Isolation and structure determination of a new lantibiotic cinnamycin B from Actinomadura atramentaria based on genome mining.

New lantibiotic cinnamycin B was isolated from the extract of Actinomadura atramentaria NBRC 14695(T), based on genome mining and chemical investigation. The partial structure of cinnamycin B was established by 2D NMR experiments, which indicated that cinnamycin B had same methyl lanthionine bridging pattern with cinnamycin. The reduction with NaBH4-NiCl2 afforded the reduced cinnamycin B, and MS/MS experiment indicated the presence of hydroxy asparatic acid in the molecule. Cinnamycin B showed an antibacterial activity against Streptomyces antibioticus with dosage of 5 μg (0.5μL, 10 mg/mL solution) at spot-on-lawn testing method. The gene cluster of cinnamycin B on the genome of A. atramentaria was identified and discussed in comparison with that of cinnamycin.