A New Polyketide Antibiotic from the Marine Bacterium Streptomyces sp. PGC 32

A new aromatic polyketide compound, arabomycin (1), along with three known metabolites (2–4), was isolated from the culture broth of the marine bacterium Streptomyces sp. PGC 32. The structure of the new compound was established through 1D and 2D NMR analyses and high-resolution mass spectrometry, and the known compounds were elucidated on the basis of 1H and 13C NMR information in comparison with literature values. Arabomycin (1) was found to have potential antibacterial action against the Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus, and Gram-negative bacteria Escherichia coli and Enterobacter sp.