hemi-Oxanthromicin is the monomer of (±)-oxanthromicin, first isolated from a soil-derived Streptomyces sp. by Capon and co-workers in 2014. Unlike its co-metabolites, oxanthromicin and spiro-oxanthromicin, hemi-oxanthromicin does not inhibit mislocalisation of the oncogenic mutant K-Ras from the plasma membrane of intact Madin-Darby canine kidney (MDCK) cells. hemi-Oxanthromicin was largely inactive in assays for antibacterial, antiviral, antimycobacterial and phytopathogenic activity (MIC >50 µg/mL). hemi-Oxanthromicin shows minimal cytotoxicity.