Palau'amine and related oroidin alkaloids dibromophakellin and dibromophakellstatin inhibit the human 20S proteasome

J Nat Prod. 2012 May 25;75(5):980-5. doi: 10.1021/np300231f. Epub 2012 May 16.

Abstract

We report herein that the oroidin-derived alkaloids palau'amine (1), dibromophakellin (2), and dibromophakellstatin (3) inhibit the proteolytic activity of the human 20S proteasome as well as the (i)20S immunoproteasome catalytic core. Palau'amine is found to prevent the degradation of ubiquitinylated proteins, including IκBα, in cell culture, which may be indicative of the potential mechanism by which these agents exhibit their exciting cytotoxic and immunosuppressive properties.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaloids / chemistry
  • Alkaloids / pharmacology*
  • Guanidines / chemistry
  • Guanidines / pharmacology*
  • HeLa Cells
  • Heterocyclic Compounds, 4 or More Rings / chemistry
  • Heterocyclic Compounds, 4 or More Rings / pharmacology*
  • Humans
  • Imidazoles / chemistry
  • Imidazoles / pharmacology*
  • Microscopy, Confocal
  • NF-kappa B / metabolism
  • Proteasome Endopeptidase Complex / chemistry
  • Proteasome Inhibitors*
  • Pyrroles / chemistry
  • Pyrroles / pharmacology*
  • Spiro Compounds / chemistry
  • Spiro Compounds / pharmacology*
  • Stereoisomerism

Substances

  • Alkaloids
  • Guanidines
  • Heterocyclic Compounds, 4 or More Rings
  • Imidazoles
  • NF-kappa B
  • Proteasome Inhibitors
  • Pyrroles
  • Spiro Compounds
  • dibromophakellin
  • dibromophakellstatin
  • palau'amine
  • Proteasome Endopeptidase Complex
  • oroidin