Chemical substance record

Methionine

59-51-8C₅H₁₁NO₂S149.215 g/mol

Organic/Inorganic Small MoleculeChEBI source record

A sulfur-containing amino acid that is butyric acid bearing an amino substituent at position 2 and a methylthio substituent at position 4. — ChEBI

Safety references

Safety documents & references

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Identity & molecular properties

Source-linked values

CAS number	59-51-8	ChEBI ↗
Molecular formula	C₅H₁₁NO₂S	ChEBI ↗
Molar mass	149.215 g/mol	ChEBI ↗
Monoisotopic mass	149.05105 Da	ChEBI ↗
Formal charge	0	ChEBI ↗
ChEBI identifier	CHEBI:16811	ChEBI ↗

Cross-source molecular data

PubChem

Molar mass	149.21 g/mol	PubChem ↗
Exact mass	149.05104977 Da	PubChem ↗
Computed XLogP	-1.9	PubChem ↗
Topological polar surface area (Å²)	88.6	PubChem ↗
H-bond donors	2	PubChem ↗
H-bond acceptors	4	PubChem ↗
Rotatable bonds	4	PubChem ↗

PubChem computed values are shown separately from the ChEBI record. An exact InChIKey match was used to connect the records. Molecular descriptors do not describe a supplied product’s purity, particle size or performance.

Names & structural identifiers

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Source preferred name

methionine

IUPAC name

methionine

InChIKey

FFEARJCKVFRZRR-UHFFFAOYSA-N

SMILES

CSCCC(N)C(=O)O

InChI

InChI=1S/C5H11NO2S/c1-9-3-2-4(6)5(7)8/h4H,2-3,6H2,1H3,(H,7,8)

Classification & relationships

ChEBI ontology

sulfur-containing amino acidChEBI parent class · 26834 ↗alpha-amino acidChEBI parent class · 33704 ↗

carboxylic acid amino acid organosulfur compound organic molecular entity

Roles recorded in ChEBI

Saccharomyces cerevisiae metaboliteplant metaboliteEscherichia coli metaboliteDaphnia magna metabolitealgal metabolite

Database role annotations describe reported biological or chemical roles; they are not product approvals or recommendations for use.

Mass ↔ amount of substance

Calculated from sourced mass

Amount

Input unit

Equivalent amount

0.00670174 mol

Uses 149.215 g/mol from ChEBI. Assumes the substance described by this record; no purity or concentration correction is applied.

Elemental composition

Theoretical mass fractions

C

Carbon · 5 atoms

40.25%

S

Sulfur · 1 atom

21.49%

O

Oxygen · 2 atoms

21.44%

N

Nitrogen · 1 atom

9.39%

H

Hydrogen · 11 atoms

7.43%

Calculated theoretical mass fractions from the reported formula and PubChem periodic-table atomic masses. These are not assay or purity results.

Research & patent references

Selected source associations

The sulfur-containing amino acids: an overview. ↗The Journal of nutrition · 2006 Jun · PMID 16702333

A metabolomic strategy defines the regulation of lipid content and global metabolism by Δ9 desaturases in Caenorhabditis elegans. ↗BMC genomics · 2012 Jan 20 · PMID 22264337

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Sources & record history

Checked 27 Sep 2026

Identity, formula, mass, synonyms & ontologyEMBL-EBI ChEBI · CHEBI:16811

Release 255, 9 September 2026. ChEBI three-star (manually annotated) source entry. View original record ↗ · CC BY 4.0

Additional molecular descriptorsNCBI PubChem · CID 876 · retrieved 2026-09-27

PubCAS formats source data, connects references and computes explicitly labelled conversions. CAS cross-references are supplied by ChEBI; they do not constitute CAS verification or endorsement.

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