Oxidation of isoeugenol and coniferyl alcohol catalyzed by laccases isolated from Rhus vernicifera Stokes and Pycnoporus coccineus

Laccases isolated from Rhus vernicifera Stokes (tree) and Pycnoporus coccineus (fungus) catalyzed the oxidation of isoeugenol (1) and coniferyl alcohol (5) in acetone-water (1:1, v/v). These oxidations follow a first order rate law. In general, the rates of Pycnoporus laccase-catalyzed oxidation of 1 and 5 are approximately three and seven times faster than the corresponding rates of Rhus laccase-catdyzed oxidation, respectively. Thus, synthesis for 2-(4-hydroxyphenyl)coumaran type compounds, such as dehydrodiconiferyl alcohol, can be accomplished by Rhus laccase-catalyzed dehydrogenative polymerization of the corresponding 1-(4-hydroxyphenyl)-1-propene derivatives. The reaction proceeds under very mild reaction conditions. The resulting reaction mixtures are chromatographed on a silica gel column to isolate the products in approximately 30-40% yield. (C) 2000 Elsevier Science B.V. All rights reserved.