Improved Synthesis of Furfurylamine from a High Titer of Biomass- Derived Furfural by a Thermostable Triple Mutant omega-Transaminase in a Three-Component Deep Eutectic Solvent ChCl/Lactic Acid/ Malonic Acid System

Furfurylamine (FLA) is widely utilized in manufacturing polymers, food additives, fibers, fuel additives, flavors, and pharmaceut-icals. Lignocellulose was tandemly transformed to furfurylamine by combining chemocatalysis with biocatalysis in a three-component deep eutectic solvent (3c-DES)-H2O in this work. Biomass-derived D-xylose (300 mM) was transformed with 3c-DES ChCl/MA/LA (15 wt %) [choline chloride (ChCl), malonic acid (MA), and lactic acid (LA)] at 190 degrees C for 45 min to produce furfural (70.6% yield). A robust triple mutant Aspergillus terreus ?-transaminase HNILQE with high biocatalytic activity and thermostability was obtained through a consensus strategy [Q97E (glutamine to glutamic acid), H210N (histidine to asparagine), I77L (isoleucine to leucine)]. HNILQE could aminate D-xylose-derived furfural to furfurylamine (97.6% yield), reaching a productivity of 0.98 g furfurylamine/g furfural (cal. 0.44 g furfurylamine/g D-xylose). High titer of biobased furfural (500 mM) was transformed to FLA (95.8% yield, >99% selectivity) in ChCl/MA/LA-H2O. A highly efficient manufacture of furfurylamine from high loading of furfural by this robust triple mutant HNILQE biocatalyst was successfully realized in the established eco-friendly medium. This established chemoenzymatic process can be utilized for efficient manufacture of biobased furans in the green and sustainable approach.