Editing Curcumin (section)

===Biosynthesis===
The biosynthetic route of curcumin is uncertain. In 1973, Peter J. Roughley and Donald A. Whiting proposed two mechanisms for curcumin biosynthesis. The first mechanism involves a chain extension reaction by [[cinnamic acid]] and 5 [[malonyl-CoA]] molecules that eventually arylize into a curcuminoid. The second mechanism involves two cinnamate units coupled together by malonyl-CoA. Both use cinnamic acid as their starting point, which is derived from the amino acid [[phenylalanine]].<ref name="Kita, T. 2008" />

Plant biosynthesis starting with cinnamic acid is rare compared to the more common [[p-Coumaric acid|''p''-coumaric acid]].<ref name="Kita, T. 2008">{{cite journal | vauthors = Kita T, Imai S, Sawada H, Kumagai H, Seto H | title = The biosynthetic pathway of curcuminoid in turmeric (Curcuma longa) as revealed by 13C-labeled precursors | journal = Bioscience, Biotechnology, and Biochemistry | volume = 72 | issue = 7 | pages = 1789–1798 | date = July 2008 | pmid = 18603793 | doi = 10.1271/bbb.80075 | doi-access = free }}</ref> Only a few identified compounds, such as [[anigorufone]] and [[pinosylvin]], build from cinnamic acid.<ref>{{cite journal | vauthors = Schmitt B, Hölscher D, Schneider B | title = Variability of phenylpropanoid precursors in the biosynthesis of phenylphenalenones in Anigozanthos preissii | journal = Phytochemistry | volume = 53 | issue = 3 | pages = 331–337 | date = February 2000 | pmid = 10703053 | doi = 10.1016/S0031-9422(99)00544-0 | bibcode = 2000PChem..53..331S }}</ref><ref>{{cite journal | vauthors =  Gehlert R, Schoeppner A, Kindl H |title= Stilbene Synthase from Seedlings of ''Pinus sylvestris'': Purification and Induction in Response to Fungal Infection |journal= Molecular Plant-Microbe Interactions |year= 1990 |volume= 3 |issue= 6 |pages= 444–449 |doi= 10.1094/MPMI-3-444 |url= http://www.apsnet.org/publications/mpmi/backissues/Documents/1990Articles/Microbe03_444.pdf }}</ref>

[[File:Curcumin biosynthesis.svg|500px|center|thumb|class=skin-invert-image|alt= Curcumin biosynthesis diagram|Biosynthetic pathway of curcumin in ''[[Curcuma longa]]''.<ref name="Kita, T. 2008"/>]]