Isolation of cepafungins I, II and III from Pseudomonas species.

New acylpeptide antibiotics named cepafungins I, II and III were isolated from the culture broth of a strain identified as Pseudomonas sp. These antibiotics are neutral substances, soluble in aqueous alcohols and dimethyl sulfoxide, and show UV maxima at 260.5 nm. The IR spectra indicated these to be peptides. Molecular formulas C28H46N4O6, C27H44N4O6 and C26H42N4O6 for cepafungins I, II and III were indicated by elemental analysis and SI-MS. Cepafungins exhibited inhibitory activity against yeast and fungi, and antitumor activity against P388 leukemia in mice.