Leucine is one of the eight essential amino acids, and belonging to the aliphatic amino acids within twenty kinds of proteins. L-leucine and L-isoleucine and L-valine are called three branched chain amino acids. L-leucineLeucine and D-leucine are enantiomers . It is a white shiny hexahedral crystal or white crystalline powder at room temperature , Odorless, slightly bitter . In the presence of hydrocarbons ,it is stable in the aqueous mineral acid. Per gram is dissolved in 40ml water and about 100ml acetic acid. Very slightly soluble in ethanol or ether, dissolved in formic acid, dilute hydrochloric acid, a solution of alkali hydroxides and a solution of carbonates.