Oligomycin B is a minor analog of a class of macrocyclic lactones isolated from selected strains of Streptomyces spp. It is a non-selective inhibitor of mitochondrial F1F0 ATP synthase in eukaryotes. Oligomycins exhibit apoptotic cytotoxicity and mitochondrial toxicity. It can induce apoptosis in a variety of cell types. It is practically free of homologs. Oligomycin B has the base structure of Oligomycin A but the spirocyclic ring with the 2-hydroxypropyl has been substituted by an oxo group._x000D_ Oligomycin is a macrolide antibiotic complex from Streptomyces. It is an inhibitor of mitochondrial F1F0 ATP synthase. The Oligomycin complex was first reported in 1954, from a strain of Streptomyces diastatochromogenes from soil highly active against fungi. The Oligomycin class includes the analogs/isomers A through G. Different isomers are highly specific for the disruption of mitochondrial metabolism. Oligomycin can be used to study the mechanistic aspects of ATP formation in tumor cell biology and apoptosis._x000D_ Oligomycin B is soluble in ethanol, methanol, DMSO and DMF. Practically insoluble in water.