3-Benzylmenadiones were obtained in good yield by using a blue-light-induced photoredox process the presence of Fe(III), oxygen, and γ-terpinene acting as hydrogen-atom transfer agent. This methodology is compatible with wide variety diversely substituted 1,4-naphthoquinones well various cheap, readily available benzyl bromides excellent functional group tolerance. The benzylation mechanism was...

Tyrosinase exhibits catalytic activity for the ortho-hydroxylation of monophenols to diphenols as well as their subsequent oxidation to quinones. Owing to polymerization of these quinones, brown-coloured high-molecular-weight compounds called melanins are generated. The latent precursor form of polyphenol oxidase 4, one of the six tyrosinase isoforms from Agaricus bisporus, was purified to homo...

Many xenobiotics, including naturally occurring compounds, drugs, and environmental agents, are metabolized both in vivo and in vitro to free-radical intermediates. The one-electron reduction of nitroaromatic compounds, quinones, and a wide variety of other chemicals is catalyzed enzymatically by a number of reductases and dehydrogenases. Structure-activity studies have shown that the cytotoxic...