Hydroxylation of naphthalene by aromatic peroxygenase from Agrocybe aegerita proceeds via oxygen transfer from H2O2 and intermediary epoxidation
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Agrocybe aegerita peroxidase/peroxygenase (AaP) is an extracellular fungal biocatalyst that selectively hydroxylates the aromatic ring of naphthalene. Under alkaline conditions, the reaction proceeds via the formation of an intermediary product with a molecular mass of 144 and a characteristic UV absorption spectrum (A max 210, 267, and 303 nm). The compound was semistable at pH 9 but spontaneously hydrolyzed under acidic conditions (pH <7) into 1-naphthol as major product and traces of 2-naphthol. Based on these findings and literature data, we propose naphthalene 1,2-oxide as the primary product of AaP-catalyzed oxygenation of naphthalene. Using 18O-labeled hydrogen peroxide, the origin of the oxygen atom transferred to naphthalene was proved to be the peroxide that acts both as oxidant (primary electron acceptor) and oxygen source.
KeywordsPeroxidase Oxygenation Hydroxylation P450 Naphthol
The authors would like to thank the following institutions and organizations for financial support: European Union (integrated project BIORENEW), the German Ministry of Education and Research (BMBF, project 0313433D), and the German Environmental Foundation (DBU, project 13225-32).
- Boyd DR, Sharma ND, Agarwal SK, Balani K, Dunlop R, Gadaginamath GS, O'Kane GA, Jennings WB, Yagi H, Jerina DM (1987) Preparation of oxepines during direct chemical synthesis and facile oxygen walk reactions of arene oxides: theoretical predictions and experimental evidence. Chem Soc Chem Commun 1987:1633–1635CrossRefGoogle Scholar