Turmeric: old spice, new spice

Abstract

The history of chemical investigations into the yellow components of turmeric can be traced from 1815. Although the major yellow component of turmeric, curcumin, often is represented as a 1,3-diketone in the solid state and in nonaqueous solution, it exists in the enol form. The struggle to identify the chemical structure of curcumin continued for nearly a century and was complicated by the difficult purification of curcumin and by the presence of two additional yellow components. Food remains the main use for turmeric (old spice); its use as a dye has diminished since the 19th century, but it may have pharmaceutical uses (new spice).

Key words:

• curcumin
• history
• keto-enol
• turmeric
• yellow dye

Declaration of interest: The author reports no conflicts of interest. The author alone is responsible for the content and writing of this paper.