skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The use of photosensitizers to selectively generate radiation-induced guanine decomposition products

Abstract

Free radicals generated in vivo through biological processes, including photosensitization, may lead to oxidative damage to cellular DNA. Such photosensitizer-mediated damage to DNA occurs through two principal competitive mechanisms, labeled type 1 and type 2, depending on the process by which an excited photosensitizer decays from its triplet state back to the ground state. Type 1 mechanisms involve initial electron or hydrogen transfer by the excited photosensitizer to, or from, the substrate (DNA) to generate free radicals. Type 2 mechanisms involve the initial generation of singlet oxygen by the excited photosensitizer which subsequently reacts with the substrate to generate unstable peroxidic intermediates. Although in both cases the primary target in DNA is the guanine base, the two mechanisms generate a different set of photoproducts. The lesions 2-amino-5-[(3,5-di-O-acetyl-2-deoxy-{beta}-D-erythro-pentofuran-osyl)-amino]-4H-imidazol-4-one and its major decomposition product, 2,2-diamino-4-[(3,5-di-O-acetyl-2-deoxy-{beta}-D-erythro-pentofuranosyl)amino]-5(2H)-oxazolone, have previously been identified and characterized following the exposure of 3{prime},5{prime}-di-O-acetyl-2{prime}-deoxyguanosine to OH radicals in aerated aqueous solution. In this report the authors more fully characterize 2-amino-5-[(2-deoxy-{beta}-D-erythropentofuranosyl)amino]-4H-imidazol-4-one (dIZ) and its major decomposition product, 2,2-diamino-4-[(2-deoxy-{beta}-D-erythro-pentofuranosyl)amino]-5(2H)-oxazolone (dZ), obtained from the {gamma}-radiolysis of the non-acetyled nucleoside, 2{prime}-deoxyguanosine (dG), in aerated aqueous solution.

Authors:
;  [1]; ; ;  [2]
  1. Cross Cancer Inst., Edmonton, Alberta (Canada). Dept. of Radiobiology
  2. Centre d`Etudes Nucleaires de Grenoble (France). Lab. des Lesions des Acides Nucleiques
Publication Date:
OSTI Identifier:
400743
Report Number(s):
CONF-9410280-
ISBN 0-935470-90-5; TRN: 96:030265
Resource Type:
Conference
Resource Relation:
Conference: International workshop on radiation damage in DNA: relationships at early times, Gleneden, OR (United States), 1-6 Oct 1994; Other Information: PBD: 1995; Related Information: Is Part Of Radiation damage in DNA: Structure/function relationships at early times; Fuciarelli, A.F. [ed.] [Pacific Northwest Lab., Richland, WA (United States). Biology and Chemistry Dept.]; Zimbrick, J.D. [ed.] [National Academy of Sciences, Washington, DC (United States). National Research Council]; PB: 460 p.
Country of Publication:
United States
Language:
English
Subject:
56 BIOLOGY AND MEDICINE, APPLIED STUDIES; 55 BIOLOGY AND MEDICINE, BASIC STUDIES; DNA; BIOLOGICAL RADIATION EFFECTS; RADIOSENSITIZERS; PHOTOCHEMICAL REACTIONS; GUANINE; STRUCTURE-ACTIVITY RELATIONSHIPS; GAMMA RADIATION

Citation Formats

Buchko, G W, Weinfeld, M, Berger, M, Cadet, J, and Raoul, S. The use of photosensitizers to selectively generate radiation-induced guanine decomposition products. United States: N. p., 1995. Web.
Buchko, G W, Weinfeld, M, Berger, M, Cadet, J, & Raoul, S. The use of photosensitizers to selectively generate radiation-induced guanine decomposition products. United States.
Buchko, G W, Weinfeld, M, Berger, M, Cadet, J, and Raoul, S. 1995. "The use of photosensitizers to selectively generate radiation-induced guanine decomposition products". United States.
@article{osti_400743,
title = {The use of photosensitizers to selectively generate radiation-induced guanine decomposition products},
author = {Buchko, G W and Weinfeld, M and Berger, M and Cadet, J and Raoul, S},
abstractNote = {Free radicals generated in vivo through biological processes, including photosensitization, may lead to oxidative damage to cellular DNA. Such photosensitizer-mediated damage to DNA occurs through two principal competitive mechanisms, labeled type 1 and type 2, depending on the process by which an excited photosensitizer decays from its triplet state back to the ground state. Type 1 mechanisms involve initial electron or hydrogen transfer by the excited photosensitizer to, or from, the substrate (DNA) to generate free radicals. Type 2 mechanisms involve the initial generation of singlet oxygen by the excited photosensitizer which subsequently reacts with the substrate to generate unstable peroxidic intermediates. Although in both cases the primary target in DNA is the guanine base, the two mechanisms generate a different set of photoproducts. The lesions 2-amino-5-[(3,5-di-O-acetyl-2-deoxy-{beta}-D-erythro-pentofuran-osyl)-amino]-4H-imidazol-4-one and its major decomposition product, 2,2-diamino-4-[(3,5-di-O-acetyl-2-deoxy-{beta}-D-erythro-pentofuranosyl)amino]-5(2H)-oxazolone, have previously been identified and characterized following the exposure of 3{prime},5{prime}-di-O-acetyl-2{prime}-deoxyguanosine to OH radicals in aerated aqueous solution. In this report the authors more fully characterize 2-amino-5-[(2-deoxy-{beta}-D-erythropentofuranosyl)amino]-4H-imidazol-4-one (dIZ) and its major decomposition product, 2,2-diamino-4-[(2-deoxy-{beta}-D-erythro-pentofuranosyl)amino]-5(2H)-oxazolone (dZ), obtained from the {gamma}-radiolysis of the non-acetyled nucleoside, 2{prime}-deoxyguanosine (dG), in aerated aqueous solution.},
doi = {},
url = {https://www.osti.gov/biblio/400743}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Dec 31 00:00:00 EST 1995},
month = {Sun Dec 31 00:00:00 EST 1995}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share: