The invention described herein pertains to substituted azaindenoisoquinoline compounds, in particular 7-, 8-, 9-, and 10-azaindenoisoquinoline compounds, which are inhibitors of topoisomerase I, processes and intermediates for their syntheses, pharmaceutical compositions of the compounds, and methods of using them in the treatment of cancer.
7-Azaindenoisoquinolines as Topoisomerase I Inhibitors and Potential Anticancer Agents
作者:Evgeny Kiselev、Sean DeGuire、Andrew Morrell、Keli Agama、Thomas S. Dexheimer、Yves Pommier、Mark Cushman
DOI:10.1021/jm200719v
日期:2011.9.8
A series of 7-azaindenoisoquinoline topoisomerase I (Top 1) inhibitors have been prepared to investigate the effect of increased electron affinity of the aromatic system on the ability to stabilize the Top1-DNA cleavage complex. Ab initio calculations suggest that introduction of nitrogen into the aromatic system of the indenoisoquinolines would facilitate charge transfer complex formation with DNA, thus improving the pi-pi stacking interactions. The present study shows that 7-azaindenoisoquinolines demonstrate improved water solubility without any decrease in Top1 inhibitory activity or cytotoxicity. Analysis of the biological results reveals that smaller lactam ring substituents enable intercalation into both free DNA and Top1-DNA cleavage complex, whereas larger substituents only allow binding to the cleavage complex but not free DNA. Free DNA binding suppresses Top1-catalyzed DNA cleavage at high drug concentrations, whereas DNA cleavage and inhibition of religation occurs at low drug concentration.