Kimidinomycin, a new antibiotic against Mycobacterium avium complex, produced by Streptomyces sp. KKTA-0263.

During our screening for antibiotics against Mycobacterium avium complex (MAC) with a mass spectrometry network-based indexing approach, a new compound named kimidinomycin was isolated from the culture broth of Streptomyces sp. KKTA-0263 by solvent extraction, HP20 column chromatography, and preparative HPLC. From the structural elucidation, the compound possesses a 38-membered macrolide structure with an N-methylguanidyl group at the terminal side chain. The compound exhibited antimycobacterial activity against M. avium, M. intracellulare, M. smegmatis, and M. bovis BCG with respective MIC values of 12.5, 0.78, 12.5, and 25.0 µg ml-1.