Enantioconvergent production of (R)‐1‐phenyl‐1,2‐ethanediol from styrene oxide by combining the Solanum tuberosum and an evolved Agrobacterium radiobacter AD1 epoxide hydrolases

Abstract

Soluble epoxide hydrolase (EH) from the potato Solanum tuberosum and an evolved EH of the bacterium Agrobacterium radiobacter AD1, EchA-I219F, were purified for the enantioconvergent hydrolysis of racemic styrene oxide into the single product (R)-1-phenyl-1,2-ethanediol, which is an important intermediate for pharmaceuticals. EchA-I219F has enhanced enantioselectivity (enantiomeric ratio of 91 based on products) for converting (R)-styrene oxide to (R)-1-phenyl-1,2-ethanediol (2.0 +/- 0.2 micromol/min/mg), and the potato EH converts (S)-styrene oxide primarily to the same enantiomer, (R)-1-phenyl-1,2-ethanediol (22 +/- 1 micromol/min/mg), with an enantiomeric ratio of 40 +/- 17 (based on substrates). By mixing these two purified enzymes, inexpensive racemic styrene oxide (5 mM) was converted at 100% yield to 98% enantiomeric excess (R)-1-phenyl-1,2-ethanediol at 4.7 +/- 0.7 micromol/min/mg. Hence, at least 99% of substrate is converted into a single stereospecific product at a rapid rate.

Crystal structure of a carbonyl reductase from Candida parapsilosis with anti‐Prelog stereospecificity

“…It is the only known SDR that catalyzes the enantioselective reduction of 2-hydroxyacetophenone to produce the valuable, optically active 1-phenyl-1, 2-ethanediol with high yield and chiral purity (Wei et al 2000;Cao et al 2006;Supplemental Fig. 1).…”

Comparative homology modeling-inspired protein engineering for improvement of catalytic activity of Mugil cephalus epoxide hydrolase

“…radiobacter AD1 was also engineered by DNA shuffling and saturation mutagenesis. The mutant with L190F showed a 4.8-fold enhanced catalytic activity (Cao et al 2006;Rui et al 2004Rui et al , 2005. All these results clearly showed the potential of protein engineering and directed evolutions to improve catalytic properties of microbial EHs.…”

Epoxide hydrolase-mediated enantioconvergent bioconversions to prepare chiral epoxides and alcohols

“…p-Nitrostyrene oxide was enantioconvergently transformed to the corresponding diol in up to 99%ee and 68.7% yield by using two novel plant EHs from mung bean (Xu et al 2006). One noticeable enantioconvergent hydrolysis for the preparation of (R)-phenyl-1,2-ethanediol was conducted by using the directed evolved EH (Cao et al 2006;Rui et al 2005). The EH of Agrobacterium radiobacter AD1 was engineered to enhance the enantioselectivity by saturation mutagenesis and DNA shuffling techniques.…”