Grassypeptolides F and G, Cyanobacterial Peptides from Lyngbya majuscula

Grassypeptolides F (1) and G (2), bis-thiazoline-containing cyclic depsipeptides with a rare beta-amino acid, extensive N-methylation, and a large number of D-amino acids, are reported from an extract of the Palauan cyanobacterium Lyngbya majuscula. Both 1 and 2 were found to have moderate inhibitory activity against the transcription factor AP-1 (IC(50) = 5.2 and 6.0 mu M, respectively).