Assessing the trypanocidal potential of natural and semi-synthetic diketopiperazines from two deep water marine-derived fungi

Bioorg Med Chem. 2010 Apr 1;18(7):2566-74. doi: 10.1016/j.bmc.2010.02.034. Epub 2010 Mar 1.


Human African trypanosomiasis (HAT, commonly known as African sleeping sickness) is categorized as a neglected disease, as it afflicts >50,000 people annually in sub-saharan Africa, and there are few formal programs in the world focused on drug discovery approaches for this disease. In this study, we examined the crude extracts of two fungal strains (Aspergillus fumigatus and Nectria inventa) isolated from deep water sediment which provided >99% growth inhibition at 1microg/mL of Trypanosoma brucei, the causative parasite of HAT. A collection of fifteen natural products was supplemented with six semi-synthetic derivatives and one commercially available compound. Twelve of the compounds, each containing a diketopiperazine core, showed excellent activity against T. brucei (IC(50)=0.002-40microM), with selectivity over mammalian cells as great as 20-fold. The trypanocidal diketopiperazines were also tested against two cysteine protease targets Rhodesain and TbCatB, where five compounds showed inhibition activity at concentrations less than 20microM. A preliminary activity pattern is described and analyzed.

Publication types

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

MeSH terms

  • Acetylation
  • Animals
  • Aspergillus fumigatus / chemistry
  • Cysteine Endopeptidases / chemistry
  • Cysteine Proteinase Inhibitors / pharmacology
  • Diketopiperazines / chemistry
  • Diketopiperazines / isolation & purification*
  • Diketopiperazines / pharmacology*
  • Drug Evaluation, Preclinical
  • Fungi / chemistry*
  • Geologic Sediments / chemistry
  • Humans
  • Indicators and Reagents
  • Jurkat Cells
  • Magnetic Resonance Spectroscopy
  • Methylation
  • Piperazines / chemistry
  • Spiro Compounds / chemistry
  • Structure-Activity Relationship
  • Trypanocidal Agents / chemistry
  • Trypanocidal Agents / isolation & purification*
  • Trypanocidal Agents / pharmacology*
  • Trypanosoma brucei brucei / drug effects


  • Cysteine Proteinase Inhibitors
  • Diketopiperazines
  • Indicators and Reagents
  • Piperazines
  • Spiro Compounds
  • Trypanocidal Agents
  • spirotryprostatin A
  • Cysteine Endopeptidases
  • TbcatB protein, Trypanosoma brucei
  • rhodesain