Deacetylravidomycin is a microbial metabolite that has been found in Streptomyces and has light-dependent antibiotic and anticancer activities. It is active against Gram-positive bacteria, including B. subtilis, S. aureus, S. epidermidis, and E. faecalis (MICs = 0.78-1.56 and<0.006-0.049 μg/ml in the absence and presence of fluorescent light, respectively). Deacetylravidomycin also reduces colony formation by human colon cancer cells in a clonogenic assay in a light-dependent manner.