Immobilization of the Solanum tuberosum epoxide hydrolase and its application in an enantioconvergent process

Abstract

Five supports have been evaluated for the immobilization of the epoxide hydrolase from Solanum tuberosum (StEH) by adsorption. The highest immobilization yield (90–99%) and the maximum EH (epoxide hydrolase) activity (0.6 U g⁻¹ wet support) were obtained by ionic adsorption onto DEAE-cellulose. Although the activity recovered upon immobilization of StEH onto DEAE-cellulose was low, a notable stabilization factor of 6.9 at 65°C was obtained. In addition, the immobilized StEH showed a higher temperature for maximal activity (57°C) and the optimal pH (5.0) was shifted one unit towards the acidic region as compared to the free enzyme. Immobilized StEH was successfully reused in six consecutive hydrolytic kinetic resolutions of rac-pCSO without noticeable loss in activity. Finally, the sequential use of immobilized StEH with the immobilized EH from Aspergillus niger (AnEH) in a repeated batch reactor, operated for five cycles, enabled the enantioconvergent preparation of the corresponding (R)-diol, which was thus obtained with an ee of 89% and an overall yield of 100%.

• Epoxide hydrolase
• Solanum tuberosum
• immobilization
• enantioconvergent process