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Record Information
StatusDetected and Quantified
Creation Date2006-12-19 16:55:37 UTC
Update Date2019-07-23 05:46:58 UTC
Secondary Accession Numbers
  • HMDB05768
Metabolite Identification
Common NameKyotorphin
DescriptionKyotorphin (L-tyrosyl-L-arginine) is a neuroactive dipeptide which plays a role in pain regulation in the brain. It was first isolated from bovine brain by Japanese scientists in 1979. Kyotorphin was named for the site of its discovery, Kyoto, Japan and because of its morphine- (or endorphin-) like analgesic activity. Kyotorphin has an analgesic effect, but it does not interact with the opioid receptors. Instead, it acts by releasing an Met-enkephalin and stabilizing it from degradation. It may also possess properties of neuromediator/neuromodulator. It has been shown that kyotorphin is present in the human cerebrospinal fluid and that it is lower in patients with persistent pain.
Kyotorphin, 3H-labeled, (L-tyr-D-arg)-isomerHMDB
Kyotorphin, 3H-labeled, (L-tyr-L-arg)-isomerHMDB
Kyotorphin, (L-tyr-D-arg)-isomerHMDB
Kyotorphin, 14C-labeled, (L-tyr-L-arg)-isomerHMDB
Chemical FormulaC15H23N5O4
Average Molecular Weight337.3742
Monoisotopic Molecular Weight337.175004249
IUPAC Name(2S)-2-[(2S)-2-amino-3-(4-hydroxyphenyl)propanamido]-5-carbamimidamidopentanoic acid
Traditional Nametyr-arg
CAS Registry Number70904-56-2
InChI Identifier
Chemical Taxonomy
Description belongs to the class of organic compounds known as peptides. Peptides are compounds containing an amide derived from two or more amino carboxylic acid molecules (the same or different) by formation of a covalent bond from the carbonyl carbon of one to the nitrogen atom of another.
KingdomOrganic compounds
Super ClassOrganic acids and derivatives
ClassCarboxylic acids and derivatives
Sub ClassAmino acids, peptides, and analogues
Direct ParentPeptides
Alternative Parents
  • Alpha peptide
  • Arginine or derivatives
  • N-acyl-alpha-amino acid
  • N-acyl-alpha amino acid or derivatives
  • Alpha-amino acid or derivatives
  • Amphetamine or derivatives
  • 1-hydroxy-2-unsubstituted benzenoid
  • Aralkylamine
  • Phenol
  • Monocyclic benzene moiety
  • Benzenoid
  • Amino acid or derivatives
  • Amino acid
  • Guanidine
  • Carboximidic acid
  • Carboximidic acid derivative
  • Carboxylic acid
  • Monocarboxylic acid or derivatives
  • Organic 1,3-dipolar compound
  • Propargyl-type 1,3-dipolar organic compound
  • Carboximidamide
  • Primary aliphatic amine
  • Imine
  • Hydrocarbon derivative
  • Organic oxygen compound
  • Amine
  • Organic nitrogen compound
  • Organopnictogen compound
  • Organic oxide
  • Organonitrogen compound
  • Organooxygen compound
  • Carbonyl group
  • Primary amine
  • Aromatic homomonocyclic compound
Molecular FrameworkAromatic homomonocyclic compounds
External Descriptors

Biological location:


Physical Properties
Experimental Properties
Melting PointNot AvailableNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Predicted Properties
Water Solubility0.16 g/LALOGPS
pKa (Strongest Acidic)3.52ChemAxon
pKa (Strongest Basic)12.1ChemAxon
Physiological Charge1ChemAxon
Hydrogen Acceptor Count8ChemAxon
Hydrogen Donor Count7ChemAxon
Polar Surface Area174.55 ŲChemAxon
Rotatable Bond Count9ChemAxon
Refractivity97.82 m³·mol⁻¹ChemAxon
Polarizability35.31 ųChemAxon
Number of Rings1ChemAxon
Rule of FiveNoChemAxon
Ghose FilterNoChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Spectrum TypeDescriptionSplash KeyView
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-0gz9-1941000000-6442b8c85128732eba6bSpectrum
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-0002-1962000000-2d43882c73cd497c6d68Spectrum
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-004i-0911000000-6e5389102831f5caa24cSpectrum
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-002b-1970100000-a48c256e767df926766eSpectrum
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-0gz9-1942000000-38d408829fea36a689d3Spectrum
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-0036-2950000000-4264faca814a387d0378Spectrum
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-0gz9-1941000000-6442b8c85128732eba6bSpectrum
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-0002-1962000000-2d43882c73cd497c6d68Spectrum
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-004i-0911000000-6e5389102831f5caa24cSpectrum
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-002b-1970100000-a48c256e767df926766eSpectrum
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-0gz9-1942000000-38d408829fea36a689d3Spectrum
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-0036-2950000000-4264faca814a387d0378Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-000f-8930000000-af6fe7957f5d80691c77Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (2 TMS) - 70eV, Positivesplash10-01p9-4916000000-632209cfa0cbb1905d8cSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-000i-1839000000-de1c7c304ff61eaf0380Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-02br-1910000000-6fa1321f58e071355fc9Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0cdr-4900000000-10afb93f6d719b98c35aSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-000f-2097000000-11f084995e26e7d9938fSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-0a6u-5591000000-171a1e247f9f02ebea54Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-052f-9300000000-ffb902b320bf0e7f5043Spectrum
Biological Properties
Cellular LocationsNot Available
Biospecimen Locations
  • Cerebrospinal Fluid (CSF)
Tissue LocationsNot Available
Normal Concentrations
Cerebrospinal Fluid (CSF)Detected and Quantified0.00119 +/- 0.00051 uMNot SpecifiedNot SpecifiedNormal details
Abnormal Concentrations
Cerebrospinal Fluid (CSF)Detected and Quantified0.00024 +/- 0.00004 uMNot SpecifiedNot Specifiedpersistent pain details
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDNot Available
Phenol Explorer Compound IDNot Available
FoodDB IDFDB023758
KNApSAcK IDNot Available
Chemspider IDNot Available
KEGG Compound IDC02993
BioCyc IDNot Available
BiGG IDNot Available
Wikipedia LinkKyotorphin
METLIN IDNot Available
PubChem Compound123804
PDB IDNot Available
ChEBI ID17537
Food Biomarker OntologyNot Available
VMH IDNot Available
Synthesis ReferenceBergmann, Max; Zervas, Leonidas; du Vigneaud, Vincent. Rearrangements of peptide-like substances. XXVIII. Synthesis of peptides containing arginine: d-tyrosyl-d-arginine. Berichte der Deutschen Chemischen Gesellschaft [Abteilung] B: Abhandlungen (1929), 62B 1905-9.
Material Safety Data Sheet (MSDS)Not Available
General References
  1. Kee AJ, Smith RC: Addition of tyrosyl-arginine to parenteral nutrition is anabolic in unstressed rats. Nutrition. 2000 May;16(5):361-7. [PubMed:10793305 ]
  2. Schwarz A, Wandrey C, Steinke D, Kula MR: A two-step enzymatic synthesis of dipeptides. Biotechnol Bioeng. 1992 Jan 20;39(2):132-40. [PubMed:18600923 ]
  3. Kee AJ, Smith RC, Gross AS, Madsen DC, Rowe B: The effect of dipeptide structure on dipeptide and amino acid clearance in rats. Metabolism. 1994 Nov;43(11):1373-8. [PubMed:7968592 ]
  4. Kee AJ, Smith RC: Organ clearance of tyrosyl-arginine and its effect on amino acid metabolism in young sheep. Metabolism. 1993 Aug;42(8):958-66. [PubMed:8345819 ]