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

Abstract

Furfurylamine (FLA) is widely utilized in manufacturing polymers, food additives, fibers, fuel additives, flavors, and pharmaceuticals. 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 °C for 45 min to produce furfural (70.6% yield). A robust triple mutant Aspergillus terreus ω-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.

Acid-catalyzed transformation of orange waste into furfural: the effect of pectin degree of esterification

“…It is produced from d -GalA but unlike arabinose its concentration remains unchanged for several hours of reaction time. However, the use of another solvent could increase the conversion, for instance, the use of deep eutectic solvents results in a furfural yield of more than 50% from xylose at 170 °C in 30 min (Liu et al 2023b ; Yang et al 2023a , b ; Xu et al 2023 ; Lei et al 2023 ); under similar conditions if water is used as a solvent the conversion of xylose is barely perceptible after 4 h of reaction time (this work). Also, the possibility of increasing the furfural yield with a heterogeneous catalyst should be explored.…”

“…The possibility of co-production of essential oil, pectin and furfural is not the only possibility as other researchers have found. Within the biorefinery, furfural could be used to obtain other compounds as it is demonstrated in the production of furfurylamine, furfuryl alcohol and furoic acid (Liu et al 2023a ; Lei et al 2023 ; Yang et al 2023b ; Xu et al 2023 ). Other possibilities open up if the residual biomass is pyrolyzed to produce biochar (Yang, et al 2023a , b ) that could be the base of heterogeneous catalysts that could be used in the hydrolysis process.…”

One-pot chemo- and photo-enzymatic linear cascade processes

“…To increase thermostability and catalytic activity in the presence of high substrate concentration, the authors developed mutant transaminase strains using side-directed mutagenesis. 325–327 For instance, the authors showed that a triple mutant Aspergillus terreus ω-transaminase (HNILQE) could aminate furfural into furfuryl amine in high yield at 500 mM furfural concentration, which is considerably superior to the usual concentrations (100–300 mM) used for the wild-type strain transaminases. The chemo-enzymatic process proceeded in a three-component DES (choline chloride–malonic acid–lactic acid) that acted as a solvent and as an acid catalyst.…”

“…The chemo-enzymatic process proceeded in a three-component DES (choline chloride–malonic acid–lactic acid) that acted as a solvent and as an acid catalyst. Starting from d -xylose the dehydration step was performed at 190 °C for 45 min, giving furfural (70.6% yield), which was aminated by the enzyme mutant after adjusting the pH to 8 and the temperature (35 °C), affording the furfuryl amine in 97.6% yield after 24 h. 325…”

Electron-Rich Ru Supported on N-Doped Coffee Biochar for Selective Reductive Amination of Furfural to Furfurylamine

“…Production of amines from renewable resources is a hot topic of research in recent years and has been recognized as a sustainable and environmentally friendly way. − Furfural can be derived from cellulose and was listed as one of the 12 potential biomass platform chemicals by the United States Department of Energy in 2004 . Furfurylamine, one of the most important primary amines, has been highly regarded due to its widespread use in the manufacture of pharmaceuticals and pesticides. , Therefore, selective synthesis of furfurylamine from renewable furfural has a positive effect on mitigating the energy crisis and environmental pollution.…”