Two types of novel peptides, cyclic peptides, nodulapeptins A (1) and B (2) and linear peptides, spumigins A similar to C (3 similar to 6), were isolated together with nodularin from toxic Nodularia spumigena AV1. Their structures were determined by 2D-NMR techniques, the advanced Marfey's method and MS/MS experiments. (C) 1997 Elsevier Science Ltd.