Production of a chiral alcohol, 1-(3,4-dihydroxyphenyl) ethanol, by mushroom tyrosinase

1-(3,4-Dihydroxyphenyl) ethanol was produced biocatalytically for the first time using mushroom tyrosinase. 4-Ethylphenol at 1 mM was consumed over 12 min giving 0. 23 mM 4-ethylcatechol and 0. 36 mM (R/S)-1-(3,4-dihydroxyphenyl) ethanol (ee 0. 5 %). Mushroom tyrosinase consumed 4-ethylphenol at 6. 7 μmol min^-1 mg protein^-1 while the rates of formation of 4-ethylcatechol and 1-(3,4-dihydroxyphenyl) ethanol were 1. 1 and 1. 9 μmol min^-1 mg protein^-1. Addition of the ascorbic acid, as a reducing agent to biotransformation reactions, increased 4-ethylcatechol formation by 340 %. However, accumulation of 1-(3,4-dihydroxyphenyl) ethanol was not observed in the presence of ascorbic acid. While the 1-(3,4-dihydroxyphenyl) ethanol was racemic, it is the first chiral product produced by tyrosinase starting from a non-chiral substrate.