L-5-Hydroxytryptophan

Chemical properties

white to pale grey powder

The Uses of L-5-Hydroxytryptophan

A labelled metabolite of Tryptophan

The Uses of L-5-Hydroxytryptophan

5-Hydroxy-L-Tryptophan is a hydroxylated metabolite of L-Tryptophan

The Uses of L-5-Hydroxytryptophan

5-Hydroxy-L-tryptophan has been used:

• to inject experimental mice for serotonin detection
• as a precursor of 5-hydroxytryptamine and injected in pregnant mice and neonatal rats for vital neutral red staining of lung slices
• as a standard in citrate-acetate buffer for its use in high performance liquid chromatography (HPLC) analysis

Indications

For use as an antidepressant, appetite suppressant, and sleep aid.

Background

5-Hydroxytryptophan (5-HTP), also known as oxitriptan (INN), is a naturally occurring amino acid and metabolic intermediate in the synthesis of serotonin and melatonin. 5-HTP is sold over-the-counter in the United Kingdom, United States and Canada as a dietary supplement for use as an antidepressant, appetite suppressant, and sleep aid, and is also marketed in many European countries for the indication of major depression under trade names like Cincofarm, Levothym, Levotonine, Oxyfan, Telesol, Tript-OH, and Triptum. Several double-blind placebo-controlled clinical trials have demonstrated the effectiveness of 5-HTP in the treatment of depression, though a lack of high quality studies has been noted. More study is needed to determine efficacy in treating depression.

What are the applications of Application

5-Hydroxy-L-tryptophan is a serotonin precursor

Definition

ChEBI: 5-hydroxy-L-tryptophan is the L-enantiomer of 5-hydroxytryptophan. It has a role as a human metabolite, a plant metabolite and a mouse metabolite. It is a 5-hydroxytryptophan, a hydroxy-L-tryptophan and a non-proteinogenic L-alpha-amino acid. It is an enantiomer of a 5-hydroxy-D-tryptophan. It is a tautomer of a 5-hydroxy-L-tryptophan zwitterion.

General Description

Colorless to pale pink crystals.

Air & Water Reactions

L-5-Hydroxytryptophan is sensitive to air. Slightly water soluble .

Reactivity Profile

L-5-Hydroxytryptophan reacts with bases. .

Fire Hazard

Flash point data for L-5-Hydroxytryptophan are not available, however, L-5-Hydroxytryptophan is probably combustible.

Trade name

Levothym (Promonta Lundbeck, Germany), Lévotonine (Panpharma, France), Oxyfan (Coli, Italy), Tript-OH (Sigma- Tai, Italy).

Biochem/physiol Actions

Hydroxylation of L-tryptophan occurs in the brain during serotonin synthesis. This is a step that controls the production of serotonin and also yields 5-hydroxy-l-tryptophan (5-HTP) as a metabolite. Thus, consumption 5-HTP, increases the serotonin level, which might result in depression, lack of sleep and severe headache.

Pharmacokinetics

The psychoactive action of 5-HTP is thought to be due to increased serotonin production in central nervous system tissue.

Metabolism

5-Hydroxytryptophan is decarboxylated to serotonin (5-hydroxytryptamine or 5-HT) by the enzyme aromatic-L-amino-acid decarboxylase via a vitamin B6 dependent reaction in nervous tissue and in the liver.

Purification Methods

Likely impurities are 5-hydroxy-D-tryptophan and 5-benzyloxytryptophan. Crystallise 5-hydroxy-L-tryptophan under nitrogen from water by adding EtOH. Store it under nitrogen. Also dissolve it in the minimum volume of hot H2O (~0.7g in 4mL) under nitrogen (charcoal) and allowed it to crystallise at 5o. The picrolonate crystallises from H2O with m 184-186o(dec). [Greenstein & Winitz The Chemistry of the Amino Acids J. Wiley, Vol 3 p 2732-2737 1961, Morris & Armstrong J Org Chem 22 306 1957, Beilstein 22/14 V 278.]