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Record Information
StatusDetected and Quantified
Creation Date2006-08-12 19:50:22 UTC
Update Date2020-04-23 20:54:06 UTC
Secondary Accession Numbers
  • HMDB03374
Metabolite Identification
Common NameD-Ornithine
DescriptionD-Ornithine is an amino acid produced in the urea cycle by the splitting off of urea from arginine. Ornithine is one of the products of the action of the enzyme arginase on L-arginine, creating urea. Therefore, ornithine is a central part of the urea cycle, which allows for the disposal of excess nitrogen. D-Ornithine has been identified in the human placenta (PMID: 32033212 ).
(2R)-2,5-Diaminopentanoic acidHMDB
Chemical FormulaC5H12N2O2
Average Molecular Weight132.161
Monoisotopic Molecular Weight132.089877638
IUPAC Name(2R)-2,5-diaminopentanoic acid
Traditional NameL-(-)-ornithine
CAS Registry Number348-66-3
InChI Identifier
Chemical Taxonomy
Description belongs to the class of organic compounds known as d-alpha-amino acids. These are alpha amino acids which have the D-configuration of the alpha-carbon atom.
KingdomOrganic compounds
Super ClassOrganic acids and derivatives
ClassCarboxylic acids and derivatives
Sub ClassAmino acids, peptides, and analogues
Direct ParentD-alpha-amino acids
Alternative Parents
  • D-alpha-amino acid
  • Fatty acid
  • Amino acid
  • Carboxylic acid
  • Monocarboxylic acid or derivatives
  • Amine
  • Hydrocarbon derivative
  • Organic oxide
  • Organopnictogen compound
  • Primary amine
  • Organooxygen compound
  • Organonitrogen compound
  • Organic oxygen compound
  • Primary aliphatic amine
  • Organic nitrogen compound
  • Carbonyl group
  • Aliphatic acyclic compound
Molecular FrameworkAliphatic acyclic compounds
External Descriptors
Physiological effect

Health effect:


Route of exposure:


Biological location:


Naturally occurring process:

Physical Properties
Experimental Properties
Melting PointNot AvailableNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Predicted Properties
Water Solubility172 g/LALOGPS
pKa (Strongest Acidic)2.67ChemAxon
pKa (Strongest Basic)10.29ChemAxon
Physiological Charge1ChemAxon
Hydrogen Acceptor Count4ChemAxon
Hydrogen Donor Count3ChemAxon
Polar Surface Area89.34 ŲChemAxon
Rotatable Bond Count4ChemAxon
Refractivity33.21 m³·mol⁻¹ChemAxon
Polarizability13.74 ųChemAxon
Number of Rings0ChemAxon
Rule of FiveYesChemAxon
Ghose FilterNoChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Spectrum TypeDescriptionSplash KeyView
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-001u-9000000000-deb45bcb4280a1e67a8fSpectrum
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (1 TMS) - 70eV, Positivesplash10-0089-9300000000-bbfdea03043e52ad8a15Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , positivesplash10-00lr-3900000000-1b22374231fec22d1e20Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , positivesplash10-00di-9300000000-0ce9f8eaa9b98ad18d91Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , positivesplash10-00di-9000000000-45d863665ba8a53004f0Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , positivesplash10-00di-9000000000-b4769e364cb748464ebeSpectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , positivesplash10-00di-9000000000-aaadcea853770440853cSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-015i-7900000000-01f75740979c473383a0Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-00dr-9100000000-8f2f412b16c89d59e236Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-00dl-9000000000-a216a8d4439f992b205bSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-001i-1900000000-59329678720e6407d762Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-01qi-4900000000-8f53e4b8a940aa83cd3fSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-00di-9000000000-5cfb47a9082ed47a2fa1Spectrum
Biological Properties
Cellular Locations
  • Peroxisome
Biospecimen Locations
  • Blood
  • Feces
  • Saliva
Tissue Locations
  • Epidermis
  • Fibroblasts
  • Intestine
  • Liver
  • Placenta
  • Skeletal Muscle
  • Spleen
Normal Concentrations
BloodDetected and Quantified89.0 +/- 28.0 uMAdult (>18 years old)BothNormal details
SalivaDetected but not Quantified Adult (>18 years old)Male
SalivaDetected but not Quantified Adult (>18 years old)Male
SalivaDetected but not Quantified Adult (>18 years old)Male
SalivaDetected but not Quantified Adult (>18 years old)Male
SalivaDetected but not Quantified Adult (>18 years old)Male
SalivaDetected but not Quantified Adult (>18 years old)Male
SalivaDetected but not Quantified Adult (>18 years old)Male
SalivaDetected but not Quantified Adult (>18 years old)Male
SalivaDetected but not Quantified Adult (>18 years old)Male
SalivaDetected but not Quantified Adult (>18 years old)Male
Abnormal Concentrations
BloodDetected and Quantified62.0 +/- 28.0 uMAdult (>18 years old)Both
Short bowel syndrome
FecesDetected but not Quantified Adult (>18 years old)BothColorectal Cancer details
Associated Disorders and Diseases
Disease References
Short bowel syndrome
  1. Pita AM, Fernandez-Bustos A, Rodes M, Arranz JA, Fisac C, Virgili N, Soler J, Wakabayashi Y: Orotic aciduria and plasma urea cycle-related amino acid alterations in short bowel syndrome, evoked by an arginine-free diet. JPEN J Parenter Enteral Nutr. 2004 Sep-Oct;28(5):315-23. [PubMed:15449570 ]
Colorectal cancer
  1. Brown DG, Rao S, Weir TL, O'Malia J, Bazan M, Brown RJ, Ryan EP: Metabolomics and metabolic pathway networks from human colorectal cancers, adjacent mucosa, and stool. Cancer Metab. 2016 Jun 6;4:11. doi: 10.1186/s40170-016-0151-y. eCollection 2016. [PubMed:27275383 ]
Associated OMIM IDs
DrugBank IDNot Available
Phenol Explorer Compound IDNot Available
FooDB IDFDB023157
KNApSAcK IDNot Available
Chemspider ID64236
KEGG Compound IDC00515
BioCyc IDCPD-217
BiGG ID2263101
Wikipedia LinkOrnithine
PubChem Compound71082
PDB IDNot Available
ChEBI ID16176
Food Biomarker OntologyNot Available
Synthesis ReferenceFurui, Masakatsu; Takahashi, Eiji; Shibatani, Takeji. Microbial manufacture of D-amino acids from racemates. Jpn. Kokai Tokkyo Koho (1998), 13 pp.
Material Safety Data Sheet (MSDS)Download (PDF)
General References
  1. Deignan JL, Livesay JC, Yoo PK, Goodman SI, O'Brien WE, Iyer RK, Cederbaum SD, Grody WW: Ornithine deficiency in the arginase double knockout mouse. Mol Genet Metab. 2006 Sep-Oct;89(1-2):87-96. Epub 2006 Jun 5. [PubMed:16753325 ]
  2. Mayer UM: [Hyperornithinaemia in patients with retinal dystrophy]. Ophthalmologe. 2003 Jan;100(1):55-61. [PubMed:12557027 ]
  3. Filho JC, Bergstrom J, Stehle P, Furst P: Simultaneous measurements of free amino acid patterns of plasma, muscle and erythrocytes in healthy human subjects. Clin Nutr. 1997 Dec;16(6):299-305. [PubMed:16844612 ]
  4. Lauteala T, Mykkanen J, Sperandeo MP, Gasparini P, Savontaus ML, Simell O, Andria G, Sebastio G, Aula P: Genetic homogeneity of lysinuric protein intolerance. Eur J Hum Genet. 1998 Nov-Dec;6(6):612-5. [PubMed:9887380 ]
  5. Saito A, Noguchi Y, Yoshikawa T, Doi C, Fukuzawa K, Matsumoto A, Ito T, Tsuburaya A, Nagahara N: Gastrectomized patients are in a state of chronic protein malnutrition analyses of 23 amino acids. Hepatogastroenterology. 2001 Mar-Apr;48(38):585-9. [PubMed:11379360 ]
  6. Nefyodov LI, Uglyanitsa KN, Smirnov VY, Karavay AV, Brzosko W: Comparative evaluation of blood plasma and tumor tissue amino acid pool in radiation or neoadjuvant preoperative therapies of breast cancer with the antitumor drug Ukrain. Drugs Exp Clin Res. 2000;26(5-6):231-7. [PubMed:11345030 ]
  7. Rutten EP, Engelen MP, Schols AM, Deutz NE: Skeletal muscle glutamate metabolism in health and disease: state of the art. Curr Opin Clin Nutr Metab Care. 2005 Jan;8(1):41-51. [PubMed:15585999 ]
  8. Vella S, Steiner F, Schlumbom V, Zurbrugg R, Wiesmann UN, Schaffner T, Wermuth B: Mutation of ornithine transcarbamylase (H136R) in a girl with severe intermittent orotic aciduria but normal enzyme activity. J Inherit Metab Dis. 1997 Aug;20(4):517-24. [PubMed:9266387 ]
  9. Sela BA, Zlotnik J, Masos T, Yablonski G, Abraham F: [Gyrate atrophy of choroid and retina, and hyperornithinemia]. Harefuah. 2000 Jan 16;138(2):101-5, 175. [PubMed:10883069 ]
  10. Camacho JA, Rioseco-Camacho N, Andrade D, Porter J, Kong J: Cloning and characterization of human ORNT2: a second mitochondrial ornithine transporter that can rescue a defective ORNT1 in patients with the hyperornithinemia-hyperammonemia-homocitrullinuria syndrome, a urea cycle disorder. Mol Genet Metab. 2003 Aug;79(4):257-71. [PubMed:12948741 ]
  11. Monnier VM, Sell DR: Prevention and repair of protein damage by the Maillard reaction in vivo. Rejuvenation Res. 2006 Summer;9(2):264-73. [PubMed:16706654 ]
  12. Zhang X, Rimpilainen M, Hoffmann B, Simelyte E, Aho H, Toivanen P: Experimental chronic arthritis and granulomatous inflammation induced by bifidobacterium cell walls. Scand J Immunol. 2001 Jul-Aug;54(1-2):171-9. [PubMed:11439164 ]
  13. Jensen TG, Sullivan DM, Morgan RA, Taichman LB, Nussenblatt RB, Blaese RM, Csaky KG: Retrovirus-mediated gene transfer of ornithine-delta-aminotransferase into keratinocytes from gyrate atrophy patients. Hum Gene Ther. 1997 Nov 20;8(17):2125-32. [PubMed:9414260 ]
  14. Sell DR, Monnier VM: Ornithine is a novel amino acid and a marker of arginine damage by oxoaldehydes in senescent proteins. Ann N Y Acad Sci. 2005 Jun;1043:118-28. [PubMed:16037230 ]
  15. Gokmen SS, Aygit AC, Ayhan MS, Yorulmaz F, Gulen S: Significance of arginase and ornithine in malignant tumors of the human skin. J Lab Clin Med. 2001 May;137(5):340-4. [PubMed:11329531 ]
  16. Elshenawy S, Pinney SE, Stuart T, Doulias PT, Zura G, Parry S, Elovitz MA, Bennett MJ, Bansal A, Strauss JF 3rd, Ischiropoulos H, Simmons RA: The Metabolomic Signature of the Placenta in Spontaneous Preterm Birth. Int J Mol Sci. 2020 Feb 4;21(3). pii: ijms21031043. doi: 10.3390/ijms21031043. [PubMed:32033212 ]


General function:
Involved in D-amino-acid oxidase activity
Specific function:
Regulates the level of the neuromodulator D-serine in the brain. Has high activity towards D-DOPA and contributes to dopamine synthesis. Could act as a detoxifying agent which removes D-amino acids accumulated during aging. Acts on a variety of D-amino acids with a preference for those having small hydrophobic side chains followed by those bearing polar, aromatic, and basic groups. Does not act on acidic amino acids.
Gene Name:
Uniprot ID:
Molecular weight:
D-Ornithine + Water + Oxygen → 5-Amino-2-oxopentanoic acid + Ammonia + Hydrogen peroxidedetails