L-Isoleucine also known as 2-Amino-3-methyl pentanoic acid, is an essential amino acid that is not synthesized in the body and must be obtained from dietary sources. It is one of the three branched-chain amino acids, along with L-leucine and L-valine, that play important roles in protein synthesis, muscle repair and growth, energy production, and immune function. 73-32-5 L-Isoleucine is an important amino acid that plays a critical role in maintaining overall health and wellness.