An essential amino acid
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L-Tryptophan

Item No. 29600

Product Insert (PDF)Safety Data Sheet (SDS) (PDF)
Technical Information
CAS Number
73-22-3
Synonyms
  • NSC 13119
  • (–)-Tryptophan
Molecular Formula
C11H12N2O2
Formula Weight
204.2
Purity
≥98%
Formulation (Request formulation change)
A crystalline solid
Solubility(Learn about Variance in Solubility)
PBS (pH 7.2): 1 mg/ml
λmax
220 nm
SMILES
N[C@H](C(O)=O)CC1=CNC2=CC=CC=C21
InChi Code
InChI=1S/C11H12N2O2/c12-9(11(14)15)5-7-6-13-10-4-2-1-3-8(7)10/h1-4,6,9,13H,5,12H2,(H,14,15)/t9-/m0/s1
InChi Key
QIVBCDIJIAJPQS-VIFPVBQESA-N
Shipping & Storage Information
Storage
-20°C
Shipping
Room temperature in continental US; may vary elsewhere
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    25 g

    $37

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    50 g

    $54

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    100 g

    $99

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    250 g

    $229

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    Product Description

    L-Tryptophan is an essential amino acid.1 It serves as a substrate for tryptophan hydroxylase (TPH), indoleamine-2,3-dioxygenase (IDO), and tryptophan-2,3-dioxygenase (TDO) for the biosynthesis of serotonin (5-HT; Item No. 14332) and kynurenine (Item No. 11305).2 L-Tryptophan is also metabolized by enteric bacteria expressing tryptophanase into indole, pyruvate, and ammonia.3 It increases 5-HT, 5-hydroxy-L-tryptophan (5-HTP; Item No. 20539), and 5-hydroxyindolacetic acid (5-HIAA; Item No. 22889) levels in the diencephalon of rats when administered at a dose of 300 mg/kg.4 L-Tryptophan decreases immobility time in the forced swim test in rats when administered at doses of 4 and 20 mg/kg per day for eight weeks.5

    WARNING This product is not for human or veterinary use.

    References & Product Citations
    Product Description References

    1. Richard, D.M., Dawes, M.A., Mathias, C.W., et al. L-Tryptophan: Basic metabolic functions, behavioral research and therapeutic indication. Int. J. Tryptophan Res. 2, 45-60 (2009).

    2. O'Mahony, S.M., Clarke, G., Borre, Y.E., et al. Serotonin, tryptophan metabolism and the brain-gut-microbiome axis. Behav. Brain Res. 277, 32-48 (2015).

    3. Wikoff, W.R., Anfora, A.T., Liu, J., et al. Metabolomics analysis reveals large effects of gut microflora on mammalian blood metabolites. Proc. Natl. Acad. Sci. USA 106(10), 3698-3703 (2009).

    4. Esteban, S., Nicolaus, C., Garmundi, A., et al. Effect of orally administered L-tryptophan on serotonin, melatonin, and the innate immune response in the rat. Mol. Cell Biochem. 267(1-2), 39-46 (2004).

    5. Ouakki, S., El Mrabet, F.Z., El Hessni, A., et al. Conversion of L-tryptophan into melatonin is the possible action pathway involved in the effect of L-tryptophan on antidepressant-related behavior in female rats: Analysis of the influence of treatment duration. J. Behav. Brain Sci. 3(4), 362-372 (2013).