Turmeric, curcumin and its chemical structure. (a) The root of turmeric. (b) Crystallized powder of curcumin. Curcumin is thought to be the main active ingredient derived from the root of turmeric. (c) The enol and keto forms of curcumin are common structures of the drug. The enol form is more energetically stable in the solid phase and in solution [6]. Figures 1(a) and 1(b) are from http://www.skinvitality.ca/blog/2012/06/curcumin-cancer-treatment#.UnGdC7KBSnQ and http://en.wikipedia.org/wiki/Curcumin.
