Synthesis, DNA binding, and Leishmania topoisomerase inhibition activities of a novel series of anthra[1,2-d]imidazole-6,11-dione derivatives

Nine novel anthra[1,2-d]imidazole-6,11-diones, differing in their side chain, were synthesized. UV-vis spectroscopy and viscometric titrations of these molecules with duplex DNA were used to assess their binding with DNA. Five of the nine compounds showed high inhibition activity against topoisomerase I of Leishmania donovani, with the one bearing the tetrazole side chain exhibiting an IC50 - 1 mu M. The inhibition activities were not related with their DNA binding affinity and depended on the nature of the side chain.