Interactions of some nitro-derivatives of substituted 9-aminoacridine with DNA.

The mechanism of the biological activity of the 1-nitro and 2-nitro aminoacridine derivatives containing the dimethylaminopropyl side chain was studied. RNA synthesis in the isolated rat liver nuclei was only slightly influenced by both compounds. They do not differ in their ability to form an intercalative complex with DNA. Only the 1-nitro derivative exhibited strong inhibitory effect on RNA biosynthesis and caused distinct ultrastructural changes (nucleolar segregation, chromatine margination etc.) in a living cell. The 1-nitro derivative binds covalently to DNA in vivo resulting in crosslink formation. It is concluded that the biological activity of 1-nitro acridine derivatives depends more on their crosslinking activity than on their ability to intercalate into DNA.