Besarhanamides A and B from the marine cyanobacterium Lyngbya majuscula

Besarhanamides A(1) and B(2) are fatty acid amides purified from the marine cyanobacterium, Lyngbya majuscula, collected from Pulau Hantu, Singapore. The structure determination of these secondary metabolites was carried out using extensive 2D NMR spectral data as well as chemical manipulations including the Marfey's method. In addition, besarhanamide A exhibited moderate toxicity with LD(50) at 13 mu M in the brine shrimp toxicity bioassay. (C) 2008 Elsevier Ltd. All rights reserved.