β-Rubromycin was first isolated from a Streptomyces sp. by Brockmann and colleagues in 1969, with its structure revised in 2000. β-Rubromycin has marked activity against B. subtilis, S. aureus and E. coli, as well as other Gram positive organisms. β-Rubromycin demonstrates 50% inhibition of growth (GI50) of stomach adenocarcinoma HM02, colon carcinoma Kato III and breast adenocarcinoma MCF7 cell lines at concentrations of 0.5, 0.84 and <1.0 µM, respectively. β-Rubromycin has weak activity against HIV reverse transcriptase. The rubromycins were reviewed by Brasholz et al. in 2007.