Oxidation of non-phenolic substrates with the laccase/N-hydroxyacetanilide system: Structure of the key intermediate from the mediator and mechanistic insight
Abstract
We have investigated the reactivity and mechanistic features in the oxidation of non-phenolic substrates by the enzyme laccase under mediation by N–O˙ reactive intermediate of the mediator, formed in a preliminary oxidative interaction with the enzyme, seems the more viable
N–O˙ intermediate of NHA. The occurrence of an alternative ionic route through the oxoammonium ion (
N
O+) of mediator NHA is ruled out by experimental evidence acquired through an Hammett structure/reactivity correlation in the oxidation of substituted
N
O+ species of NHA, being a one-electron oxidant of moderate strength, could in principle even be responsible for an alternative electron-transfer route of