title: Curcuminoid biosynthesis by two type III polyketide synthases in the herb Curcuma longa.
abstract: Curcuminoids found in the rhizome of turmeric, Curcuma longa, possess various biological activities. Despite much attention regarding the biosynthesis of curcuminoids because of their pharmaceutically important properties and biosynthetically intriguing structures, no enzyme systems have been elucidated. Here we propose a pathway for curcuminoid biosynthesis in the herb C. longa, which includes two novel type III polyketide synthases. One of the type III polyketide synthases, named diketide-CoA synthase (DCS), catalyzed the formation of feruloyldiketide-CoA by condensing feruloyl-CoA and malonyl-CoA. The other, named curcumin synthase (CURS), catalyzed the in vitro formation of curcuminoids from cinnamoyldiketide-N-acetylcysteamine (a mimic of the CoA ester) and feruloyl-CoA. Co-incubation of DCS and CURS in the presence of feruloyl-CoA and malonyl-CoA yielded curcumin at high efficiency, although CURS itself possessed low activity for the synthesis of curcumin from feruloyl-CoA and malonyl-CoA. These findings thus revealed the curcumin biosynthetic route in turmeric, in which DCS synthesizes feruloyldiketide-CoA, and CURS then converts the diketide-CoA esters into a curcuminoid scaffold.
authors.affiliation: Department of Biotechnology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Katsuyama
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kita
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Funa
authors.forename: Sueharu
authors.initials: S
authors.lastname: Horinouchi
mesh_terms: D000214:Acyl Coenzyme A / Q000378:metabolism; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D030024:Curcuma / Q000378:metabolism*; D004952:Esters; D007700:Kinetics; D008316:Malonyl Coenzyme A / Q000378:metabolism; D008956:Models, Chemical; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D048630:Polyketide Synthases / Q000378:metabolism*; D013053:Spectrophotometry / Q000379:methods; D013997:Time Factors
chemical_list: D000214:Acyl Coenzyme A; D004952:Esters; D010936:Plant Extracts; C119167:feruloyl-CoA; D008316:Malonyl Coenzyme A; D048630:Polyketide Synthases; C012596:turmeric extract