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Record Information
StatusExpected but not Quantified
Creation Date2006-12-19 20:58:00 UTC
Update Date2017-12-07 01:55:29 UTC
Secondary Accession Numbers
  • HMDB05774
Metabolite Identification
Common NameEndomorphin-2
DescriptionEndomorphin-2, also known as tetrapeptide-15, belongs to the class of organic compounds known as oligopeptides. These are organic compounds containing a sequence of between three and ten alpha-amino acids joined by peptide bonds. Endomorphin-2 exists as a solid and is considered to be practically insoluble (in water) and relatively neutral.
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 organic compounds known as oligopeptides. These are organic compounds containing a sequence of between three and ten alpha-amino acids joined by peptide bonds.
KingdomOrganic compounds
Super ClassOrganic acids and derivatives
ClassCarboxylic acids and derivatives
Sub ClassAmino acids, peptides, and analogues
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


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 g/LALOGPS
pKa (Strongest Acidic)9.51ChemAxon
pKa (Strongest Basic)7.72ChemAxon
Physiological Charge1ChemAxon
Hydrogen Acceptor Count6ChemAxon
Hydrogen Donor Count5ChemAxon
Polar Surface Area167.85 ŲChemAxon
Rotatable Bond Count12ChemAxon
Refractivity157.74 m³·mol⁻¹ChemAxon
Polarizability61.25 ųChemAxon
Number of Rings4ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectrum TypeDescriptionSplash Key
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-01qi-7632920000-61c9c3747ad919a34c4dView in MoNA
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (1 TMS) - 70eV, Positivesplash10-0zfu-9443853000-b0f6cf2c32cb5ac7bccaView in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-0ab9-0532290000-d0fd32e7d5d368aa05e9View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-00yr-1942010000-5ab5f523355007c7035dView in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-00xr-5930000000-cd6666801968bdeee246View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-00di-0101190000-e9403040412cd1a9fc72View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-03di-2965550000-1bb3d8a636a7d6c56062View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-01ox-9741100000-f250d43c7be9e88c4b87View in MoNA
Biological Properties
Cellular LocationsNot Available
Biospecimen LocationsNot Available
Tissue LocationsNot Available
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDNot Available
Phenol Explorer Compound IDNot Available
FoodDB IDFDB023764
KNApSAcK IDNot Available
Chemspider ID4470615
KEGG Compound IDNot Available
BioCyc IDNot Available
BiGG IDNot Available
Wikipedia LinkEndomorphin-2
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 ]