title: Guanyl-C8-arylamination of DNA by the ultimate carcinogen of 4-nitroquinoline-1-oxide: a spectrophotometric titration.
abstract: Native and denatured DNAs and polynucleotides were modified by 4-acetoxyaminoquinoline-1-oxide, the ultimate carcinogen of 4-nitroquinoline-1-oxide (4 NQO). The N-( deoxyguanosin -C8-yl)-4-aminoquinoline-1-oxide adduct, the so-called "dG III," was quantified on the DNA and on poly(dG-dC) in absorption spectroscopy, by using a spectral property of dG III, i.e., the variation of the absorption spectrum as a function of the pH. Using the "free-dG III" absorption reference spectra, a simple graphic determination of the percentage of dG III was established by recording the absorption spectra of the 4-acetoxyaminoquinoline-1-oxide-modified polymers. It was found that the dG III adduct accounts for about 30% of the total modification in the case of native modified DNA and poly(dG-dC) and for about 70% in the case of denatured modified DNA.
mesh_terms: D015112:4-Nitroquinoline-1-oxide / Q000378:metabolism*; D000634:Aminoquinolines / Q000032:analysis* / Q000378:metabolism*; D002273:Carcinogens / Q000378:metabolism*; D004247:DNA / Q000032:analysis*; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D009600:Nitroquinolines / Q000378:metabolism*; D011089:Polydeoxyribonucleotides / Q000032:analysis; D013053:Spectrophotometry; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000634:Aminoquinolines; D002273:Carcinogens; D009600:Nitroquinolines; D011089:Polydeoxyribonucleotides; C019530:poly(dC-dG); D015112:4-Nitroquinoline-1-oxide; C032982:4-acetoxyaminoquinoline 1-oxide; C032983:N-(deoxyguanosin-C(8)-yl)-4-aminoquinoline 1-oxide; D004247:DNA; D003849:Deoxyguanosine