One‐Pot Biocatalytic In Vivo Methylation‐Hydroamination of Bioderived Lignin Monomers to Generate a Key Precursor to L‐DOPA

Abstract Electron‐rich phenolic substrates can be derived from the depolymerisation of lignin feedstocks. Direct biotransformations hydroxycinnamic acid monomers obtained exploited to produce high‐value chemicals, such as α‐amino acids, however reaction is often hampered by chemical autooxidation in alkaline or harsh media. Regioselective O ‐methyltransferases (OMTs) are ubiquitous enzymes natural secondary metabolic pathways utilising an expensive co‐substrate S ‐adenosyl‐ l ‐methionine (SAM) methylating reagent altering physicochemical properties acids. In this study, we engineered OMT accept a variety electron‐rich substrates, modified commercial E. coli strain BL21 (DE3) regenerate SAM vivo, and combined it with ammonia lyase partake one‐pot, two whole cell enzyme cascade ‐DOPA precursor ‐veratrylglycine lignin‐derived ferulic acid.