Biotransamination of Furan‐Based Aldehydes with Isopropylamine: Enzyme Screening and pH Influence

Abstract

Furan‐based amines are highly valuable compounds which can be directly obtained via reductive amination from easily accessible furfural, 5‐(hydroxymethyl)furfural (HMF) and 2,5‐diformylfuran (DFF). Herein the biocatalytic amination of these carbonyl derivatives is disclosed using amine transaminases (ATAs) and isopropylamine (IPA) as amine donor. Among the different biocatalysts tested, the ones from Chromobacterium violaceum (Cv‐TA), Arthrobacter citreus (ArS‐TA), and variants from Arthrobacter sp. (ArRmut11‐TA) and Vibrio fluvialis (Vf‐mut‐TA), afforded high levels of product formation (>80%) at 100‐200 mM aldehyde concentration. The transformations were studied in terms of enzyme and IPA loading. The pH influence was found as a key factor and attributed to the imine/aldehyde equilibrium that can arise from the high reactivity of the carbonyl substrates with a nucleophilic amine such as IPA.

Spectrophotometric Assay for the Detection of 2,5-Diformylfuran and Its Validation through Laccase-Mediated Oxidation of 5-Hydroxymethylfurfural

“…This parameter offers a DMSO has a beneficial effect on organic substrate solubilities, providing a one-phase system, and its efficiency in enzymatic reactions has been previously proven with many enzyme classes (ADHs, ATAs, etc.) [81][82][83]. Also, the three laccases were previously efficiently tested at high DMSO concentrations, revealing a good stability [84,85].…”