Cephaibols, new peptaibol antibiotics with anthelmintic properties from Acremonium tubakii DSM 12774

Two groups of new peptaibol-type antibiotics termed cephaibols have been is olated from the fungus: Acremonium tubakii, DSM 12774. These 16- or 17-unit straight-chain peptides, whose structures were characterized by amino acid analyses, 2-D NMR experiments, and by mass spectrometric sequencing, have a high content of the unusual amino acids aminoisobutyric acid and isovalin e. The principal constituent of the novel peptaibol mixture is cephaibol A, which is formed in abundance in cultures of the wild strain. The striking biological property of cephaibol A is its pronounced anthelmintic action an d activity against ectoparasites.