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Paracelsin, a hemolytic and membrane active polypeptide antibiotic of the peptaibol class which is excreted by the mold Trichderma reesei, was obtained by a simplified and isolation procedure utilziing hydrophobic adsorber resin. Investigation byC nuclear magnetic resonance spectroscopy and circular dichroism revealed considerable helical portions in solution, and the very recently accomplished sequence determination of paracelsin allows the discussion of the results with regard to the closely related analogues, alamethicin and suzukacillin. A selective cleavage of the peptide was achieved by careful treatment with various acids, and a buffer of pH 8.25 and of high ionic strength made possible the quantitative determination of the C-terminal phenylalaninol released by means of ion-exchange chromatography. The significance of the production of paracelsin and related mycotoxins of the peptaibol class, exhibiting various kinds of biological activity, is discussed with respect to the extensive effort being made towards biotechnological applications of species, strains and cellulolytically highly active mutants of the fungus Trichoderma. [ABSTRACT FROM AUTHOR]

A peptide antibiotic has been isolated from Trichoderma reesei QM 9414. Although crystalline and unifiorm in TLC, this antibiotic could be resolved by HPLC into 3 sequence analoques. The close relationships to alamethicin was proved by chemical and spectroscopic methods, and the formation of ion-conducting prores in lipid bilayers. [ABSTRACT FROM AUTHOR]