Purity >95%. Oligomycins are macrolides created by Streptomyces species that can be toxic to other organisms through their ability to inhibit mitochondrial membrane-bound ATP synthases. The mitochondrial F1 FO ATP synthase can switch to an ATP hydrolase during ischemia, so that, under these conditions, inhibition by oligomycins will reduce ATP depletion rather than block ATP synthesis. Oligomycin complex is a mixture of oligomycins A , B , and C. Oligomycin A is a selective inhibitor of mitochondrial F1 FO -ATP synthase that induces apoptosis in a variety of cell types (average GI50 = 270 nM). Oligomycin B is a nonselective inhibitor of ATP synthases. Oligomycin B (1-10 μM) can reduce the rate of ATP depletion in myocardial ischemia and decrease calcium-induced calcium release oscillation frequency of rat sensory neurons.