Biocatalytic Production of Amino Carbohydrates through Oxidoreductase and Transaminase Cascades

Plant‐derived carbohydrates are an abundant renewable resource. Transformation of carbohydrates into new products, including amine‐functionalized building blocks for biomaterials applications, can lower reliance on fossil resources. Herein, biocatalytic production routes to amino carbohydrates, including oligosaccharides, are demonstrated. In each case, two‐step biocatalysis was performed to functionalize d‐galactose‐containing carbohydrates by employing the galactose oxidase from Fusarium graminearum or a pyranose dehydrogenase from Agaricus bisporus followed by the ω‐transaminase from Chromobacterium violaceum (Cvi‐ω‐TA). Formation of 6‐amino‐6‐deoxy‐d‐galactose, 2‐amino‐2‐deoxy‐d‐galactose, and 2‐amino‐2‐deoxy‐6‐aldo‐d‐galactose was confirmed by mass spectrometry. The activity of Cvi‐ω‐TA was highest towards 6‐aldo‐d‐galactose, for which the highest yield of 6‐amino‐6‐deoxy‐d‐galactose (67 %) was achieved in reactions permitting simultaneous oxidation of d‐galactose and transamination of the resulting 6‐aldo‐d‐galactose.