Lyngbyaureidamides A and B, two anabaenopeptins from the cultured freshwater cyanobacterium Lyngbya sp (SAG 36.91)

Two anabaenopeptin-type peptides, lyngbyaureidamides A and B, together with two previously reported peptides lyngbyazothrins C and D, were isolated from the cultured freshwater cyanobacterium Lyngbya sp. (SAG 36.91). Their structures were determined by spectroscopic and chemical methods. Lyngbyazothrins C and D were also able to inhibit the 20S proteasome with IC50 values of 7.1 mu M and 19.2 mu M, respectively, while lyngbyaureidamides A and B were not active at 501 mu M. (C) 2011 Elsevier Ltd. All rights reserved.