Eugenol, a methoxyphenol found in various essential oils such as clove, bay laurel, cinnamon leaf, and rosemary, appears to be a particulary effective peorxynitrites scavenger (the methyl group binds to peroxynitrites and the phenol group converts it into water and a nitrogen dioxide anion).
FORBES: The Lessons Of Failure: What We Can Learn From Bapineuzumab's Blowup