File:L-Ornithin2.svg · Wikimedia Commons · See Wikimedia Commons
L-ornithine
Sign in to saveAlso known as (S)-ornithine, (S)-alpha,delta-diaminovaleric acid, (2S)-2,5-diaminopentanoic acid, L-(-)-Ornithine, (S)-a,D-Diaminovaleric acid, (S)-a,D-Diaminovalerate, (+)-S-Ornithine, 5-Amino-L-Norvaline
Ornithine is a non-proteinogenic α-amino acid that plays a role in the urea cycle. It is not incorporated into proteins during translation. Ornithine is abnormally accumulated in the body in ornithine transcarbamylase deficiency, a disorder of the urea cycle. The moiety derived from ornithine is called ornithyl.
OverviewAI-generated
L-ornithine is a chemical compound with the formula C₅H₁₂N₂O₂. Its IUPAC name is (2S)-2,5-diaminopentanoate;hydron. The substance has a mass of 132.09 and a weight of 132.16. It possesses a charge of 0, with three hydrogen bond donors and four hydrogen bond acceptors. The topological polar surface area is 92.2.
The canonical SMILES representation for L-ornithine is C(CC(C(=O)O)N)CN, while its isomeric SMILES is NCCC[C@H](N)C(O)=O. The compound is associated with the NCI Thesaurus ID C29611 and the PubChem CID 88747248. Its InChIKey is AHLPHDHHMVZTML-BYPYZUCNSA-N.
L-ornithine is referenced by 859 other encyclopedia articles. A search on PubMed yields a count of 24057 entries for the query "L-ornithine". The subject is also categorized under "L-Ornithine" on Commons.
Synthesized by Vinony from 17 facts across 4 sources: Wikidata, PubMed, PubChem, Vinony graph. Generated from structured data (not the Wikipedia text) and checked against those facts — may still contain errors.
Chemical data
- Formula
- C5H12N2O2
- Molecular weight
- 132.16 g/mol
- IUPAC name
- (2S)-2,5-diaminopentanoate;hydron
- SMILES
- [H+].C(C[C@@H](C(=O)[O-])N)CN
- InChIKey
- AHLPHDHHMVZTML-BYPYZUCNSA-N
- Polar surface area
- 92.2 Ų
- H-bond donors
- 3
- H-bond acceptors
- 4
- Formal charge
- 0
via PubChem
Research
24,057 papers- Synergistic role of gut-microbial L-ornithine in enhancing ustekinumab efficacy for Crohn's disease.Cell metabolism · 2025
- L-ornithine L-aspartate in acute treatment of severe hepatic encephalopathy: A double-blind randomized controlled trial.Hepatology (Baltimore, Md.) · 2022
- L-Aspartate, L-Ornithine and L-Ornithine-L-Aspartate (LOLA) and Their Impact on Brain Energy Metabolism.Neurochemical research · 2020
- Safety assessment of L-ornithine oral intake in healthy subjects: a systematic review.Amino acids · 2025
- Solving doubts about L-ornithine L-aspartate for overt hepatic encephalopathy: Whom and how to treat.Hepatology (Baltimore, Md.) · 2018
via PubMed
~3 min read
Encyclopedic overview
9 sectionsContents
- Role in urea cycle
- Other reactions
- Research
- Exercise fatigue
- Weightlifting supplement
- Cirrhosis
- See also
- References
- External links
Ornithine is a non-proteinogenic α-amino acid that plays a role in the urea cycle. It is not incorporated into proteins during translation. Ornithine is abnormally accumulated in the body in ornithine transcarbamylase deficiency, a disorder of the urea cycle. The moiety derived from ornithine is called ornithyl.
==Role in urea cycle== L-Ornithine is one of the products of the action of the enzyme arginase on L-arginine, creating urea. Therefore, ornithine is a central component of the urea cycle, which enables the disposal of excess nitrogen. Ornithine itself is recycled and, in a sense, acts as a catalyst.
Excerpted from Wikipedia’s “L-ornithine” article, available under the CC BY-SA 4.0 licence.