In a previous paper1) we reported the new peptaibol-type antibiotic ampullosporin A (1, Fig. 1), production by the fungal strain of Sepedonium ampullosporum, structure elucidation, and biological activities. Ampullosporin A (1) was discovered as an inducer of pigment formation by the fungal strain of Phoma destructiva. Moreover, strong neuroleptic activity was established for 1 in mice and rats as test animals1'2). In order to disclose structure-activity relationships amongst the naturally occurring homologues and isomers of ampullosporin A we investigated the metabolite spectrum of the producer strain Sepedonium ampullosporum by HPLC and mass spectrometry (LC-MS, ESI-CID-MS/MS, ESI-CID-MSn). These investigations unraveled the presence of minor components such as ampullosporins B (2), C (3), D (4) and E, amounting to 1-5% of the produced ampullosporin A (1). Component E was shown to be a mixture of four isomers (E1 (5), E2 (6), E3 (7), E4 (8); Fig. 1). Here we report the isolation, structure elucidation and biological activities of compounds 2-8.