Two new macrolide derivatives, madangolide (2) and laingolide A (3), have b
een isolated from the cyanobacterium Lyngbya bouillonii, collected in Papua
New Guinea. Their structures (without stereochemistry) have been establish
ed by detailed high-field 1D and 2D NMR studies and, in the case of 3, by c
omparison with the spectroscopic data of laingolide (1), previously isolate
d from the same organism.