| Photosensitized generation of superoxide radical in aprotic solvents: an EPR and spin trapping study. | |
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MedLine Citation:
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PMID: 8282230 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The UV or visible irradiation of pigments such as curcumin, anthralin, benzanthrone, 1,8-dihydroxyanthraquinone, and rose bengal- or eosine-complexes with cationic surfactants in aerated aprotic solvents, such as benzene, toluene, acetone, n-heptane, cyclohexane, in the presence of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) generates EPR spectra with hyperfine splitting constants (hfsc's) aN = 12.75 G, a beta H = 10.50 G, a gamma H = 1.26 G in toluene, 12.83 G, 10.64 G, 1.24 G in benzene, 12.75 G, 10.19 G, 1.35 G in acetone and 12.54 G, 10.46 G, 1.38 G in n-heptane and cyclohexane. These spectra are similar to those observed when DMPO reacts with 18-crown-6 ether-solubilized KO2 in the respective solvents and suggests that the photoinduced EPR spectra can be safely assigned to the DMPO/superoxide radical adduct (1). A correlation between the hfsc's of 1 and solvent parameters, the solvent acceptor number AN and the Kosower Z value, has been evaluated in terms of its usefulness for the identification of the DMPO/superoxide adduct in organic media. |
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Authors:
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K Reszka; P Bilski; R H Sik; C F Chignell |
Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Free radical research communications Volume: 19 Suppl 1 ISSN: 8755-0199 ISO Abbreviation: Free Radic. Res. Commun. Publication Date: 1993 |
Date Detail:
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Created Date: 1994-02-16 Completed Date: 1994-02-16 Revised Date: 2000-12-18 |
Medline Journal Info:
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Nlm Unique ID: 8709453 Medline TA: Free Radic Res Commun Country: SWITZERLAND |
Other Details:
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Languages: eng Pagination: S33-44 Citation Subset: IM |
Affiliation:
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Laboratory of Molecular Biophysics, National Institute of Environmental Health Sciences, National Institute of Health, Research Triangle Park, North Carolina 27709. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Photochemistry Solvents Spin Labels Superoxides / chemistry* |
| Chemical | |
Reg. No./Substance:
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0/Solvents; 0/Spin Labels; 11062-77-4/Superoxides |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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