Tryptophan is an amino acid essential to survival. Amino acids serve as building blocks for proteins, as well as serving as starting points for the synthesis of vitamins and many other crucial cellular molecules. While most plants and microorganisms can produce all the amino acids they need, tryptophan is one of eight amino acids that cannot be produced by animals.
The synthesis of tryptophan is one of the most complicated of all amino acids in the human diet. The overall pathway for the biosynthesis of tryptophan from chorismate can be viewed here.
Tryptophan is the least abundant of the essential amino acids. However, it is also one of the most crucial, as it is involved in the formulation of niacin and the neurotransmitter serotonin. Serotonin is crucial for regulation of mood and appetite; as well, since it is necessary for the production of the hormone melatonin, it is necessary for regulation of the sleep cycle.
Serotonin is produced from tryptophan in a two-step process, with the molecule 5-hydroxytryptophan as an intermediate step.
The compound 5-hydroxytryptophan can be extracted from natural sources as well as synthesized from tryptophan; as a result of the controversy surrounding tryptophan, it has been offered as an alternative to tryptophan supplements.
These molecules and reactions were drawn using ACD/ChemSketch, available for free download.