An Update: Enzymatic Synthesis for Industrial Applications

Abstract

Supported by rapid technological advancements, biocatalytic applications have matured into sustainable, scalable, and cost-competitive alternatives to established chemical catalysis. This review presents the most recent examples of enzyme-based solutions for the manufacturing of molecules with extended carbon-carbon frameworks and multiple stereogenic centers at commercial scale, including peptide building blocks, (rare) sugars, synthetic (oligo)nucleotides, and terpenoids, such as (-)-Ambrox^®. Novel enzyme classes are highlighted along with their potential applications-the synthesis of DNA/RNA, the depolymerization of synthetic plastics, or fully enzymatic protection/deprotection schemes-pointing toward the diversification and broader industrial utilization of biocatalysis-based processes.

Keywords: Biocatalysis; Enzyme catalysis; Industrial catalysis; Organic synthesis; Stereoselectivity.

Scheme 1

ATA‐ and AmDH‐catalyzed synthesis of optically pure primary amines. a) Transformation of ketones into the corresponding chiral amines by ATA (variants) at the expense of isopropylamine as the amine donor. b) Selected amine intermediates toward the manufacturing of pharmaceuticals through ATA‐driven catalysis. c) AmDH (variants) use cheap ammonia for asymmetric reductive aminations. d) Products of upscaled AmDH‐catalyzed reactions.

Scheme 2

RedAm‐ and IRED‐catalyzed synthesis of optically pure secondary amines. Commercialized processes for the manufacturing of a) an amine intermediate toward abrocitinib, b) cinacalcet from 3‐[3‐(trifluoromethyl)phenyl]propanal and (R)‐1‐(1‐naphthyl)ethanamine, c) a tofacitinib precursor, and d) (S)‐nornicotine.

Scheme 3

Amidase‐catalyzed reactions. Manufacturing of a) a gabapentin precursor, b) (R)‐3,3,3‐trifluoro‐2‐hydroxy‐2‐methylpropionic acid, and c) nicotinyl hydroxamic acid with high STYs. Water molecules are not shown.

Scheme 4

Synthesis of l‐amino acids using sulfhydrylases. The PLP‐dependent activation of amino acid derivatives can yield natural amino acids like l‐Met (top) or various non‐natural amino acids (bottom).

Scheme 5

Enzymatic synthesis of non‐natural l‐amino acids. Protein engineering facilitated and greatly improved the synthesis of a) N‐butyl‐l‐aspartic acid, b) an intermediate toward florfenicol, or c) (4S)‐4‐Phenyl‐l‐homoserine.

Scheme 6

Enlicitid synthesis. a) Structure of enlicitid decanoate with the two building blocks highlighted. b) Initial route to make the 3‐trans hydroxyproline using a ketoreductase (KRED) route. c) Improved route to make the 3‐trans hydroxy proline using an α−KG‐dependent Pro‐hydroxylase, and d) tryptophan synthase‐catalyzed route to afford the fluorinated Trp analog.^{[ 105 ]}

Scheme 7

KRED‐catalyzed synthesis of chiral alcohols. a–c) Utilization of (engineered) KREDs to produce key pharmaceutical intermediates, and d) the value‐added flavor compound (R)‐undecavertol.

Scheme 8

Peroxygenase‐catalyzed regio‐ and stereoselective hydroxylations. a) Up‐scaled production of cyclohexanol from cyclohexane by AaeUPO. b) The highly regiospecific hydroxylation of o‐coumaric acid by UPO2 yielded the value‐added grevillic acid. c) Synthesis of a chiral alcohol by AaeUPO, utilizing O₂ and ascorbic acid (instead of H₂O₂).

Scheme 9

MT‐catalyzed C‐ or N‐alkylations. Different substrates were recently methylated or alkylated for the production of diverse bioactive molecules, including terpenoids (top left) and N‐heterocycles like pyrazoles (top right), benzimidazoles (bottom left), or a physostigmine derivative (bottom right).

Scheme 10

Synthesis of (–)‐Ambrox^® from (E,E)‐homofarnesol catalyzed by a squalene‐hopene‐cyclase (SHC).

Scheme 11

Industrial sugars. a) Structures of d‐allulose, d‐fructose, and d‐tagatose. b) d‐Tagatose production through an enzymatic cascade starting from maltodextrin. α‐GP: 1,4‐α‐glucan phosphorylase; PGM: phosphoglucomutase; PGI: phosphoglucoisomerase; F6PE: fructose‐6‐phosphate‐4‐epimerase; T6PP: tagatose‐6‐phosphate phosphatase; G1P: glucose‐1‐phosphate; G6P: glucose‐6‐phosphate; F6P: fructose‐6‐phosphate; T6P: tagatose‐6‐phosphate.

Scheme 12

Reaction scheme for cellobiose synthesis. ScP, sucrose phosphorylase; CbP: cellobiose phosphorylase; G1P: glucose‐1‐phosphate.

Scheme 13

Manufacturing of ΨMP. A three‐enzyme cascade—combining an uridine phosphorylase (UP), a phosphopentamutase (DeoB), and a nucleoside C‐glycosylase (YeiN)—was developed to synthesize ΨMP.^{[ 186 ]}

Scheme 14

Common building blocks accessible from the depolymerization of PUs and PAs (nylons). a) Hydrolysis of toluene diamine‐based PUs (top) and 4,4′methylene dianiline‐based PUs (bottom) by AS family members yields the corresponding monomers 2,4‐toluene diamine and 4,4′‐methylene dianiline, respectively. b) NylC‐type nylonases and AS enzymes are currently investigated for their (poly)amidase activity toward different PAs. Hydrolysis of nylon 6 produces 6‐aminohexanoic acid (left). The depolymerization of nylon 4,6 (x  =  1) and nylon 6,6 (x  =  3) yields hexane‐1,6‐diamine, besides succinic acid and adipic acid, respectively (right).