Enzymatic synthesis of catechol-functionalized polyphenols with excellent selectivity and productivity

Polyphenol products have become more and more attractive due to their strong anti-oxidant properties and a great variety of promising pharmacological activities and beneficial effects on human health. In this study, mushroom tyrosinase immobilized as cross-linked enzyme aggregates (CLEAs) was used as the catalyst for ortho-hydroxylation reactions to produce 3,4-dihydroxyphenylacetic acid, piceatannol and 3'-hydroxypterostilbene from 4-hydroxyphenylacetic acid, resveratrol and pterostilbene, respectively, with excellent selectivity and productivity. This is the first report of synthesizing these three polyphenolic compounds with tyrosinase CLEAs as catalyst, and the first study of biocatalytic production of 3'-hydroxypterostilbene. Introducing a deep eutectic solvent (DES) into the tyrosinase CLEA preparation exhibited a positive effect in terms of enhancing the catalytic activity of the immobilized enzyme and also promoting the synthesis of the polyphenol products.