The source and chemistry of curcumin. a Turmeric powder is obtained from the roots of plant Curcuma longa.
b Curcumin is a component of turmeric. c The chemical structure of curcumin demonstrates a bis a, b-unsaturated diketone structure that displays keto enol tautomerism, with a predominant keto form in acidic and neutral solutions and a stable enol form in alkaline media. d The chemical structure of demethoxycurcumin and bisdemethoxycurcumin