Indanomycin-related antibiotics from marine Streptomyces antibioticus PTZ0016.

Four indanomycin-related antibiotics 2-5 were isolated from the cultured broth of marine Streptomyces antibioticus strain PTZ0016. Their structures were characterised as 16-deethylindanomycin (2), iso-16-deethylindanomycin (3), 16-deethylindanomycin methyl ester (4) and iso-16-deethylindanomycin methyl ester (5) on the basis of NMR, HR-ESI-MS and CD evidences. Compounds 3-5 are new additions to the class of indanomycin antibiotics. All isolated compounds showed in vitro activity against Staphylococcus aureus with minimal inhibitory concentration at 4.0-8.0 μg/ml.