Biotransformation of resveratrol: synthesis of trans-dehydrodimers catalyzed by laccases from Myceliophtora thermophyla and from Trametes pubescens

Laccases from different sources have been used, for the first time, for the selective oxidation of the stilbenic phytoalexin transresveratrol (3,5,4´-trihydroxystilbene, 1a) on a preparative scale. Specifically, the enzymes from Myceliophtora thermophyla and from Trametes pubescens gave the dehydrodimer 2a in 31 and 18% isolated yields, respectively. These results compare favorably with the reported data for the chemically catalyzed dimerization of la (18% yields). The antioxidant properties of 2a have also been investigated.