title: Bacterial synthesis of N-hydroxycinnamoyl phenethylamines and tyramines.
abstract: BACKGROUND
  Hydroxycinnamic acids (HCAs) including cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid, are C6-C3 phenolic compounds that are synthesized via the phenylpropanoid pathway. HCAs serve as precursors for the synthesis of lignins, flavonoids, anthocyanins, stilbenes and other phenolic compounds. HCAs can also be conjugated with diverse compounds including quinic acid, hydroxyl acids, and amines. Hydroxycinnamoyl (HC) amine conjugates such as N-HC tyramines and N-HC phenethylamines have been considered as potential starting materials to develop antiviral and anticancer drugs.
  
  
  RESULTS
  We synthesized N-HC tyramines and N-HC phenethylamines using three different approaches in Escherichia coli. Five N-HC phenethylamines and eight N-HC tyramines were synthesized by feeding HCAs and phenethylamine or tyramine to E. coli harboring 4CL (encoding 4-coumarate CoA:ligase) and either SHT (encoding phenethylamine N-HC transferase) or THT (encoding tyramine N-HC transferase). Also, N-(p-coumaroyl) phenethylamine and N-(p-coumaroyl) tyramine were synthesized from p-coumaric acid using E. coli harboring an additional gene, PDC (encoding phenylalanine decarboxylase) or TDC (encoding tyrosine decarboxylase). Finally, we synthesized N-(p-coumaroyl) phenethylamine and N-(p-coumaroyl) tyramine from glucose by reconstructing the metabolic pathways for their synthesis in E. coli. Productivity was maximized by optimizing the cell concentration and incubation temperature.
  
  
  CONCLUSIONS
  We reconstructed the metabolic pathways for synthesis of N-HC tyramines and N-HC phenethylamines by expressing several genes including 4CL, TST or SHT, PDC or TDC, and TAL (encoding tyrosine ammonia lyase) and engineering the shikimate metabolic pathway to increase endogenous tyrosine concentration in E. coli. Approximately 101.9 mg/L N-(p-coumaroyl) phenethylamine and 495.4 mg/L N-(p-coumaroyl) tyramine were synthesized from p-coumaric acid. Furthermore, 152.5 mg/L N-(p-coumaroyl) phenethylamine and 94.7 mg/L N-(p-coumaroyl) tyramine were synthesized from glucose.
authors.affiliation: Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul, 143-701, Republic of Korea. kingyi92@naver.com.
authors.forename: Geun Young
authors.initials: GY
authors.lastname: Sim
authors.affiliation: Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul, 143-701, Republic of Korea. lcanldyl@nate.com.
authors.forename: So-Mi
authors.initials: SM
authors.lastname: Yang
authors.affiliation: Department of Forest Resources, Gyeongnam National University of Science and Technology, 33 Dongjin-ro, Jinju-si, Gyeongsangman-do, 660-758, Republic of Korea. dkimbk@gntech.ac.kr.
authors.forename: Bong Gyu
authors.initials: BG
authors.lastname: Kim
authors.affiliation: Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul, 143-701, Republic of Korea. jhahn@konkuk.ac.kr.
authors.forename: Joong-Hoon
authors.initials: JH
authors.lastname: Ahn
mesh_terms: D003066:Coenzyme A Ligases / Q000235:genetics / Q000378:metabolism; D003373:Coumaric Acids / Q000737:chemistry / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D013058:Mass Spectrometry; D060847:Metabolic Engineering; D010627:Phenethylamines / Q000737:chemistry / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D014166:Transferases / Q000235:genetics / Q000378:metabolism; D014439:Tyramine / Q000737:chemistry / Q000378:metabolism*
chemical_list: D003373:Coumaric Acids; D029968:Escherichia coli Proteins; D010627:Phenethylamines; D014166:Transferases; D003066:Coenzyme A Ligases; C019943:4-coumarate-CoA ligase; D014439:Tyramine