Isolation of a new antibiotic 333-25, related to antibiotic EM 49. (Studies on antibiotics from the genus Bacillus. XI).

A new antibiotic, 333-25, active against Gram-positive and Gram-negative bacteria, was isolated from the culture broth of Bacillus circulans 333-25. The antibiotic is a basic acylpeptide containing 2,4-diaminobutyric acid (5), leucine (2), phenylalanine (1) and a fatty acid. It is closely related to antibiotic EM 49, but can be differentiated by chromatographic behaviour.