Viridamides A and B, lipodepsipeptides with antiprotozoal activity from the marine cyanobacterium Oscillatoria nigro-viridis

J Nat Prod. 2008 Sep;71(9):1544-50. doi: 10.1021/np800110e. Epub 2008 Aug 21.


Parallel chemical and phylogenetic investigation of a marine cyanobacterium from Panama led to the isolation of two new PKS-NRPS-derived compounds, viridamides A and B. Their structures were determined by NMR and mass spectroscopic methods, and the absolute configurations assigned by Marfey's method and chiral HPLC analysis. In addition to six standard, N-methylated amino and hydroxy acids, these metabolites contained the structurally novel 5-methoxydec-9-ynoic acid moiety and an unusual proline methyl ester terminus. Morphologically, this cyanobacterium was identified as Oscillatoria nigro-viridis, and its 16S rDNA sequence is reported here for the first time. Phylogenetic analysis of these sequence data has identified O. nigro-viridis strain OSC3L to be closely related to two other marine cyanobacterial genera, Trichodesmium and Blennothrix. Viridamide A showed antitrypanosomal activity with an IC50 of 1.1 microM and antileishmanial activity with an IC50 of 1.5 microM.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antiprotozoal Agents / chemistry
  • Antiprotozoal Agents / isolation & purification*
  • Antiprotozoal Agents / pharmacology*
  • Cyanobacteria / chemistry*
  • Depsipeptides / chemistry
  • Depsipeptides / isolation & purification*
  • Depsipeptides / pharmacology*
  • Leishmania mexicana / drug effects
  • Marine Biology
  • Molecular Structure
  • Panama
  • Plasmodium falciparum / drug effects
  • Trypanosoma cruzi / drug effects


  • Antiprotozoal Agents
  • Depsipeptides
  • viridamide A
  • viridamide B