Synthesis of mixed (E,Z)-, (E)-, and (Z)-norendoxifen with dual aromatase inhibitory and estrogen receptor modulatory activities

J Med Chem. 2013 Jun 13;56(11):4611-8. doi: 10.1021/jm400364h. Epub 2013 Jun 3.

Abstract

The first synthesis of the tamoxifen metabolite norendoxifen is reported. This included syntheses of (E)-norendoxifen, (Z)-norendoxifen, and (E,Z)-norendoxifen isomers. (Z)-Norendoxifen displayed affinity for aromatase (Ki 442 nM), estrogen receptor-α (EC50 17 nM), and estrogen receptor-β (EC50 27.5 nM), while the corresponding values for (E)-norendoxifen were aromatase (Ki 48 nM), estrogen receptor-α (EC50 58.7 nM), and estrogen receptor-β (EC50 78.5 nM). Docking and energy minimization studies were performed with (E)-norendoxifen on aromatase, and the results provide a foundation for structure-based drug design. The oral pharmacokinetic parameters for (E,Z)-norendoxifen were determined in mice, and (Z)-norendoxifen was found to result in significantly higher plasma concentrations and exposures (AUC values) than (E)-norendoxifen. The affinities of both isomers for aromatase and the estrogen receptors, as well as the pharmacokinetic results, support the further development of norendoxifen and its analogues for breast cancer treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Animals
  • Antineoplastic Agents / chemical synthesis*
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology
  • Aromatase Inhibitors / chemical synthesis*
  • Aromatase Inhibitors / chemistry
  • Aromatase Inhibitors / pharmacology
  • Biological Availability
  • Estrogen Receptor Modulators / chemical synthesis*
  • Estrogen Receptor Modulators / chemistry
  • Estrogen Receptor Modulators / pharmacology
  • Estrogen Receptor alpha / metabolism
  • Estrogen Receptor beta / metabolism
  • Humans
  • Mice
  • Mice, Inbred NOD
  • Mice, SCID
  • Models, Molecular
  • Protein Binding
  • Stereoisomerism
  • Structure-Activity Relationship
  • Tamoxifen / analogs & derivatives*
  • Tamoxifen / chemical synthesis
  • Tamoxifen / chemistry
  • Tamoxifen / pharmacology

Substances

  • Antineoplastic Agents
  • Aromatase Inhibitors
  • Estrogen Receptor Modulators
  • Estrogen Receptor alpha
  • Estrogen Receptor beta
  • N,N-didesmethyl-4-hydroxytamoxifen
  • Tamoxifen