Synthesis and discovery of water-soluble microtubule targeting agents that bind to the colchicine site on tubulin and circumvent Pgp mediated resistance

J Med Chem. 2010 Nov 25;53(22):8116-28. doi: 10.1021/jm101010n. Epub 2010 Oct 25.


Two classes of molecules were designed and synthesized based on a 6-CH(3) cyclopenta[d]pyrimidine scaffold and a pyrrolo[2,3-d]pyrimidine scaffold. The pyrrolo[2,3-d]pyrimidines were synthesized by reacting ethyl 2-cyano-4,4-diethoxybutanoate and acetamidine, which in turn was chlorinated and reacted with the appropriate anilines to afford 1 and 2. The cyclopenta[d]pyrimidines were obtained from 3-methyladapic acid, followed by reaction with acetamidine to afford the cyclopenta[d]pyrimidine scaffold. Chlorination and reaction with appropriate anilines afforded (±)-3·HCl-(±)-7·HCl. Compounds 1 and (±)-3·HCl had potent antiproliferative activities in the nanomolar range. Compound (±)-3·HCl is significantly more potent than 1. Mechanistic studies showed that 1 and (±)-3·HCl cause loss of cellular microtubules, inhibit the polymerization of purified tubulin, and inhibit colchicine binding. Modeling studies show interactions of these compounds within the colchicine site. The identification of these new inhibitors that can also overcome clinically relevant mechanisms of drug resistance provides new scaffolds for colchicine site agents.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B, Member 1 / physiology*
  • Animals
  • Binding Sites
  • Cattle
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Colchicine / metabolism*
  • Drug Resistance, Neoplasm*
  • Drug Screening Assays, Antitumor
  • Humans
  • Models, Molecular
  • Protein Binding
  • Pyrimidines / chemical synthesis*
  • Pyrimidines / chemistry
  • Pyrimidines / pharmacology
  • Pyrroles / chemical synthesis*
  • Pyrroles / chemistry
  • Pyrroles / pharmacology
  • Solubility
  • Stereoisomerism
  • Structure-Activity Relationship
  • Tubulin / metabolism*
  • Tubulin Modulators / chemical synthesis*
  • Tubulin Modulators / chemistry
  • Tubulin Modulators / pharmacology
  • Water


  • ATP Binding Cassette Transporter, Subfamily B, Member 1
  • N-(4-methoxyphenyl)-N,2,6-trimethyl-6,7-dihydro-5H-cyclopenta(d)pyrimidin-4-amine
  • N-(4-methoxyphenyl)-N,2-dimethyl-7H-pyrrolo(2,3-d)pyrimidin-4-amine
  • Pyrimidines
  • Pyrroles
  • Tubulin
  • Tubulin Modulators
  • Water
  • Colchicine