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

Arabidopsis thaliana hydroxynitrile lyase (AtHNL) engineering has uncovered variants that showed up to 12-fold improved catalytic efficiency than the wild-type towards asymmetric Henry reaction. The AtHNL 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.