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

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-? (EC50 17 nM), and estrogen receptor-? (EC50 27.5 nM), while the corresponding values for (E)-norendoxifen were aromatase (Ki 48 nM), estrogen receptor-? (EC50 58.7 nM), and estrogen receptor-? (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.

SUBMITTER: Lv W 

PROVIDER: S-EPMC4043309 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature