Tolaasins A--E, five new lipodepsipeptides produced by Pseudomonas tolaasii

J Nat Prod. 2004 May;67(5):811-6. doi: 10.1021/np0303557.


Pseudomonas tolaasii, the causal organism of brown blotch disease of Agaricus bisporus and of the yellowing of Pleurotus ostreatus, was shown to produce in culture tolaasin I (1), tolaasin II (2), and five other minor metabolites, tolaasins A, B, C, D, and E (3-7). These compounds were demonstrated to be important in the development of the disease symptoms. This paper reports on the structural elucidation, based essentially on NMR studies and MS spectra, and biological activity of the above lipodepsipeptides (3-7). All the above analogues showed differences in the peptide moiety, as observed in other lipodepsipeptides of bacterial origin, and maintained the beta-hydroxyoctanoyl phi chain at the N-terminus, except tolaasin A, in which the acyl moiety was a gamma-carboxybutanoyl phi moiety. Among the target microorganisms used (fungi, yeast, and bacteria) the Gram-positive bacteria were the most sensitive, although the antimicrobial activity appeared to be correlated to the structural modification in the different analogues. The structure-activity relationships of these toxins are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agaricus*
  • Bacillus megaterium / drug effects
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / isolation & purification*
  • Bacterial Proteins / pharmacology
  • Bacterial Toxins / chemistry
  • Bacterial Toxins / isolation & purification*
  • Bacterial Toxins / pharmacology
  • Erwinia / drug effects
  • Escherichia coli / drug effects
  • Microbial Sensitivity Tests
  • Nuclear Magnetic Resonance, Biomolecular
  • Plant Diseases
  • Pseudomonas / chemistry*
  • Rhizoctonia / drug effects
  • Rhodotorula / drug effects
  • Structure-Activity Relationship


  • Bacterial Proteins
  • Bacterial Toxins