Immobilization of Prunus amygdalus Hydroxynitrile Lyase on Celite

Paula Bracco,Ulf Hanefeld,Guzman Torrelo,Glenn De Jong,Sander Noordam

doi:10.3390/catal8070287

Abstract

The hydroxynitrile lyase from Prunus amygdalus was immobilized on Celite R-633. The immobilized enzyme could successfully be utilized in buffer saturated MTBE and excellent conversions of benzaldehyde to R-mandelonitrile were observed. No leaching occurred. To achieve high enantioselectivities, the suppression of the undesired background reaction was essential. This could be achieved by high enzyme loadings and the tight packing of the immobilized enzymes. When the immobilized enzyme is loosely packed, both the enzyme catalysis and the background reaction accelerates and only a modest enantioselectivity is observed. The enzyme was recycled for up to ten times, with some loss of activity and also enantioselectivity after 5 cycles, independent of packing.

Highlights

In 1837, the first application of a Hydroxynitrile lyase (HNL), namely Prunus amygdalus HNL (PaHNL), was reported
Ever since the first report of the reverse reaction, the stereoselective synthesis catalyzed again by PaHNL in 1908, HNLs are the catalyst of choice for the enantioselective synthesis of cyanohydrins
We describe the immobilization of PaHNL on Celite to address both problems

Summary

Introduction

In 1837, the first application of a Hydroxynitrile lyase (HNL), namely Prunus amygdalus HNL (PaHNL), was reported. HNLs are an essential part of chemical warfare to defend plants and animals by the release of toxic HCN [1,2,3] They achieve this by catalyzing the release of HCN from natural cyanohydrins. Ever since the first report of the reverse reaction, the stereoselective synthesis catalyzed again by PaHNL in 1908, HNLs are the catalyst of choice for the enantioselective synthesis of cyanohydrins. Their use in the laboratory and factory is well established [1,2,3,4,5]. We look at the density of packing the immobilized enzyme

Methods

Results

Discussion

Conclusion