Application of chemically induced dynamic nuclear polarization to the nitration of N-acetyltyrosine and to some reactions of peroxynitrite

By the observation of chemically induced dynamic nuclear polarization in N-15 NMR spectroscopy it has been shown that nitration of N-acetyltyrosine, even render acidic conditions, is largely a radical process. In the alkaline reaction of tyrosine with peroxynitrite the main products are nitrite and nitrate, both produced by a radical pathway, and tyrosine nitration is a minor reaction. It is suggested that tyrosine catalyzes the production of NOS and HO. from peroxgnitrite. (C) 2000 Academic Press.