L-leucine is one of the eight essential amino acids for the human body. It belongs to the aliphatic amino acids in the twenty protein amino acids. Together with L-isoleucine and L-valine, it is called the three major branched chain amino acids. It is an enantiomer with D-leucine, and it is a white glossy hexahedral crystal or a white crystalline powder at room temperature. Odorless, slightly bitter. In the presence of hydrocarbons, the performance is stable in mineral acid aqueous solutions. Dissolve each gram in 40ml of water and about 100ml of acetic acid. Very slightly soluble in ethanol or ether, soluble in formic acid and dilute hydrochloric acid, alkaline hydroxide and carbonate solutions.