L-4-Hydroxy Proline


(2S,4R)-4-Hydroxypyrrolidine-2-carboxylic acid, Hyp, trans-4-Hydroxy-L-proline,
(2S,4R)-4-Hydroxyproline, L-hydroxyproline, hydroxyproline

Technical Data

CAS Number: 51-35-4
Molecular Formula: C5H9NO3
Molecular Weight: 131.13
Beilstein Registry Number: 81441
EC Number: 200-091-9

FabriChem Specifications

DescriptionWhite crystal or crystalline powder
Specific Rotation-74° to -77°
pH5.0 – 6.5
Chloride (Cl)0.0020% Max.
Ammonium (NH4)0.020% Max.
Sulfate (SO4)0.020% Max.
Heavy Metals10 ppm Max.
Iron (Fe)10 ppm Max.
Arsenic (As2O3)1 ppm Max.
Other Amino AcidsConforms
Loss on Drying0.20% Max.
Residue on Ignition0.10% Max.
Assay 98.5 – 101.0%

Molecular Structure



Hydroxy Proline is a common non-proteinogenic amino acid. Hydroxy Proline is produced by hydroxylation of the amino acid proline by the enzyme prolyl hydroxylase following protein synthesis.

Hydroxy Proline is a major component of the protein collagen. Hydroxy Proline and proline play key roles for collagen stability. Hydroxy Proline is found in few proteins other than collagen. For this reason, Hydroxy Proline content has been used as an indicator to determine collagen and/or gelatin amount.