Linked Life Data

9860047

Source:http://linkedlifedata.com/resource/pubmed/id/9860047

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1999-2-23
pubmed:abstractText
GC-MS is a widely used tool to measure oxidative DNA damage because of its ability to identify a wide range of base modification products. However, it has been suggested that the derivatization procedures required to form volatile products prior to GC-MS analysis can sometimes produce artifactual formation of certain base oxidation products, although these studies did not replicate previously-used reaction conditions, e.g. they failed to remove air from the derivatization vials. A systematic examination of this problem revealed that levels of 8-hydroxyguanine, 8-hydroxyadenine, 5-hydroxycytosine and 5-(hydroxymethyluracil) in commercial calf thymus DNA determined by GC-MS are elevated by increasing the temperature at which derivatization is performed in our laboratory. In particular, 8-hydroxyguanine levels after silylation at 140 degrees C were raised 8-fold compared to derivatization at 23 degrees C. Experiments on the derivatization of each undamaged base revealed that the artifactual oxidation of guanine, adenine, cytosine and thymine respectively was responsible. Formation of the above products was potentiated by not purging with nitrogen prior to derivatization. Increasing the temperature to 140 degrees C or allowing air to be present during derivatization did not significantly increase levels of the other oxidized bases measured. This work suggests that artifactual oxidation during derivatization is restricted to certain products (8-hydroxyguanine, 8-hydroxyadenine, 5-hydroxycytosine and 5-[hydroxymethyluracil]) and can be decreased by reducing the temperature of the derivatization reaction to 23 degrees C and excluding as much air possible. Despite some recent reports, we were easily able to detect formamidopyrimidines in acid-hydrolyzed DNA. Artifacts of derivatization are less marked than has been claimed in some papers and may vary between laboratories, depending on the experimental procedures used, in particular the efficiency of exclusion of O2 during the derivatization process.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/5-hydroxycytosine, http://linkedlifedata.com/resource/pubmed/chemical/5-hydroxymethyluracil, http://linkedlifedata.com/resource/pubmed/chemical/8-hydroxyadenine, http://linkedlifedata.com/resource/pubmed/chemical/8-hydroxyguanine, http://linkedlifedata.com/resource/pubmed/chemical/Adenine, http://linkedlifedata.com/resource/pubmed/chemical/Cytosine, http://linkedlifedata.com/resource/pubmed/chemical/DNA, http://linkedlifedata.com/resource/pubmed/chemical/Guanine, http://linkedlifedata.com/resource/pubmed/chemical/Hydantoins, http://linkedlifedata.com/resource/pubmed/chemical/Nitrogen, http://linkedlifedata.com/resource/pubmed/chemical/Pentoxyl, http://linkedlifedata.com/resource/pubmed/chemical/Purines, http://linkedlifedata.com/resource/pubmed/chemical/Pyrimidines
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1071-5762
pubmed:author
pubmed:issnType
Print
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
321-30
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Determination of oxidative DNA base damage by gas chromatography-mass spectrometry. Effect of derivatization conditions on artifactual formation of certain base oxidation products.
pubmed:affiliation
International Antioxidant and Neurodegenerative Disease Research Centres, Pharmacology Group, University of London King's College, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't