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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
19
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pubmed:dateCreated |
1988-11-9
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pubmed:abstractText |
We have studied the effects of the recently reported two new metabolites of the antitumor agent VP-16-213, the ortho-dihydroxy derivative or catechol and the ortho-quinone, on the biological activity of single-stranded and double-stranded phi X174 DNA, the binding of the metabolites to calf thymus DNA and the conversion of the catechol into the ortho-quinone. Evidence was obtained for the oxidation of the catechol into the ortho-quinone and for the fact that the ortho-quinone is the metabolite of VP-16-213 responsible for its binding to rat liver microsomal proteins. The catechol and ortho-quinone of VP-16-213 were found to bind 7-9 times more strongly to calf thymus DNA than VP-16-213 itself. In contrast to the parent compound VP-16-213, the catechol as well as the ortho-quinone inactivated both single-stranded (ss) and double-stranded (RF) biologically active phi X174 DNA. The mean T37-values for inactivation of ss and RF phi X174 DNA by 2.2 x 10(-4)M catechol at 37 degrees and pH 7.4 were 96 and 640 min, respectively. Reduction of the ortho-quinone by NADPH cytochrome P-450 reductase resulted in formation of the catechol. The system ortho-quinone/NADPH cytochrome P-450 reductase inactivated ss phi X174 DNA with a mean T37-value of 454 min, and this inactivation was inhibited by DMSO. The mean T37-value for inactivation of ss phi X174 DNA by 1.8 x 10(-4) M ortho-quinone at 37 degrees and pH 4.0 was 24 min. The chemical stability of the ortho-quinone and the extent of inactivation of ss phi X174 DNA by the ortho-quinone were both pH-dependent: at higher pH the ortho-quinone was less stable and gave less inactivation of DNA. The aqueous decomposition product(s) of the ortho-quinone formed at pH 7.4 inactivated ss phi X174 DNA with a mean T37-value of 175 min. The rate of inactivation of RF phi X174 DNA by the ortho-quinone at pH 4.0 was twice as low as the rate of inactivation of ss phi X174 DNA: T37 = 49 min. When using excision repair deficient E. coli mutants (uvrA- or uvrC-), a higher inactivation of RF phi X174 DNA was found: T37 = 29 min for uvrA- E. coli, indicating that a part of the DNA damage introduced by the incubation with ortho-quinone is removed by excision repair.(ABSTRACT TRUNCATED AT 400 WORDS)
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Catechols,
http://linkedlifedata.com/resource/pubmed/chemical/DNA, Single-Stranded,
http://linkedlifedata.com/resource/pubmed/chemical/DNA, Viral,
http://linkedlifedata.com/resource/pubmed/chemical/Etoposide,
http://linkedlifedata.com/resource/pubmed/chemical/Quinones,
http://linkedlifedata.com/resource/pubmed/chemical/catechol
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pubmed:status |
MEDLINE
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pubmed:month |
Oct
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pubmed:issn |
0006-2952
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
37
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
3579-89
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pubmed:dateRevised |
2003-11-14
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pubmed:meshHeading |
pubmed-meshheading:2972290-Animals,
pubmed-meshheading:2972290-Bacteriophage phi X 174,
pubmed-meshheading:2972290-Catechols,
pubmed-meshheading:2972290-DNA, Single-Stranded,
pubmed-meshheading:2972290-DNA, Viral,
pubmed-meshheading:2972290-DNA Damage,
pubmed-meshheading:2972290-Etoposide,
pubmed-meshheading:2972290-Hydrogen-Ion Concentration,
pubmed-meshheading:2972290-Male,
pubmed-meshheading:2972290-Oxidation-Reduction,
pubmed-meshheading:2972290-Protein Binding,
pubmed-meshheading:2972290-Quinones,
pubmed-meshheading:2972290-Rats,
pubmed-meshheading:2972290-Rats, Inbred Strains
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pubmed:year |
1988
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pubmed:articleTitle |
Effects of the ortho-quinone and catechol of the antitumor drug VP-16-213 on the biological activity of single-stranded and double-stranded phi X174 DNA.
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pubmed:affiliation |
Department of Oncology, Free University Hospital, Amsterdam, The Netherlands.
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pubmed:publicationType |
Journal Article
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