Highly efficient and large-scalable glucoamylase-catalyzed Henry reactions

Abstract

Eco-friendly, highly efficient and large-scalable Henry reactions of aromatic aldehydes and nitroalkanes catalyzed by glucoamylase from Aspergillus niger (AnGA) are described. The reactions were carried out at 30 °C in the mixed solvents of ethanol and water, and the corresponding β-nitro alcohols were obtained in yields of up to 99%. Only 3 mg of enzyme was sufficient to catalyze the reaction of 1 mmol aldehydes. The natural activity and promiscuous activity of AnGA were compared under different conditions. Experiments demonstrated that the product of the Henry reaction could inhibit AnGA at 80 °C. This enzymatic Henry reaction showed a broad substrate scope, and could be facilely enlarged to gram scale. The possible mechanism was also discussed.