Remarkable enhancement in the DNA-binding ability of C2-fluoro substituted pyrrolo[2,1-c][1,4]benzodiazepines and their anticancer potential

Bioorg Med Chem. 2009 Feb 15;17(4):1557-72. doi: 10.1016/j.bmc.2008.12.068. Epub 2009 Jan 6.

Abstract

C2-Fluoro substituted DC-81, and its dimers that comprise of two C2-fluoro substituted DC-81 subunits tethered to their C8-position through simple alkane spacers as well as piperazine moiety side-armed with symmetrical alkyloxy spacers have been designed and synthesized. These fluoro substituted pyrrolo[2,1-c][1,4]benzodiazepines have shown remarkable DNA-binding ability and most of them possess promising anticancer activity, having GI(50) values in micromolar to nanomolar concentration range. DNA thermal denaturation studies show that some of these compounds (14a-c and 15) increase the DeltaT(m) values in the range of 28.9-38 degrees C, and this is further confirmed by the restriction endonuclease studies. This study illustrates the importance of introducing fluoro substitution at the C2-position apart from the incorporation of a piperazine ring in between the alkyloxy linker for enhancement of the DNA-binding ability in comparison to DSB-120 and SJG-136 (DeltaT(m)=10.2 and 25.7 degrees C). Moreover, the variations in the DNA-binding ability with respect to fluoro substitution in this class of dimers has been investigated by molecular modeling studies. Some representative C2-fluoro substituted dimers (8a and 14a) have also exhibited significant anticancer activity in the 60 cancer cell line assay of the National Cancer Institute (NCI).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / metabolism
  • Antineoplastic Agents / pharmacology*
  • Benzodiazepines / metabolism*
  • Benzodiazepines / pharmacology*
  • Cell Line, Tumor
  • DNA / drug effects*
  • DNA / metabolism*
  • DNA Restriction Enzymes / metabolism
  • Drug Design
  • Drug Screening Assays, Antitumor
  • Humans
  • Models, Molecular
  • Pyrrolidines / metabolism
  • Pyrrolidines / pharmacology*
  • Structure-Activity Relationship

Substances

  • Antineoplastic Agents
  • Pyrrolidines
  • Benzodiazepines
  • DNA
  • DNA Restriction Enzymes