DNA adduct formation by 7-methoxy-2-nitro-naphtho[2,1-b]furan (R7000), an extremely potent mutagen.

The effects on DNA, in bacteria, of 7-methoxy-2-nitro-naphtho[2,1-b]furan (R7000), a very potent genotoxic product from the 2-nitronaphthofuran series, were investigated with two different approaches: (i) measurement of the binding of the radiolabelled mutagen to DNA and (ii) detection by the '32P-postlabelling' method of DNA adducts following treatment with unlabelled mutagens. The covalent binding of R7000 to DNA in Escherichia coli was demonstrated by both methods, and in the latter case it was found to involve the formation of nine different adducts. Formation of adducts by R7000 was shown to require metabolic activation of the compound.