Iketoine is also called tetrahydromethylpyrimidine carboxylic acid. Ikedoin can protect halophilic bacteria from harm. It has two major functions: 1) moisturizing: it is an important substance to maintain osmotic pressure balance. Its unique molecular structure has strong water molecule complexing ability, which can structure the free water in cells. It is a very excellent natural moisturizing agent. 2) Repair: Ikedoine can resist the damage of ultraviolet rays to skin, and repair the cell DNA damage caused by ultraviolet rays.