Fungal metabolites. XIX. Structural elucidation of channel-forming peptides, trichorovins-I-XIV, from the fungus Trichoderma viride.

Trichorovins (TV)-I-XIV are new antibiotic peptides obtained from conidia of the fungus Trichoderma viride. The peptide mixture of TVs was repeatedly fractionated by preparative HPLC until individual TVs showed a single peak on their analytical HPLC chromatograms. Nevertheless, FAB-MS or NMR indicated that each of TVs-I-XIV was composed of at least two components. We attempted to elucidate their structures within the fractions by electrospray ionization (ESI)-MS, FAB-MS, FAB-MS/MS and NMR. TVs generally have molecular weights of approximately 1100-1200 Da, and are characterized by an acetylated N-terminus, the presence of an aminoalcohol, e.g. leucinol, isoleucinol or valinol, at the C-terminus, and eleven residues including three alpha-aminoisobutyric acids in the molecule. Thus, it was determined that TVs belong to the class of peptaibols.