Figure 25.

Oxidative transformations of dehydro NADA. Dehydro NADA upon oxidation produces directly a highly reactive quinone methide, which crosslinks proteins and chitin (not shown in figure). It also reacts with the starting compound forming a benzodioxan dimer. The accumulated dimer reacts with another molecule of quinone methide forming trimer. Oligomers up to hexamer have been characterized. One-electron oxidation of dehydro NADA generates the semiquinone, which is in equilibrium with the quinone methide radical. Radical coupling in this case produces the same dimer but not the oligomers.