Shikimic acid is a white crystalline compound of nonnitrogenous acid found in various plants naturally. It has two kind functional groups in the same molecule, three hydroxyl groups and a carboxylic acid group, which are optically active. They can yield various kinds of esters and salts. Shikimic acid is a cyclitol, a polyhydroxylated cycloalkane containing at least three hydroxy groups in the ring at different positions. Examples are inositol and quinic acid. The most important feature of cyclitol is that there are chiral isomers, key intermediates in the biosynthesis of aromatic compounds in living metabolism. Shikimic acid is a key intermediate in the biochemical pathway from phosphoenolpyruvic acid to tyrosine.