2-Amino-6-[(1S,2R)-1,2-dihydroxypropyl]-5,6,7,8-tetrahydropteridine-4(1H)-one
Tetrahydrobiopterin is a cofactor that is essential for the activity of aromatic amino acid hydroxylases. Tetrahydrobiopterin degrades phenylalanine, and facilitates the biosynthesis of several neurotransmitters and the production of nitric oxide.