A new class of DNA intercalator and photocleaver: Bis-naphthalimides with bromo and nitro substituents

Three bis-naphthalimides with bromo and nitro substitutents and different long linker arms have been synthesized and their excellent DNA intercalating and cleaving activities are reported. The difference of their intercalation activities is not quite big, but the cleavage activity of the bis-naphthalimide with 3-nitro and 4-bromo substituted groups and a longer aminoalkyl linker is obviously higher than that of the other two bis-naphthalimides: one with a 3-nitro and a 4-bromo substituted groups and a shorter alkyl linker, the other only with two 4-bromo substituted groups and a longer aminoalkyl linker.