"Tryptan" redirects here. For the type of anti-migraine drug, see
Triptan . For the hydrocarbon, see
Triptane .
l -Tryptophan
Names
IUPAC name
Tryptophan
Systematic IUPAC name
(2S )-2-amino-3-(1H -indol-3-yl)propanoic acid
Other names
2-Amino-3-(1H -indol-3-yl)propanoic acid
Identifiers
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard
100.000.723
KEGG
UNII
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
Y Key: QIVBCDIJIAJPQS-VIFPVBQESA-N
Y
c1[nH]c2ccccc2c1C[C@H](N)C(=O)O
Zwitterion : c1[nH]c2ccccc2c1C[C@H]([NH3+])C(=O)[O-]
Properties
C 11 H 12 N 2 O 2
Molar mass
204.229 g·mol−1
Soluble: 0.23 g/L at 0 °C,
11.4 g/L at 25 °C,
17.1 g/L at 50 °C,
27.95 g/L at 75 °C
Solubility
Soluble in hot alcohol, alkali hydroxides; insoluble in chloroform .
Acidity (pK a )
2.38 (carboxyl), 9.39 (amino)[ 2]
-132.0·10−6 cm3 /mol
Pharmacology
N06AX02 (WHO )
Supplementary data page
Tryptophan (data page)
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
Chemical compound
Tryptophan (symbol Trp or W )[ 3] is an α-amino acid that is used in the biosynthesis of proteins . Tryptophan contains an α -amino group, an α-carboxylic acid group, and a side chain indole , making it a polar molecule with a non-polar aromatic beta carbon substituent. Tryptophan is also a precursor to the neurotransmitter serotonin , the hormone melatonin , and vitamin B3 (niacin).[ 4] It is encoded by the codon UGG.
Like other amino acids, tryptophan is a zwitterion at physiological pH where the amino group is protonated (–NH+ 3 ; pKa = 9.39) and the carboxylic acid is deprotonated ( –COO− ; pKa = 2.38).[ 5]
Humans and many animals cannot synthesize tryptophan: they need to obtain it through their diet, making it an essential amino acid . In 2023, the emission spectrum of tryptophan was discovered in the interstellar gas of the star cluster IC 348 .[ 6]
Tryptophan is named after the digestive enzymes trypsin , which were used in its first isolation from casein proteins.[ 7] It was assigned the one-letter symbol W based on the double ring being visually suggestive to the bulky letter.[ 8]
^ a b Görbitz CH, Törnroos KW, Day GM (2012). "Single-crystal investigation of L-tryptophan with Z′ = 16". Acta Crystallogr. B . 68 (Pt 5): 549–557. doi :10.1107/S0108768112033484 . PMID 22992800 .
^ Dawson RM, et al. (1969). Data for Biochemical Research . Oxford: Clarendon Press. ISBN 0-19-855338-2 .
^
"Nomenclature and Symbolism for Amino Acids and Peptides" . IUPAC-IUB Joint Commission on Biochemical Nomenclature. 1983. Archived from the original on 2 December 2021. Retrieved 22 October 2022 .
^ Slominski A, Semak I, Pisarchik A, Sweatman T, Szczesniewski A, Wortsman J (2002). "Conversion of L-tryptophan to serotonin and melatonin in human melanoma cells" . FEBS Letters . 511 (1–3): 102–6. Bibcode :2002FEBSL.511..102S . doi :10.1016/s0014-5793(01)03319-1 . PMID 11821057 . S2CID 7820568 .
^ "L-tryptophan | C11H12N2O2 - PubChem" . pubchem.ncbi.nlm.nih.gov . Retrieved 22 December 2016 .
^ Iglesias-Groth S (August 2023). "A search for tryptophan in the gas of the IC 348 star cluster of the Perseus molecular cloud" . Monthly Notices of the Royal Astronomical Society . 523 (2): 2876–2886. Bibcode :2023MNRAS.523.2876I . doi :10.1093/mnras/stad1535 .
^ Curzon G (31 December 1987), Bender DA, Joseph MH, Kochen W, Steinhart H (eds.), "Hopkins and the Discovery of Tryptophan" , Progress in Tryptophan and Serotonin Research 1986 , Berlin, Boston: De Gruyter, pp. XXIX–XL, doi :10.1515/9783110854657-004 , ISBN 978-3-11-085465-7 , retrieved 19 February 2024
^ "IUPAC-IUB Commission on Biochemical Nomenclature A One-Letter Notation for Amino Acid Sequences" . Journal of Biological Chemistry . 243 (13): 3557–3559. 10 July 1968. doi :10.1016/S0021-9258(19)34176-6 .