Enzymatic Resolution by a d‐Lactate Oxidase Catalyzed Reaction for (S)‐2‐Hydroxycarboxylic Acids

Abstract

Oxidase‐catalyzed kinetic resolution is important for the production of enantiopure 2‐hydroxycarboxylic acids (2‐HAs), which are versatile building blocks for the synthesis of many significant compounds. However, in contrast to that of (R)‐2‐HAs, the production of (S)‐2‐HA is challenging because of the lack of related oxidases. Herein, suitable enzymes were screened systematically through the analysis of numerous putative d‐lactate oxidase sequences and identification of several required properties. Finally, a d‐lactate oxidase from Gluconobacter oxydans 621H with advantageous characteristics, such as good solubility, broad substrate spectrum, and high stereoselectivity, was selected to resolve 2‐HAs into (S)‐2‐HAs. A variety of (S)‐2‐HAs was produced successfully using this d‐lactate oxidase with excellent enantiomeric excess values (>99 %). The presented screening criteria and approach for target biocatalysis suggested a guideline for the production of optically active chemicals such as (S)‐2‐HAs.

Biocatalytic Oxidative Cascade for the Conversion of Fatty Acids into α‐Ketoacids via Internal H2O2 Recycling

“…36 % ee. This set akey requirement for the successful quantitative conversion of 1 into 3 in ac ascade reaction (Scheme 1), as formation of the intermediate product 2 with moderate ee values necessitates the employment of two stereocomplementary oxidases in the second step of the cascade.T ot hat end, we selected (S)specific a-hydroxyacid oxidase from Aerococcus viridans [(S)-a-HAO] [17] and ar ecently identified d-lactate oxidase from Gluconobacter oxydans (GO-LOX) [18] reported to be (R)-specific for several short-chain 2-hydroxyacids [(R)-a-HAO].Both a-HAOs were tested for activity on rac-2 in the presence of acatalase and were found to be active and highly enantioselective.B oth (R)-and (S)-2 were obtained in enantiomerically pure form upon action of (S)-a-HAOa nd GO-LOX, respectively (Schemes S1 and S2 and Figure S5).…”

Production of Ethylene Glycol from Glycerol Using an In Vitro Enzymatic Cascade

“…The target product of this study, ethylene glycol, is the simplest 1,2-diol, and is also the possible substrate of AldO mt . Thus, the activity of AldO mt toward ethylene glycol was assayed using a Clark-type oxygen electrode, as described in a previous study [24]. As shown in Figure 2a, the AldO mt -dependent oxygen consumption was rather low with the addition of ethylene glycol, while noticeable oxygen consumption was observed when glycerol was added ( Figure 2c).…”

Enzymatic Cascades for Efficient Biotransformation of Racemic Lactate Derived from Corn Steep Water

“…To exploit a technologically and economically feasible in vitro process based on racemic lactate, the fundamental principle is as follows: Minimize the number of enzymes required, and avoid exogenous addition of costly coenzymes. , l -LOX, which is able to oxidize l -lactate and transfer electrons directly to O 2 to form pyruvate and H 2 O 2 , undoubtedly satisfies the demand for in vitro catalysis. Recently, we identified GOX2071 from G. oxydans as a d -LOX that could catalyze the oxidization of d -lactate with O 2 . , This enzyme exhibits catalytic properties similar to those of l -LOX, except for the stereoselectivity. Thus, coproduction of pyruvate and optically pure lactate from racemic lactate could be realized by selectively using l -LOX or d -LOX (Figure ).…”