The reaction of triplet 2-methyl-1,4-naphthoquinone (menadione) with DNA and polynucleotides.
The photoreaction of 2-methyl-1,4-naphthoquinone (MQ, menadione) with DNA and polynucleotides in argon-saturated aqueous solution (pH 7) was studied. Results from laser flash photolysis experiments indicate that triplet quinone reacts with DNA and polyA but not detectably with polyU by one-electron oxidation of the bases of the nucleic acid with formation of the radical anion of the quinone. Irradiation of argon-saturated solutions containing MQ and DNA or polynucleotides (polyU, polyA, polyG or polyC) with 334 nm light leads to an increase in molecular weight for single-stranded DNA, polyA and to a much less extent for polyU. This finding indicates crosslink formation with quantum yields in the range of 10(-5)-10(-3).
Melvin
T
T
Max-Planck-Institut für Strahlenchemie, Mülheim an der Ruhr, Germany. t.melvin@har-rbu.mrc.ac.uk
Bothe
E
E
Schulte-Frohlinde
D
D
D000818:Animals; D002417:Cattle; D004247:DNA / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects; D004277:DNA, Single-Stranded / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D010084:Oxidation-Reduction; D010777:Photochemistry; D010782:Photolysis; D011119:Polynucleotides / Q000378:metabolism* / Q000528:radiation effects; D014812:Vitamin K / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*
D004277:DNA, Single-Stranded; D011119:Polynucleotides; D014812:Vitamin K; D004247:DNA