Biphenomycins A and B, novel peptide antibiotics. I. Taxonomy, fermentation, isolation and characterization.

Biphenomycin A, C23H28N4O8, and biphenomycin B, C23H28N4O7, were isolated from the cultured broth of Streptomyces griseorubiginosus No. 43708. The antibiotics are active in vitro and in vivo against bacteria, and are especially potent against Gram-positive bacteria. The acute toxicity of biphenomycin A is very low in mice.