Dimeric Tetracenomycin Derivatives from a Taklamakan Desert-Derived sp. HDN154193.

Bitetracenomycin A () and its diastereomers [(±)-bitetracenomycin B, (±)-] were discovered from the cultures of sp. HDN154193. Compounds and (±)- were the first tetracenomycin dimers obtained from a natural source with sp methine protons at the bridge positions (C-12/12'), which also exhibited broad-spectrum antibacterial activity. The racemate (±)- was semisynthesized and separated into enantiomers (+)- and (-)-, and the absolute configurations were determined by specific rotation and ECD data. These metabolites exhibited potent antibacterial activity especially against drug-resistant strains (MRSA and MRCNS) with MIC values ranging from 1.0 to 1.9 μg/mL.