Design, synthesis, and activity evaluation of broad-spectrum small-molecule inhibitors of anti-apoptotic Bcl-2 family proteins: characteristics of broad-spectrum protein binding and its effects on anti-tumor activity

Bioorg Med Chem Lett. 2012 Jan 1;22(1):39-44. doi: 10.1016/j.bmcl.2011.11.101. Epub 2011 Dec 1.


On the basis of the comparison of the structure of the Bim BH3: Bcl-x(L) complex and that of the ABT-737: Bcl-x(L) complex, a series of class A compounds were designed. These compounds had the basic skeleton of ABT-737 and the h2 residues of Bim BH3. These residues had shown themselves to be relevant to Bim BH3's broad-spectrum binding properties in saturation mutagenesis assays. Unlike ABT-737, which is a selective inhibitor of anti-apoptotic members of the Bcl-2 protein family, the class A compounds showed broad-spectrum binding activity to target proteins similar to those of Bim BH3 peptide. Then class B compounds were synthesized by modifying the structure of the most effective class A compound, A-4. Most of these class B compounds showed better binding affinity to the target proteins than the class A compounds had. They also showed themselves more effective than ABT-737 at inhibiting growth in multiple tumor cell lines known to express Bcl-x(L), Bcl-2, and Mcl-1 proteins at high levels. Compounds B-11 and B-12 had the strongest anti-tumor activity of any compounds we produced. This study suggests that it is feasible to design small-molecule inhibitors based on the structure of Bim BH3, which shows broad-spectrum binding to Bcl-x(L), Bcl-2, and Mcl-1 proteins. Our results also suggest that the broad-spectrum properties of small-molecule inhibitors binding to target proteins play a critical role in inhibiting the growth of many tumor cells. Finally, our study provides a series of lead compounds that merit further research into anti-cancer therapeutics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / pharmacology*
  • Apoptosis*
  • Biphenyl Compounds / pharmacology
  • Cell Line, Tumor
  • Chemistry, Pharmaceutical / methods*
  • Drug Design*
  • Drug Screening Assays, Antitumor
  • Humans
  • Models, Chemical
  • Mutagenesis
  • Myeloid Cell Leukemia Sequence 1 Protein
  • Nitrophenols / pharmacology
  • Piperazines / pharmacology
  • Protein Binding
  • Proto-Oncogene Proteins c-bcl-2 / antagonists & inhibitors*
  • Proto-Oncogene Proteins c-bcl-2 / chemistry
  • Sulfonamides / pharmacology
  • bcl-X Protein / antagonists & inhibitors


  • ABT-737
  • Antineoplastic Agents
  • BCL2L1 protein, human
  • Biphenyl Compounds
  • Myeloid Cell Leukemia Sequence 1 Protein
  • Nitrophenols
  • Piperazines
  • Proto-Oncogene Proteins c-bcl-2
  • Sulfonamides
  • bcl-X Protein