L-Histidine

L-Histidine - Names and Identifiers

Name	L-Histidine
Synonyms	His H-His-OH Histidine L-Histidine L-[+]-Histidine L-Histidine Base L-HISTIDINE BASE L-Histidine,free base (s)-1h-imidazole-4-alanin 3-(1h-imidazol-4-yl)-l-alanin (s)-1h-imidazole-4-propanoicaci 4-(2-Amino-2-carboxyethyl)imidazole (s)-4-(2-amino-2-carboxyethyl)imidazole (s)-alpha-amino-1h-imidazole-4-propanoicacid 1H-Imidazole-4-propanoic acid, alpha-amino-, (S)- (S)-2-Amino-3-(4-imidazolyl)propionic acid~H-His-OH
CAS	71-00-1
EINECS	200-745-3
InChI	InChI:1S/C6H9N3O2/c7-5(6(10)11)1-4-2-8-3-9-4/h2-3,5H,1,7H2,(H,8,9)(H,10,11)
InChIKey	HNDVDQJCIGZPNO-YFKPBYRVSA-N

L-Histidine - Physico-chemical Properties

Molecular Formula	C6H9N3O2
Molar Mass	155.15
Density	1.3092 (rough estimate)
Melting Point	282°C (dec.)(lit.)
Boling Point	278.95°C (rough estimate)
Specific Rotation(α)	12.4 º (c=11,6N HCl)
JECFA Number	1431
Water Solubility	41.6 g/L (25 ºC)
Solubility	Soluble in water (4.3g/100ml,25°C), extremely insoluble in ethanol, insoluble in ether.
Appearance	White crystal or crystalline powder
Color	White to off-white or pale yellow
Maximum wavelength(λmax)	['λ: 260 nm Amax: 0.05', , 'λ: 280 nm Amax: 0.05']
Merck	14,4720
BRN	4673585
pKa	1.8(at 25℃)
PH	7.0-8.0 (25℃, 0.1M in H2O)
Storage Condition	2-8°C
Stability	Stable. Incompatible with strong oxidizing agents.
Sensitive	Sensitive to light
Refractive Index	13 ° (C=11, 6mol/L H
MDL	MFCD00064315
Physical and Chemical Properties	Melting Point 282°C specific rotation 12.4 ° (c = 11,6N HCl) water-soluble 41.6g/L (25°C)
Use	Used as pharmaceutical raw materials and food additives

L-Histidine - Risk and Safety

Hazard Symbols	Xn - Harmful
Risk Codes	R22 - Harmful if swallowed R36/37/38 - Irritating to eyes, respiratory system and skin.
Safety Description	S24/25 - Avoid contact with skin and eyes. S36/37 - Wear suitable protective clothing and gloves. S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S22 - Do not breathe dust.
WGK Germany	2
RTECS	MS3070000
FLUKA BRAND F CODES	10-23
TSCA	Yes
HS Code	29332990
Toxicity	LD50 orally in Rabbit: > 5110 mg/kg

L-Histidine - Nature

Open Data Verified Data

This product is colorless needle-like or plate-like crystal. Odorless, slightly bitter. 227 degrees Celsius softening, 277 degrees Celsius decomposition. Soluble in water (7. 59%,25 ℃), extremely difficult to dissolve in alcohol, insoluble in ether. Its imidazole group is easy to form a complex salt with metal ions, and its hydrochloride is commonly used. In vivo by 5 Phosphoribosyl pyrophosphate (PRPP) and ATP ATP synthesis. It is a synthetic precursor of histamine, urinal acid, Carnosine and other biological substances.
It is a semi-essential amino acid, but it is essential for the growth and development of infants and young children. In patients with uremia, the supply of histidine is conducive to the full use of amino acids in patients. Long-term lack of histidine will appear negative nitrogen balance, skin damage, serum albumin decreased, especially hematocrit decreased. It is involved in the synthesis of hemoglobin in the role of blood.

Last Update：2024-01-02 23:10:35

L-Histidine - Preparation Method

Open Data Verified Data

hydrolysis the pig blood powder was hydrolyzed with hydrochloric acid at 110-115 ° C. For 24h, and the peptide chain of the pig blood powder globule protein was cleaved to generate free amino acids. The hydrolysate is filtered, diluted, and passed through a cation exchange column, and the various amino acid components are exchanged on the resin in a certain order. Then, under the action of the eluent, the amino acid is transferred from the resin phase to the solution phase, and L-histidine is concentrated and crystallized to obtain L-histidine. L-histidine can also be extracted from hydrolysates of defatted soybeans.
direct fermentation method.

Last Update：2022-01-01 11:10:19

L-Histidine - Use

Open Data Verified Data

amino acid drugs. The main components of amino acid infusion and comprehensive amino acid preparation. Usage and dosage for the treatment of gastric ulcer, anemia, allergy, etc. 5ml of 4% solution was injected subcutaneously or intramuscularly.
the food additive is used as a flavor enhancer and a nutritional supplement, and can be added to improve the flavor in the manufacture of bread, and is applied to infant food and post-operative patient food.

Last Update：2022-01-01 11:10:20

L-Histidine - Safety

Open Data Verified Data

low toxicity, adult toxic dose> 64g/d, adult daily intake of 32G can be tolerated for a short period of time; Mice, rats, oral LD50>15g/kg, subcutaneous LD50 >lOg/kg, rats intraperitoneal injection of LD50>8 g/kg; Mice, rats, intravenous injection of LD50>2g/kg.
light-shielding, closed and dry storage.

Last Update：2022-01-01 11:10:20

L-Histidine - Reference Information

FEMA	3694 \| L-HISTIDINE
pH range of acid-base indicator discoloration	7 - 8 at 15.5g/l at 25°C
NIST chemical information	information provided by: webbook.nist.gov (external link)
EPA chemical substance information	information provided by: ofmpeb.epa.gov (external link)
Introduction	the product form of L-histidine is white powder crystal. It is an important amino acid raw material, is a kind of human semi-essential amino acids, mainly used as amino acid infusion and oral amino acid preparation of raw materials; In addition, it is also the treatment of heart disease, anemia, rheumatoid arthritis, the important drugs such as peptic ulcer and solid hepatitis are widely used in the field of medicine.
trait	L-histidine is colorless needle-like or plate-like crystal, softened at 277 °c and decomposed at 287 °c. 25 ° C in water solubility of 41.9g/L, very slightly soluble in alcohol, insoluble in ether and chloroform. Sweet.
uses	uses of L-histidine: nutritional supplements, sweeteners. Purposes: used as a nutrition enhancer, is an amino acid infusion, an important component of compound amino acid preparations. Can be used to treat gastric ulcer. Also used in biochemical research. nutritional supplements. Essential components of amino acid infusion and comprehensive amino acid preparation. Medicine for the treatment of gastric ulcer, anemia, allergies, etc. It is used in biochemical research, and is used in medicine to treat gastric ulcer, anemia, allergy, etc. amino acid drugs. The main components of amino acid infusion and comprehensive amino acid preparation are used to treat gastric ulcer, anemia, angina pectoris, aortitis, cardiac insufficiency and other cardiovascular diseases. Adverse reactions and contraindications: low toxicity, adult toxic dose> 64g/day. Such as histamine hydrochloride injection of headache, flushing, heat. as a Nutrition Fortifier, it is an important component of amino acid infusion and compound amino acid preparation. Can be used to treat gastric ulcer. Also used in biochemical research. used as pharmaceutical raw materials and food additives
range of use	addition amount of L-histidine: according to national standards, the recommended dosage is 1‰ to 3.
content analysis	accurately weigh the sample pre-dried at 105 ℃ for 3H, after dissolving in 3ml formic acid and 50ml glacial acetic acid, titrate with 0.1mol/L perchloric acid and determine the end point by potentiometry. At the same time, the blank test was carried out and the necessary correction was made. Perchloric acid corresponds to 15.52mg of L-histidine (C6H9N3O2) per mL of 0.1mol/L.
toxicity	can be used safely in foods (FDA § 172.320,2000).
usage limit	accounts for 2.4% of the total protein in food (FDA § 172.320,2000). FEMA: baked goods, meat products, dairy products, candy, frosting, all 150mg/kg.
production method	extracted from pig blood and bovine blood. Blood Powder was prepared by spray drying of pig blood, about 18kg of blood powder per 100kg of pig blood. L-histidine is commonly used as its hydrochloride ([7048-02-4]). Concentrate the eluate containing L-histidine until crystallization occurs, adjust to pH 2.5 with hydrochloric acid while hot, immediately add ethanol twice the amount of the solution, stand, precipitate, filter, the crude L-histidine hydrochloride is obtained, which is decolorized, recrystallized and dried to obtain the finished product. L-histidine can also be extracted from hydrolysates of defatted soybeans. There are two main methods. One is a direct fermentation method, using glucose as a carbon source, and inducing drug-resistant strains of Corynebacterium Flavobacterium Corynebacterium glutamicum and the like by a direct fermentation method. The second is protein hydrolysis. The hydrolysis method is described in detail below. With Pig (cattle) blood meal or pig hair or hoof a as raw material, acid hydrolysis, and then separated and refined. Hydrolysis 50kg of pig blood powder and 4 times the amount of 6mol/L HCl were put into a hydrolysis tank, heated and maintained at 110-120 ° C., and subjected to hydrolysis for 24 hours. Preparation of upper column diluent the hydrolysate of the previous step was concentrated under reduced pressure, distilled water was added, and the acid was distilled off repeatedly for 3-4 times until the distillate was discharged without hydrochloric acid. Dilute the concentrated solution with distilled water to 500L, adjust the pH to 3.5-4 with concentrated ammonia water, add 20% of activated carbon to the Blood Powder, heat at 90 ℃, keep warm, stir, decolorize and filter for 6h while hot, the filtrate was allowed to stand overnight to precipitate, filtered, diluted to 2.5% with distilled water (based on the amount of blood powder), and adjusted to pH 2.5 with concentrated HCl to obtain the column diluent. Upper column separation, water washing, elution the above dilution on the column. 732 ×, PVC material, with 001 × 7 () strong acid styrene type cation exchange resin, 1730mm High, flow rate 1L/min, until L histidine appears in effluent, the upper column was stopped. Wash with water 500L, flow rate 1.5L/min. Collect the pH 7.0-10.0 fractions. After the collection is finished, recoil the resin with water for 15min, and then use 2 times the amount of HCl 1.5-2mol/L along the flow dynamic regeneration, the flow rate is 5-13L/min, it was then washed with water until pH 4. The eluent of histamine acid was refined, removed ammonia under reduced pressure, concentrated to dryness, then dissolved in 40L distilled water, adjusted to pH 3-3.2 with 6mol/L HCl, and 1kg activated carbon was added, heated at 90 ℃, stirred, decolorized for 30min, filter the residue while hot to take the filtrate, concentrate in a thin film evaporator, stand for 48h to precipitate crystals, filter to take crystals, wash with 95% ethanol, vacuum dry at 80 ℃ for 4H, L-histamine acid hydrochloride. The crude L-histamine acid monohydrochloride was obtained by refluxing dry flour and hydrochloric acid as raw materials for several hours, filtering and washing, and then treating with activated carbon to obtain a pure product after recrystallization and purification. From the basic amino acid fraction of the protein hydrolysate, it was obtained by separation with an ion exchange resin.
toxic substance data	information provided by: pubchem.ncbi.nlm.nih.gov (external link)