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Record Information
Creation Date2006-12-19 20:58:00 UTC
Update Date2017-03-02 21:28:01 UTC
Secondary Accession NumbersNone
Metabolite Identification
Common NameEndomorphin-2
DescriptionEndomorphin-1 (H-Tyr-Pro-Trp-Phe-NH2) and endomorphin-2 (H-Tyr-Pro-Phe-Phe-NH2) are peptide amides with the highest known affinity and specificity for the mu-opioid receptor.
Endomorphin 2HMDB
Chemical FormulaC32H37N5O5
Average Molecular Weight571.6667
Monoisotopic Molecular Weight571.279469319
IUPAC Name(2S)-2-{[(2S)-1-[(2S)-2-amino-3-(4-hydroxyphenyl)propanoyl]pyrrolidin-2-yl]formamido}-N-[(1S)-1-carbamoyl-2-phenylethyl]-3-phenylpropanamide
Traditional Name(2S)-2-{[(2S)-1-[(2S)-2-amino-3-(4-hydroxyphenyl)propanoyl]pyrrolidin-2-yl]formamido}-N-[(1S)-1-carbamoyl-2-phenylethyl]-3-phenylpropanamide
CAS Registry Number141801-26-5
InChI Identifier
Chemical Taxonomy
DescriptionThis compound belongs to the class of chemical entities known as oligopeptides. These are organic compounds containing a sequence of between three and ten alpha-amino acids joined by peptide bonds.
KingdomChemical entities
Super ClassOrganic compounds
ClassOrganic acids and derivatives
Sub ClassCarboxylic acids and derivatives
Direct ParentOligopeptides
Alternative Parents
  • Alpha-oligopeptide
  • Phenylalanine or derivatives
  • Proline or derivatives
  • N-acyl-alpha amino acid or derivatives
  • Alpha-amino acid amide
  • N-substituted-alpha-amino acid
  • Alpha-amino acid or derivatives
  • Amphetamine or derivatives
  • Pyrrolidine carboxylic acid or derivatives
  • Pyrrolidine-2-carboxamide
  • N-acylpyrrolidine
  • 1-hydroxy-2-unsubstituted benzenoid
  • Phenol
  • Aralkylamine
  • Monocyclic benzene moiety
  • Fatty amide
  • Benzenoid
  • Fatty acyl
  • Pyrrolidine
  • Tertiary carboxylic acid amide
  • Amino acid or derivatives
  • Carboxamide group
  • Secondary carboxylic acid amide
  • Primary carboxylic acid amide
  • Organoheterocyclic compound
  • Azacycle
  • Organopnictogen compound
  • Primary aliphatic amine
  • Organic oxygen compound
  • Carbonyl group
  • Hydrocarbon derivative
  • Organic oxide
  • Organic nitrogen compound
  • Organonitrogen compound
  • Organooxygen compound
  • Amine
  • Primary amine
  • Aromatic heteromonocyclic compound
Molecular FrameworkAromatic heteromonocyclic compounds
External DescriptorsNot Available
StatusExpected but not Quantified
  • Endogenous
BiofunctionNot Available
ApplicationNot Available
Cellular locationsNot Available
Physical Properties
Experimental Properties
Melting Point130 - 131 °CNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Predicted Properties
Water Solubility0.0061 mg/mLALOGPS
pKa (Strongest Acidic)9.51ChemAxon
pKa (Strongest Basic)7.72ChemAxon
Physiological Charge1ChemAxon
Hydrogen Acceptor Count6ChemAxon
Hydrogen Donor Count5ChemAxon
Polar Surface Area167.85 Å2ChemAxon
Rotatable Bond Count12ChemAxon
Refractivity157.74 m3·mol-1ChemAxon
Polarizability61.25 Å3ChemAxon
Number of Rings4ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
SpectraNot Available
Biological Properties
Cellular LocationsNot Available
Biofluid LocationsNot Available
Tissue LocationNot Available
PathwaysNot Available
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDNot Available
DrugBank Metabolite IDNot Available
Phenol Explorer Compound IDNot Available
Phenol Explorer Metabolite IDNot Available
FoodDB IDFDB023764
KNApSAcK IDNot Available
Chemspider ID4470615
KEGG Compound IDNot Available
BioCyc IDNot Available
BiGG IDNot Available
Wikipedia LinkNot Available
NuGOwiki LinkHMDB05774
Metagene LinkHMDB05774
METLIN IDNot Available
PubChem Compound5311081
PDB IDNot Available
ChEBI ID297398
Synthesis ReferenceShimizu, Yoshiro; Takahashi, Motohiro; Fukumizu, Atsuko; Tsuda, Yuko; Bryant, Sharon D.; Lazarus, Lawrence H.; Okada, Yoshio. Synthesis of endomorphin analogs and studies on the structure-opioid receptor-binding activity relationship. Peptide Science (1999), Volume Date 1998, 35th 197-200.
Material Safety Data Sheet (MSDS)Download (PDF)
General References
  1. Yu Y, Cui Y, Wang X, Fan YZ, Liu J, Yan X, Wang R: Endomorphin1 and endomorphin2, endogenous potent inhibitors of electrical field stimulation (EFS)-induced cholinergic contractions of rat isolated bronchus. Peptides. 2006 Jul;27(7):1846-51. Epub 2006 Mar 27. [PubMed:16564113 ]
  2. Feng Y, Zhao QY, Chen Q, Wang R: Vasorelaxant responses to endomorphin1[psi] and endomorphin2[psi], analogues of endomorphins, in rat aorta rings. Pharmazie. 2005 Nov;60(11):851-5. [PubMed:16320949 ]
  3. Yu Y, Wang CL, Cui Y, Fan YZ, Liu J, Shao X, Liu HM, Wang R: C-terminal amide to alcohol conversion changes the cardiovascular effects of endomorphins in anesthetized rats. Peptides. 2006 Jan;27(1):136-43. Epub 2005 Sep 1. [PubMed:16139930 ]