NW-G12, a Novel Nonchlorinated Cyclohexapeptide from Streptomyces alboflavus 313

In our continuous investigation of metabolites of Streptomyces alboflavus 313, NW-G12 (1), a novel nonchlorinated analogue of NW-G01, was obtained as a trace constituent in the weak polarity part and a known desertomycin A (2) was also isolated from the fermentation broth in the strong polarity part. The structures of compounds 1 and 2 were established by comprehensive analysis of 1D and 2D NMR spectral data. Moreover, compounds 1 and 2 showed strong antibacterial activities against Bacillus cereus, Staphylococcus aureus, and Bacillus subtilis, with MICs of less than 10 mu g/mL, but both show no antibacterial activities against two gram-negative bacteria.