A study of the reaction of different phenol substrates with nitric oxide and peroxynitrite

Article abstract of DOI:10.1016/S0040-4020(99)00877-7

The reactivity of different phenol substrates with nitric oxide and peroxynitrite was investigated. In general, nitration is the major reaction with peroxynitrite, while reactions with aqueous solutions of nitric oxide led to mixtures of nitro and nitroso derivatives depending upon the phenol. Nitrosation occurs on phenol substrates bearing a free para- position with respect to the OH group with the exception of 1-naphthol, which afforded a 1:1 mixture of the 2- and the 4-nitroso derivatives. Chromans 7 and 8 showed the highest reactivity with peroxynitrite, which suggests that they can act as efficient scavengers of this toxic intermediate. In both cases the corresponding 5-nitro derivative was the only reaction product detected. Finally, the fact that chroman 8 reacts with nitric oxide to afford the p- quinone derivative 22a in 90% yield suggests that this antioxidant could also be of potential use as specific nitric oxide tracer in biological tissues.