Autoxidation of 4-methylcatechol: a model for the study of the biosynthesis of copper amine oxidases quinonoid cofactor

RINALDI, ANDREA;PORCU MC;CURRELI, NICOLETTA;RESCIGNO, ANTONIO;FINAZZI AGRÒ A;PEDERSEN JZ;RINALDI A;SANJUST, ENRICO

1995-01-01

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Abstract

The autoxidation of 4-methylcatechol under quasi-physiological conditions, leading to 2-hyddroxy-5-1,4-benzoquinone, was investigated. The effects of pH and metal ions were examined. An electrophilic attack of dioxygen to the 4-methylcatechol monoanion to form a transient peroxo species is proposed. It was concluded that such a non-enzymic conversion is likely for this model compound and for its physiological counterpart, a specific tyrosyl residue incorporated in the protein chain al the active site of copper amine oxidases.