Production of (R)-mandelic acid from styrene, L-phenylalanine, glycerol, or glucose via cascade biotransformations

Abstract ( R ) - mandelic acid is an industrially important chemical, especially used for producing antibiotics. Its chemical synthesis often uses highly toxic cyanide to produce its racemic form, followed by kinetic resolution with 50% maximum yield. Here we report a green and sustainable biocatalytic method )-mandelic from easily available styrene, biobased L- phenylalanine, renewable feedstocks such as glycerol glucose, respectively. An epoxidation-hydrolysis-double oxidation artificial enzyme cascade was developed at 1.52 g/L styrene > 99% ee . Incorporation of deamination decarboxylation into the above enables direct conversion phenylalanine 913 mg/L Expressing five-enzyme in L -phenylalanine-overproducing E. coli NST74 strain led or affording 228 152 product via fermentation. Moreover, coupling cells expressing -phenylalanine biosynthesis pathway enabled production 760 455 glucose. These simple, safe, methods show great potential feedstocks.