Conversion of Furans by Baeyer-Villiger Monooxygenases

Hemant Kumar,Marco Fraaije

doi:10.3390/catal7060179

Abstract

Various furans are considered as valuable platform chemicals as they can be derived from plant biomass. Yet, for their exploitation, follow-up chemistry is required. Here we demonstrate that Baeyer-Villiger monooxygenases (BVMOs) can be used as biocatalysts for the selective oxidation of several furans, including 5-(hydroxymethyl) furfural (HMF) and furfural. A total of 15 different BVMOs were tested for their activity on furfural, which revealed that most of the biocatalysts were active on this aromatic aldehyde. Phenylacetone monooxygenase (PAMO) and a mutant thereof (PAMOM446G) were selected for studying their biocatalytic potential in converting furfural and some other furans. While BVMOs are usually known to form an ester or lactone as a ‘normal’ product by inserting an oxygen atom adjacent to the carbonyl carbon of the substrate, our results reveal that both biocatalysts produce furanoid acids as the main product from the corresponding aldehydes. Altogether, our study shows that BVMOs can be employed for the selective oxidation of furans.

Highlights

Due to limited fossil reserves and concern over environmental pollution, the search for new routes towards biomass-derived products has intensified in the last decade
As part of our efforts to develop Baeyer-Villiger monooxygenases (BVMOs) as valuable biocatalysts, we have studied these enzymes for2.1
phosphite dehydrogenase (PTDH)-Phenylacetone monooxygenase (PAMO) and mutants thereof have been well studied, are expressed, and represent rather robust biocatalysts [17]. This revealed the ability of PAMO and the PAMO mutant to convert furfural, HMF, and related compounds

Summary

Introduction

Due to limited fossil reserves and concern over environmental pollution, the search for new routes towards biomass-derived products has intensified in the last decade. One class of compounds that can be prepared from plant biomass are furans. These aromatic compounds can be prepared from lignocellulose material by the acid-catalysed dehydration of sugars. Known plant biomass-derived furans are furfural and 5-(hydroxymethyl)furfural (HMF) [1]. HMF is regarded as a highly promising platform chemical for the synthesis of furan-2,5-dicarboxylic acid (FDCA). FDCA can be used for the synthesis of polyethylene furanoate (PEF), a promising polyester. Besides PEF, there are various other compounds of interest that can be synthesized using FDCA as a starting material [2]. Furfural is considered as a renewable platform chemical with high potential as it can serve as a precursor for many types of value-added products [3]

Methods

Results

Conclusion