Conglobatin B is a bacterial metabolite that has been found in Streptomyces MST-91080 and has anticancer activity.1 It is cytotoxic to NS-1 mouse myeloma cells (IC50 = 0.084 µg/ml) but not NFF human fibroblasts (IC50 = >100 µg/ml).WARNING This product is not for human or veterinary use.