ABSTRACT
Objective: To identify the cytotoxic natural products from the deep-sea derived Ochrobactrum sp. OUCMDZ-2164. Methods: The isolations and purifications of compounds were performed by means of column chromatography over silica gel and Sephadex LH-20 as well as HPLC. Their structures were elucidated through the analysis of UV, IR, MS, NMR and ECD spectra. The cytotoxicities against MCF-7, A549 and K562 cells were evaluated by MTT and CCK-8 methods. Results: From the fermentation broth of Ochrobactrum sp. OUCMDZ-2164, we isolated and identified four compounds (1-4). Compound 1 was identified as a new ansamycin and named trienomycin J, and the structures of 1-4 were identified as 3-O-demethyltrienomycinol, flazin, flazin-3- carboxylic acid and thymine, respectively. Compound 1 showed cytotoxic effect on the MCF-7 cells with 61.5% inhibition rate at 10 μmol/L. Conclusion: Compound 1 was a new ansamycin named trienomycin J, with cytotoxic activity against human breast cancer cells (MCF-7).