Antraformin, a new inhibitor of Bacillus subtilis transformation

A convenient method was worked out which discriminates between inhibitory activity of compounds against Bacillus subtilis transformation and their antibacterial or growth inhibition activity. By this assay system, several drugs and antibiotics were tested and some of them were found to be more inhibitory to transformation than to bacterial growth. This method was further applied to look for specific inhibitors among culture broths of Streptomyces, and during this screening program, Streptomyces sp. 7725-CC1 was found to produce a specific inhibitor of B. subtilis transformation. The active substance was purified and named antraformin after its specific action. The molecular weight was suggested to be 279 (C14H21N3O2) for the compound by high resolution mass spectrometry.