New spiro-acridines: DNA interaction, antiproliferative activity and inhibition of human DNA topoisomerases

Two new spiro-acridines were synthesized by introducing cyano-N-acylhydrazone between the acridine and phenyl rings followed by spontaneous cyclization. The final compounds (E)-1'-(benzylideneamino)-5'-oxo-1',5'-dihydro-10H-spiro[acridine-9,2'-pyrrole]-4'-carbonitrile (AMTAC-01) and (E)-1'-((4-methoxybenzylidene)amino)-5'-oxo-1',5'-dihydro-10H-spiro[acridine-9,2'-pyrrole]-4'-carbonitrile (AMTAC-02) were evaluated for their interactions with calf thymus DNA, antiproliferative and human topoisomerase I and II alpha inhibitory activities. Both compounds presented ability to bind DNA. The binding constant determined by UV-vis spectroscopy was found to be 10(4)M(-1). Antiproliferative assay demonstrated that AMTAC-01 and AMTAC-02 were most active against prostate and melanoma tumor cell lines, respectively. The compound did not present Topo I inhibitory activity. However, both derivatives displayed topoisomerase IIa inhibitory activity comparable to amsacrine, and AMTAC-02 was more potent than AMTAC-01 with methoxy substituent group on phenyl ring. This study demonstrates that the new derivatives are promising molecules with topoisomerase II alpha inhibitory and antiproliferative activities. (C) 2016 Elsevier B.V. All rights reserved.