Isolation, structure, and antibacterial activity of phaeosphenone from a Phaeosphaeria sp. discovered by antisense strategy

J Nat Prod. 2008 Jul;71(7):1304-7. doi: 10.1021/np8001833. Epub 2008 Jun 21.


Ribosomal protein S4 (RPSD), a part of the ribosomal small subunit, is one of the proteins that is a part of the ribosomal machinery and is a potential new target for the discovery of antibacterial agents. Continued screening of microbial extracts using antisense-sensitized rpsD Staphylococcus aureus strain led to the isolation of a new dimeric compound, phaeosphenone (2). Compound 2 showed broad-spectrum antibacterial activity against Gram-positive bacteria, exhibiting MIC values ranging from 8 to 64 microg/mL. Phaeosphenone showed the highest sensitivity for Streptococcus pneumoniae (8 microg/mL) and inhibited the growth of Candida albicans with an MIC of 8 microg/mL. Phaeosphenone showed a modest selectivity for the inhibition of RNA synthesis over DNA and protein synthesis in S. aureus.

MeSH terms

  • Anthraquinones / chemistry
  • Anthraquinones / isolation & purification*
  • Anthraquinones / pharmacology*
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / isolation & purification*
  • Anti-Bacterial Agents / pharmacology*
  • Antisense Elements (Genetics)
  • Ascomycota / chemistry*
  • Candida albicans / drug effects
  • Gram-Positive Bacteria / drug effects
  • Microbial Sensitivity Tests
  • Molecular Sequence Data
  • Molecular Structure
  • Nucleic Acid Synthesis Inhibitors / chemistry
  • Nucleic Acid Synthesis Inhibitors / isolation & purification
  • Nucleic Acid Synthesis Inhibitors / pharmacology
  • Ribosomal Proteins / drug effects*
  • Staphylococcus aureus / drug effects
  • Streptococcus pneumoniae / drug effects


  • Anthraquinones
  • Anti-Bacterial Agents
  • Antisense Elements (Genetics)
  • Nucleic Acid Synthesis Inhibitors
  • Ribosomal Proteins
  • phaeosphenone
  • ribosomal protein S4

Associated data

  • GENBANK/AF181708
  • GENBANK/AF196988
  • GENBANK/AF817684