
Department of Biology, University of Padova, Italy.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't