DL-Histidine

Synonym(s):(S)-2-Amino-3-(4-imidazolyl)propionic acid;(±)-2-Amino-3-(4-imidazolyl)propionic acid;L-Histidine;NSC 137773

CAS NO.：4998-57-6
Empirical Formula: C6H9N3O2
Molecular Weight: 155.15
MDL number: MFCD00005208
EINECS: 225-660-9
SAFETY DATA SHEET (SDS)
Update Date: 2026-04-22 18:57:36

What is DL-Histidine?

Chemical properties

white to slightly yellow crystalline powder

The Uses of DL-Histidine

DL-Histidine has been used to study the fouling behaviour of polyethersulfone ultrafiltration membranes made with different PVP (polyvinylpyrrolidone).

The Uses of DL-Histidine

histidine is a skin-conditioning amino acid.

Definition

ChEBI: An alpha-amino acid that is propanoic acid bearing an amino substituent at position 2 and a 1H-imidazol-4-yl group at position 3.

Synthesis Reference(s)

Journal of the American Chemical Society, 67, p. 502, 1945 DOI: 10.1021/ja01219a513
Chemical and Pharmaceutical Bulletin, 35, p. 3447, 1987

Biochem/physiol Actions

L-Histidine is involved in the one-carbon unit metabolism. It is associated with protein methylation. L-Histidine is a part of hemoglobin structure and function. L-Histidine is a component of dipeptides with antioxidative property. Histidine serves as a precursor for the formation of histamine, which is associated with allergic responses. Urocanic acid, an immune response modulator in skin is also biosynthesised from histidine.

Properties of DL-Histidine

Melting point:	273 °C (dec.)(lit.)
Boiling point:	278.95°C (rough estimate)
Density	1.3092 (rough estimate)
refractive index	1.6500 (estimate)
storage temp.	Keep in dark place,Inert atmosphere,Room temperature
solubility	0.5 M HCl: soluble
form	powder to crystal
pka	1.8(at 25℃)
color	White to Almost white
Merck	14,4720
BRN	7800
CAS DataBase Reference	4998-57-6(CAS DataBase Reference)
EPA Substance Registry System	Histidine (4998-57-6)

Safety information for DL-Histidine

Signal word	Warning
Pictogram(s)	Exclamation Mark Irritant GHS07
GHS Hazard Statements	H315:Skin corrosion/irritation H319:Serious eye damage/eye irritation H335:Specific target organ toxicity, single exposure;Respiratory tract irritation
Precautionary Statement Codes	P261:Avoid breathing dust/fume/gas/mist/vapours/spray. P305+P351+P338:IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.