ORN is found in 70 entries

ORN in polymers: 39 entries. Examples include: 1B2H, 1HTH, 1N0X

ORN as free ligands, exist in 31 entries. Examples include 1A9X, 1BXR, 1C30

Find related ligands: Stereoisomers Similar ligands Chemical Structure Search

View summary at Ligand Expo

Chemical Component Summary

Name L-ornithine
Identifiers (2S)-2,5-bis(azanyl)pentanoic acid
Formula C5 H12 N2 O2
Molecular Weight 132.16 g/mol
Type L-peptide linking
Isomeric SMILES NCCC[C@H](N)C(O)=O
InChI InChI=1S/C5H12N2O2/c6-3-1-2-4(7)5(8)9/h4H,1-3,6-7H2,(H,8,9)/t4-/m0/s1

Chemical Details

Formal Charge 0
Atom Count 21
Chiral Atom Count 1
Chiral Atoms CA
Bond Count 20
Aromatic Bond Count 0
Leaving Atoms OXT H2 HE2 HXT

Drug Info: DrugBank

DrugBank ID DB00129   (Stereoisomeric match)
Name L-Ornithine
  • approved
  • nutraceutical
Description Ornithine is an amino acid produced in the urea cycle by the splitting off of urea from arginine. It is a central part of the urea cycle, which allows for the disposal of excess nitrogen. L-Ornithine is a precursor of citrulline and arginine.
  • (S)-2,5-Diaminopentanoate
  • (S)-2,5-Diaminopentanoic acid
  • (S)-2,5-diaminovaleric acid
  • (S)-alpha,delta-Diaminovaleric acid
  • (S)-ornithine
  • (S)-α,δ-diaminovaleric acid
  • L-Ornithine
Brand Names
Affected Organism Humans and other mammals
Indication Used for nutritional supplementation, also for treating dietary shortage or imbalance. It has been claimed that ornithine improves athletic performance, has anabolic effects, has wound-healing effects, and is immuno-enhancing.
Pharmacology A non-essential and nonprotein amino acid, ornithine is critical for the production of the body's proteins, enzymes and muscle tissue. Ornithine plays a central role in the urea cycle and is important for the disposal of excess nitrogen (ammonia). Ornithine is the starting point for the synthesis of many polyamines such as putrescine and spermine. Ornithine supplements are claimed to enhance the release of growth hormone and to burn excess body fat. Ornithine is necessary for proper immune function and good liver function.
Mechanism of action L-Ornithine is metabolised to L-arginine. L-arginine stimulates the pituitary release of growth hormone. Burns or other injuries affect the state of L-arginine in tissues throughout the body. As De novo synthesis of L-arginine during these conditions is usually not sufficient for normal immune function, nor for normal protein synthesis, L-ornithine may have immunomodulatory and wound-healing activities under these conditions (by virtue of its metabolism to L-arginine).
  • Dietary Supplements
  • Micronutrients
  • Supplements
  • Non-Essential Amino Acids
CAS number 70-26-8
Drug Info/Drug Targets: DrugBank 3.0: a comprehensive resource for 'omics' research on drugs. Knox C, Law V, Jewison T, Liu P, Ly S, Frolkis A, Pon A, Banco K, Mak C, Neveu V, Djoumbou Y, Eisner R, Guo AC, Wishart DS. Nucleic Acids Res. 2011 Jan; 39 (Database issue):D1035-41. | PMID: 21059682