A Laccase-Catalysed Synthesis of Naphthoquinone Bis-Sulfides
Kevin W. Wellington
CSIR Biosciences, Modderfontein , South Africa
Abstract:
Laccases (benzenediol:oxygen oxidoreductase, EC 1.10.3.2) are multi-copper-containing oxidoreductase enzymes that are able to catalyze the oxidation of various low-molecular weight compounds such as phenols and anilines.1-3 The oxidation involves the concomitant reduction of molecular oxygen to water which is the only by-product.1-3 The high stability, selectivity for phenolic substructures, and mild reaction conditions, has made laccases attractive for fine chemical synthesis. In addition, the search for new, efficient and environmentally benign processes has increased interest in these ‘green’ catalysts.
In our current research program on biocatalysis and green chemistry investigations are being conducted to discover novel applications and to develop Green methods of synthesis using laccase. In this work a report is given on the first application of laccases in C-S bond formation for the synthesis of naphthoquinone bis-sulfides from an aromatic or aliphatic thiol and a hydroquinone. The products were synthesised under mild reaction conditions in a vessel open to air in the presence of laccase and a co-solvent. These products may have antibiotic, anticancer, antifungal, anti-allergic, and/or antiviral activity.
References
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2. Rodríguez Couto, S.; Toca Herrera, J. L. Biotechnol. Adv.2006, 24, 500.
