Hydroxynitrile lyase engineering for promiscuous asymmetric Henry reaction with enhanced conversion, enantioselectivity and catalytic efficiency.

Arabidopsis thaliana hydroxynitrile lyase ( At HNL) engineering has uncovered variants that showed up to 12-fold improved catalytic efficiency than the wild-type towards asymmetric Henry reaction. The At HNL variants have displayed excellent enantioselectivity, up to >99%, and higher conversion in the synthesis of 13 different ( R )-β-nitroalcohols from their corresponding aldehydes. Using cell lysates of Y14M/F179W, we demonstrated a preparative scale synthesis of ( R )-1-(4-methoxyphenyl)-2-nitroethanol, a tembamide chiral intermediate, in >99% ee and 52% yield.