Curcumin (1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione), also called Diferuloylmethane, is the main natural polyphenol found in the rhizome of Curcuma Longa (Turmeric) and in others Curcuma spp.

Among the Curcuma species, Curcuma Longa L. (Curcuma; Turmeric) is the most widely recognized; a cultivated plant, grown in a warm climate, in many regions of the world. Rhizomes are the most commonly used plant part, composed of a wide variety of compounds, including the bioactive non-volatile Curcuminoids (Curcumin, dimethoxy-, and bisdemethoxy-curcumin) and the compounds present in volatile oil (mono and sesquiterpenoids).

In brief, Curcumin is a Diferuloylmethane with a crystalline yellow-orange colour. Curcumin is found primarily in roots and rhizomes of the Turmeric plant (Curcuma Longa). In addition to Curcumin, two other Curcuminoids occur in lesser amounts in Turmeric, namely, Demethoxycurcumin (DMC) and Bis-demethoxycurcumin (BDMC).