L-Alanine

A chiral alpha-amino acid with a methyl side chain.

Formula
C3H7NO2
Functional group
Amino acids
Molar mass
89.09 g/mol
Also known as
(2S)-2-aminopropanoic acid, alanine, (S)-Alanine, L-alpha-alanine, (S)-2-Aminopropanoic acid, L-2-Aminopropionic acid

Overview

A chiral alpha-amino acid with a methyl side chain.

Alanine illustrates how replacing one glycine hydrogen with a different group creates a stereogenic alpha carbon. Its amino and carboxyl groups respond to pH. The L label describes configuration relative to a reference convention; it does not by itself specify the sign of optical rotation.

Identifiers

Formula
C3H7NO2
Functional group
Amino acids
Molar mass
89.09 g/mol
Also known as
(2S)-2-aminopropanoic acid, alanine, (S)-Alanine, L-alpha-alanine, (S)-2-Aminopropanoic acid, L-2-Aminopropionic acid
Chemical identifiers
SMILES
C[C@@H](C(=O)O)N
InChI
InChI=1S/C3H7NO2/c1-2(4)3(5)6/h2H,4H2,1H3,(H,5,6)/t2-/m0/s1
PubChem CID
5950

Properties

Melting / decomposition
297 °C (decomposes)
Sublimation
250 °C (sublimes)
Density
1.432 g/cu cm at 22 °C
Water solubility
In water, 1.64X10+5 mg/L at 25 °C

Related compounds

  • Amino acids

    A chiral alpha-amino acid with a methyl side chain.

References

  1. PubChem Compound Summary: L-Alanine (CID 5950)National Center for Biotechnology Information · PubChem

    Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.

  2. OpenStax Organic Chemistry: Structures of amino acidsJohn McMurry · OpenStax · 2023

    Supports the qualitative structural interpretation of the recorded molecular structure; no new physical measurement or verified preparative yield is claimed.

  3. Hazardous Substances Data Bank (HSDB): L-Alanine — melting pointHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/5950#section=Melting-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Lide, D.R. CRC Handbook of Chemistry and Physics 86TH Edition 2005-2006. CRC Press, Taylor & Francis, Boca Raton, FL 2005, p. 3-10

  4. Hazardous Substances Data Bank (HSDB): L-Alanine — boiling pointHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/5950#section=Boiling-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Lide, D.R. CRC Handbook of Chemistry and Physics 86TH Edition 2005-2006. CRC Press, Taylor & Francis, Boca Raton, FL 2005, p. 3-10

  5. Hazardous Substances Data Bank (HSDB): L-Alanine — densityHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/5950#section=Density. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Lide, D.R. CRC Handbook of Chemistry and Physics 86TH Edition 2005-2006. CRC Press, Taylor & Francis, Boca Raton, FL 2005, p. 3-10

  6. Hazardous Substances Data Bank (HSDB): L-Alanine — solubilityHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/5950#section=Solubility. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Yalkowsky, S.H., He, Yan., Handbook of Aqueous Solubility Data: An Extensive Compilation of Aqueous Solubility Data for Organic Compounds Extracted from the AQUASOL dATAbASE. CRC Press LLC, Boca Raton, FL. 2003., p. 1992