Lead optimization and biological evaluation of fragment-based cN-II inhibitors

Eur J Med Chem. 2019 Apr 15;168:28-44. doi: 10.1016/j.ejmech.2019.02.040. Epub 2019 Feb 14.


The development of cytosolic 5'-nucleotidase II (cN-II) inhibitors is essential to validate cN-II as a potential target for the reversion of resistance to cytotoxic nucleoside analogues. We previously reported a fragment-based approach combined with molecular modelling, herein, the selected hit-fragments were used again in another computational approach based on the Ilib-diverse (a software enabling to build virtual molecule libraries through fragment based de novo design) program to generate a focused library of potential inhibitors. A molecular scaffold related to a previously identified compound was selected and led to a novel series of compounds. Ten out of nineteen derivatives showed 50-75% inhibition on the purified recombinant protein at 200 μM and among them three derivatives (12, 13 and 18) exhibited Ki in the sub-millimolar range (0.84, 2.4 and 0.58 mM, respectively). Despite their only modest potency, the cN-II inhibitors showed synergistic effects when used in combination with cytotoxic purine nucleoside analogues on cancer cells. Therefore, these derivatives represent a family of non-nucleos(t)idic cN-II inhibitors with potential usefulness to overcome cancer drug resistance especially in hematological malignancies in which cN-II activity has been described as an important parameter.

Keywords: 5′-nucleotidase; Cancer; Enzyme inhibitor.

MeSH terms

  • 5'-Nucleotidase / antagonists & inhibitors*
  • 5'-Nucleotidase / metabolism
  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology*
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Crystallography, X-Ray
  • Dose-Response Relationship, Drug
  • Drug Screening Assays, Antitumor
  • HL-60 Cells
  • Humans
  • Models, Molecular
  • Molecular Structure
  • Purines / chemical synthesis
  • Purines / chemistry
  • Purines / pharmacology*
  • Structure-Activity Relationship


  • Antineoplastic Agents
  • Purines
  • 5'-Nucleotidase
  • NT5C2 protein, human
  • purine