Tetrahydrocurcuminoids (THC) is the main product of curcumin metabolism in the human body, obtained by hydrogenation of curcumin. THC is an odorless white powder that is more hydrophilic than curcumin. It has been used as a raw material for various skincare products in the research and development of cosmetics and has broad development.

2-Ethyl anthraquinone is an organic compound with the chemical formula C16H12O2. It is derived from anthraquinone, which is a polycyclic aromatic hydrocarbon. 2-Ethyl anthraquinone has a molecular structure in which an ethyl group (C2H5) is attached to the anthraquinone molecule.