Isolation, structure elucidation, and antibacterial activity of methiosetin, a tetramic acid from a tropical sooty mold (Capnodium sp.)

J Nat Prod. 2012 Mar 23;75(3):420-4. doi: 10.1021/np200857y. Epub 2012 Jan 30.


Drug-resistant bacteria continue to make many existing antibiotic classes ineffective. In order to avoid a future epidemic from drug-resistant bacterial infections, new antibiotics with new modes of action are needed. In an antibiotic screening program for new drug leads with new modes of action using antisense Staphylococcus aureus Fitness Test screening, we discovered a new tetramic acid, methiosetin, from a tropical sooty mold, Capnodium sp. The fungus also produced epicorazine A, a known antibiotic. The structure and relative configuration of methiosetin was elucidated by 2D NMR and ESIMS techniques. Methiosetin and epicorazine A showed weak to modest antibacterial activity against S. aureus and Haemophilus influenzae. The isolation, structure elucidation, and antibacterial activity of both compounds are described.

MeSH terms

  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / isolation & purification*
  • Anti-Bacterial Agents / pharmacology
  • Ascomycota / chemistry*
  • Guatemala
  • Haemophilus influenzae / drug effects
  • Methicillin-Resistant Staphylococcus aureus / drug effects
  • Microbial Sensitivity Tests
  • Molecular Structure
  • Piperazines / isolation & purification
  • Piperazines / pharmacology
  • Pyrrolidinones / chemistry
  • Pyrrolidinones / isolation & purification*
  • Pyrrolidinones / pharmacology*


  • Anti-Bacterial Agents
  • Piperazines
  • Pyrrolidinones
  • methiosetin
  • tetramic acid
  • epicorazine A