Solution-phase synthesis and biological evaluation of triostin A and its analogues

Org Biomol Chem. 2016 Feb 14;14(6):2090-111. doi: 10.1039/c5ob02505b.

Abstract

Triostin A is a biosynthetic precursor of echinomycin which is one of the most potent hypoxia inducible factor 1 (HIF-1) inhibitors. An improved solution-phase synthesis of triostin A on a preparative scale has been achieved in 17.5% total yield in 13 steps. New analogues of triostin A with various aromatic chromophores, oxidized intra-peptide disulfide bridges and diastereoisomeric cyclic depsipeptide cores were also successfully synthesized. All analogues had a significant inhibitory effect on HIF-1 transcriptional activation in hypoxia and cytotoxicity on MCF-7 cells, with the exception of the derivatives containing a naphthalene chromophore or a thiosulfonate bridge. For the first time, triostin A, echinomycin and the thiosulfinate analogue of triostin A have been revealed to inhibit not only DNA binding of HIF-1 but also HIF-1α protein accumulation in MCF-7 cells. Furthermore, the thiosulfinate analogue and triostin A exhibited a hypoxia-selective cytotoxicity on MCF-7 cells. The improved solution-phase synthetic procedure described herein will contribute to the development of diverse bicyclic depsipeptide drug candidates with the potential to act as novel anti-cancer agents targeting hypoxic tumor microenvironments.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology*
  • Cell Hypoxia / drug effects*
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • DNA, Neoplasm / metabolism
  • Dose-Response Relationship, Drug
  • Drug Screening Assays, Antitumor
  • HEK293 Cells
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / antagonists & inhibitors
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • MCF-7 Cells
  • Models, Molecular
  • Molecular Structure
  • Protein Binding / drug effects
  • Quinoxalines / chemical synthesis
  • Quinoxalines / chemistry
  • Quinoxalines / pharmacology
  • Solutions
  • Structure-Activity Relationship

Substances

  • Antineoplastic Agents
  • DNA, Neoplasm
  • HIF1A protein, human
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Quinoxalines
  • Solutions
  • triostin A