Scheme 2. Novel enzymes, enzymatic mechanisms and cascades for the synthesis of benzylisoquinoline alkaloids and related tetrahydroisoquinolines. NCS: norcoclaurine synthase; BBE: berberine bridge enzyme; STORR: (S)- to (R)-reticuline epimerase; SalSyn: salutaridine synthase; TfNCS: norcoclaurine synthase from Thalictrum flavum; IR45: imine reductase from Streptomyces aurantiacus; CNMT: coclaurine N-methyltransferase; IRED: imine reductase; MAO-N: monoamine oxidase from Aspergillus niger; CHAO: cyclohexylamine oxidase; DAAO: d-amino acid oxidase; DpkA: piperidine-2-carboxylate reductase from Pseudomonas putida.
