S-Methyl-L thiocitrulline Dihydrochloride is a potent cell-permeable inhibitor of neuronal nitric oxide synthase (IC50 = 300 nM), and a fairly potent inhibitor of endothelial nitric oxide synthase (IC50 = 5.4 μM). Has been shown to provide neuroprotection in mice, thought to be accomplished by blocking NO generation, which could otherwise combine with free radicals producing tissue damaging peroxynitrites.
