Compound monograph
L-Carnosine
Carnosine is the dipeptide β-alanyl-L-histidine. This record describes the free parent, with an uncapped amino end and a free carboxyl end.
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Identity & nomenclature
Carnosine is the dipeptide β-alanyl-L-histidine. This record describes the free parent, with an uncapped amino end and a free carboxyl end.
This record denotes the free parent containing L-histidine. D-carnosine, salts, metal complexes and substituted derivatives are distinct identities.
Canonical name: Carnosine.
Declared aliases and development codes: β-Alanyl-L-histidine.
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Molecular properties
| Molecular formula | C9H14N4O3 |
|---|---|
| Molecular mass | 226.236 Da |
| CAS Registry Number | 305-84-0 |
| PubChem CID | 439224 |
| UNII | 8HO6PVN24W |
| Three-letter sequence | β-Ala–His |
| Terminal groups | Free N-terminal amino group; Free C-terminal carboxyl group |
β-Ala is one β-alanine (3-aminopropanoic acid) unit, not α-alanine. Its carboxyl group forms the amide bond to the α-amino nitrogen of L-histidine at position 2. β-Alanine is achiral; His2 is L. No standard one-letter string encodes this nonstandard first unit.
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Structural characteristics
Barger and Tutin examined residue order by derivatization and hydrolysis. She et al. described synthesis using L-histidine, with chromatographic and mass-spectrometric product confirmation. The chain contains one inter-residue amide bond and no inter-residue ring closure.
Terminal features: Free N-terminal amino group, Free C-terminal carboxyl group.
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Molecular targets & mechanisms
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Analytical considerations
The formula and 226.236 Da average mass follow the parent structure with CIAAW 2024 abridged atomic weights. PubChem displays 226.23; that printed value differs by 0.006 Da. The source calculation convention is not established, and the displayed number is not substituted for the defined calculation.
What the studies reported
No verified findings are published for this record under Content Policy v1.
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Verified bibliography
Cited studies by type
The 2 papers this record cites, counted by the kind of work each reports. A count is the size of this record's selection, not of the research that exists, and says nothing about results, safety, effectiveness or approval.
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Reference 1
Carnosine, Constitution and Synthesis.Barger G, Tutin F
The Biochemical journal · 1918 · Journal Article
currentReference 2
Characterization of a new L-carnosine synthase mined from deep-sea sediment metagenome.She J, Fu L, Zheng X, Li J, Wang L, Yu B, Ju J
Microbial cell factories · 2022-06-27 · Journal Article
current
Study models of these references
What kind of experiment each cited paper reports, taken from its abstract unless marked. Not a summary of results.
| Reference | Study models |
|---|---|
| Barger G et al. 1918 | Chemical, structural or analytical study; no biological model reported |
| She J et al. 2022 | Study models reported: in vitro · from the abstract |
Record history
Published 2026-10-20.
No changes to this record's content have been recorded since publication.
Each entry names the parts of this record that changed on that date. Changes to links between records and to catalogue links are not listed. This history covers the tracked record fields; study findings are not listed here.
Cite this record: Purely Peptides Research Library. L-Carnosine. Published 2026-10-20. https://purelypeptides.org/research/compounds/carnosine/
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Methodology & citation verification
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