Novel spiroindoline HDAC inhibitors: Synthesis, molecular modelling and biological studies

Eur J Med Chem. 2018 Sep 5;157:127-138. doi: 10.1016/j.ejmech.2018.07.069. Epub 2018 Jul 31.


This paper describes the rational development of a series of novel spiroindoline derivatives endowed with selective inhibitory activity on the HDAC6 isoform. A convenient multicomponent one-pot protocol was applied for the assembly of the desired N1-substituted spiroindoline core which allowed a straightforward analoging. Computational studies and in vitro determination of inhibitory potency for the developed compounds against HDAC6 and HDAC1 isoforms were flanked by cell-based studies on histone H3 and α-tubulin acetylation. The effects on cancer cell cycle and apoptosis of the best performing derivatives were assessed on cancer cell lines highlighting a promising antitumor potential. In view of cell-based data and calculated drug-like properties, the selective HDAC6 inhibitor 5b, with a spiroindoline-based hydroxamate bearing a tert-butyl carbamate functionality, was selected to be further investigated for its potential in inhibiting tumor cells migration. It was able to potently inhibit cell migration in SH-SY5Y neuroblastoma cells and did not display toxicity in NIH3T3 mouse fibroblasts. Taken together, these data foster further investigation and optimization for this class of compounds as novel anticancer agents.

Keywords: Antitumor agents; Bioinformatics; Drug design; Enzyme inhibitors; Epigenetics; HDAC.

MeSH terms

  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology*
  • Apoptosis / drug effects
  • Cell Cycle / drug effects
  • Cell Line, Tumor
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Dose-Response Relationship, Drug
  • Drug Screening Assays, Antitumor
  • Histone Deacetylase 1 / antagonists & inhibitors*
  • Histone Deacetylase 1 / metabolism
  • Histone Deacetylase 6 / antagonists & inhibitors*
  • Histone Deacetylase 6 / metabolism
  • Histone Deacetylase Inhibitors / chemical synthesis
  • Histone Deacetylase Inhibitors / chemistry
  • Histone Deacetylase Inhibitors / pharmacology*
  • Humans
  • Models, Molecular
  • Molecular Structure
  • Structure-Activity Relationship


  • Antineoplastic Agents
  • Histone Deacetylase Inhibitors
  • HDAC1 protein, human
  • HDAC6 protein, human
  • Histone Deacetylase 1
  • Histone Deacetylase 6