Inhibitor of thioredoxin reductase (TrxR) (IC50 = 20 nM; Ki = 4 nM for the NADPH-reduced form of human cytosolic TrxR). Thought to induce the mitochondrial permeability transition via inhibition of mitochondrial TrxR. Also exhibits anti-inflammatory and immunosuppressive activities; inhibits 5-lipoxygenase at high concentrations and stimulates LTA hydrolase at low concentrations. MW (observed): 678.48.