Polyphosphazenes as Tunable and Recyclable Supports To Immobilize Alcohol Dehydrogenases and Lipases: Synthesis, Catalytic Activity, and Recycling Efficiency

The polyphosphazene {NP[O2C12H7.5(NH2)(0.5])}(n), prepared by reacting {NP[O2C12H7.5(NO2)(0.5)]} with the Lalancette's reagent, was used for attaching enzymes such as alcohol dehydrogenase (ADH-A) and lipase (CAL-B). The resulting new biocatalysts exhibited great potential as tunable supports for enzymatic reactions in both aqueous and organic media. The material with immobilized ADH-A was as efficient as the commercial enzyme to perform stereoselective bioreductions of ketones in aqueous solutions and could be used for the reduction of various aliphatic and aromatic ketones up to 60 degrees C and recycled several times without significant loss of activity even after three months of storage. The biocatalyst obtained with CAL-B was more efficient than the free enzyme for kinetic resolutions in organic solvents and exhibited a moderately good capability of reutilization.