Cyclocurcumin

Cyclocurcumin is a minor curcuminoid derived from the rhizome of Curcuma longa that differs structurally from curcumin despite sharing the same molecular formula (C21H20O6), Cyclocurcumin features an α, β-unsaturated dihydropyranone moiety that drives trans–cis photoisomerization instead of the diketone/keto–enol tautomerism characteristic of curcumin. Cyclocurcumin demonstrates potent biochemical activities, including selective inhibition of human aromatase (CYP19A1) with an IC50 of 4.43 μM—approximately fivefold stronger than curcumin—making it valuable for studying estrogen-related pathways, and uniquely stimulates melanogenesis and melanin export in both melanocyte and melanoma models, positioning it as a promising research tool for investigating hypopigmentary skin disorders.