K-582, a new peptide antibiotic. I

A new basic peptide antibiotic designated as K-582 was isolated, purified and characterized. When K-582 was applied to a column of Al2O3 or Biol-Gel P-2 or CM Sephadex, two major peaks which were named Fraction I (K-582 A) and Fraction II (K-582 B) were obtained. The nitrogen content, the behavior in color reaction, the absorption bands of amide linkages in the infrared absorption spectrum, 1H NMR spectrum and C-13 NMR spectrum indicated the peptide nature of K-582 A and K-582 B. K-582 was effective against yeasts, but inactive against other Gram-positive bacteria, Gram-negative bacteria and Mycobacterium. The toxicity was low in mice.