An investigation of enzymatic kinetic resolution of racemic clopidogrel

This paper presents a biocatalysis based approach for asymmetric hydrolysis of Clopidogrel, one of the most effective antiplatelet aggregators. Instead of the conventional "wet lab" screening method, we used an advanced chemical information retrieval tool, Scifinder®, to find suitable enzyme candidate(s) for the asymmetric hydrolysis. Scifinder® search for reactions similar to the target reaction retrieved three potential hits: horse liver esterase, chymotrypsin and Candida rugosa lipase. Among the three, horse liver esterase was experimentally found to hydrolyse the correct isomer (R) of the racemic clopidogrel. Investigation of the effect of different water miscible co-solvents showed DMSO to provide the highest enantiomeric excess (ee) value of 20% at 43% conversion of the racemic ester, while a dicyanamide based ionic liquid as a co-solvent showed 12% ee. This article demonstrates the potential of the chemical databases as a possible rapid, resource-efficient tool to find an appropriate selective biocatalyst.