A novel synthesis of bioactive catechols by Layer-by-Layer immobilized Tyrosinase in organic solvent medium

Commercial and extracted mushroom tyrosinase was either supported on Eupergit ® C250L and protected by coating with oppositely charged polyelectrolytes by means of the layer-by-layer (LbL) technique. The novel biocatalysts were characterized on their kinetic parameters (K m , V max , V max /K m ) in both organic and aqueous media. This analysis showed that tyrosinase was more reactive in organic solvent than in buffer. Heterogeneous tyrosinase systems were applied for the oxidation of a large panel of phenol derivatives to corresponding catechols. A different reactivity of the enzyme was found in relation with the structure of the substrate. However biocatalysts showed good catalytic activities to yield catechols, better in organic medium than in aqueous ones. The activity was retained for successive runs. Since catechols are biologically active compounds difficult to synthesize by traditional chemical procedure under environmental friendly conditions, the use of immobilized tyrosinase open a novel synthetic alternative for this interesting family of substances.