Isolation and characterization of katanosins A and B.

Two peptide antibiotics katanosins A and B were isolated from the culture broth of a strain related to the genus Cytophaga. These antibiotics are basic peptides soluble in aqueous alcohols. The molecular formulae C57H95N15O17 for A and C58H97N15O17 for B were indicated. The constituent amino acids of katanosin A are suggested to be Thr (1), Ser (1), Val (1), Leu (3), Arg (1) and three unusual amino acids. In katanosin B, the Val residue is replaced by Ile. Katanosins A and B are active against Gram-positive bacteria in vitro and in vivo.