Polymer-assisted biocatalysis: Unprecedented enzymatic oxidation of fullerene in aqueous medium

Enzymatic complexes, constructed by linear-dendritic copolymers and laccase, are used for the unprecedented one-pot biotransformation of fullerene (C60) into epoxide- and hydroxyl-derivatives under mild and environmentally friendly reaction conditions (45 °C and aqueous medium). The reaction is catalyzed by mediator pairs - N-hydroxy-5-norbornene-2,3-dicarboxylic acid imide/1-Hydroxybenzotriazole or 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)/1-Hydroxybenzotriazole used in equimolar amounts. After 24 and 48 h, the biotransformation products C60On, C60(OH)n, C60(H)n(OH)n, and/or C60On(H)m(OH)m range between 50 and 78%, respectively. Their structure is revealed by FTIR, NMR, and mass-spectrometry. The mechanism of the process is discussed and elucidated. The reaction procedure allows the repeated usage of the enzyme/linear-dendritic complex, which retains its catalytic activity after several cycles. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012