L-Histidine

155.15

155.15

4673585

200-745-3

4QD397987E

DTXSID9023126

C29597

Needles or plates|COLORLESS

29332990

92

-3.2

White to off-white or pale yellow powder

1.3092 (rough estimate)

287 °C (decomp)

278.95°C (rough estimate)

282ºC

1.731

H2O: 41.6 g/L (25 ºC)

Store at RT.

LD50 orally in Rabbit: > 5110 mg/kg

12.4 º (c=11,6N HCl)

Sweet

2.76(at 0 °C)

2.76 (at 0 °C)|pK1'= 1.78; pK2'= 5.97; pK3'= 8.97|pKa = 2.76 @ 0 °C

131.9 Ų [M+H]+ [CCS Type: DT, Method: single field calibrated with Agilent tune mix (Agilent)]|132.41 Ų [M+H]+ [CCS Type: DT, Method: stepped-field]|131.47 Ų [M-H]- [CCS Type: DT, Method: stepped-field]|127 Ų [M+H]+ [CCS Type: TW, Method: calibrated with polyalanine]|131.7 Ų [M+H]+ [CCS Type: DT, Method: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]|132.1 Ų [M+H]+ [CCS Type: DT, Method: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]|134.6 Ų [M+Na]+ [CCS Type: DT, Method: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]|134.8 Ų [M+Na]+ [CCS Type: DT, Method: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]|128.1 Ų [M-H]- [CCS Type: DT, Method: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]|128.5 Ų [M-H]- [CCS Type: DT, Method: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]|130.01 Ų [M-H]- [CCS Type: DT, Method: stepped-field]|132.74 Ų [M+H]+ [CCS Type: DT, Method: stepped-field]|135.48 Ų [M+Na]+ [CCS Type: DT, Method: stepped-field]|128.9 Ų [M-H]-

Softens @ 277 °C|Rhombic crystals (also forms a monohydrate) /L-histidine monohydrochloride/; rhombic crystals, isomorphous with the mono-HCl /L-histidine dihydrochloride/|UV: 11479 (Sadtler Research Laboratories Spectral Collection) /dl-Histidine/

2

22-36/37/38

24/25-36/37-26-22

MS3070000

Xn

Stable. Incompatible with strong oxidizing agents.

P261, P264, P270, P271, P280, P301+P312, P302+P352, P304+P312, P304+P340, P305+P351+P338, P312, P321, P330, P332+P313, P337+P313, P362, P501

H302+H332

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

L-Histidine is a food additive permitted for direct addition to food for human consumption, as long as 1) the quantity of the substance added to food does not exceed the amount reasonably required to accomplish its intended physical, nutritive, or other technical effect in food, and 2) any substance intended for use in or on food is of appropriate food grade and is prepared and handled as a food ingredient.

|Warning|H302+H332 (75%): Harmful if swallowed or if inhaled [Warning Acute toxicity, oral; acute toxicity, inhalation]|P261, P264, P270, P271, P280, P301+P312, P302+P352, P304+P312, P304+P340, P305+P351+P338, P312, P321, P330, P332+P313, P337+P313, P362, and P501|Aggregated GHS information provided by 335 companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

ORL-RAT LD50 > 15000 mg/kg, IPR-RAT LD50 > 8000 mg/kg, ORL-MUS LD50 > 15000 mg/kg, IVN-MUS LD50 > 2000 mg/kg; Mild gastrointestinal side effects.

WARFARIN ALONE AT 5 MG/KG OF BAIT KILLED 37% OF ROOF RATS, BUT WHEN IN COMBINATION WITH L-HISTIDINE (40 MG/KG BAIT), ACTIVATED CLAY, CHARCOAL, & CARBON (10 G/KG BAIT) IT CAUSED, RESPECTIVELY, 100, 88, 75, & 63% MORTALITY OF RATS.

The actions of supplemental L-histidine are entirely unclear. It may have some immunomodulatory as well as antioxidant activity. L-histidine may be indicated for use in some with rheumatoid arthritis. It is not indicated for treatment of anemia or uremia or for lowering serum cholesterol.|Parenteral nutrition|Supplementation of amino-acids where parenteral nutrition is required.

Is found abundantly in hemoglobin; has been used in the treatment of rheumatoid arthritis, allergic diseases, ulcers and anemia. A deficiency can cause poor hearing.

Absorbed from the small intestine via an active transport mechanism requiring the presence of sodium.|ESSENTIAL AMINO ACIDS ARE TRANSFERRED TO FETUS AGAINST A CONCN GRADIENT &, IN THE CASE OF HISTIDINE, NATURAL L-ISOMER HAS BEEN SHOWN TO CROSS SEVERAL TIMES AS FAST AS THE D-ISOMER.

PRODUCT OF OXIDATIVE DEAMINATION OR TRANSAMINATION OF L-HISTIDINE IS BETA-IMIDAZOLEPYRUVIC ACID; & PRODUCT OF DECARBOXYLATION IS HISTAMINE. HISTAMINE ENTERS OTHER PATHWAYS TO YIELD FURTHER METABOLIC PRODUCTS. /FROM TABLE/

Since the actions of supplemental L-histidine are unclear, any postulated mechanism is entirely speculative. However, some facts are known about L-histidine and some of its metabolites, such as histamine and trans-urocanic acid, which suggest that supplemental L-histidine may one day be shown to have immunomodulatory and/or antioxidant activities. Low free histidine has been found in the serum of some rheumatoid arthritis patients. Serum concentrations of other amino acids have been found to be normal in these patients. L-histidine is an excellent chelating agent for such metals as copper, iron and zinc. Copper and iron participate in a reaction (Fenton reaction) that generates potent reactive oxygen species that could be destructive to tissues, including joints.
L-histidine is the obligate precursor of histamine, which is produced via the decarboxylation of the amino acid. In experimental animals, tissue histamine levels increase as the amount of dietary L-histidine increases. It is likely that this would be the case in humans as well. Histamine is known to possess immunomodulatory and antioxidant activity. Suppressor T cells have H2 receptors, and histamine activates them. Promotion of suppressor T cell activity could be beneficial in rheumatoid arthritis. Further, histamine has been shown to down-regulate the production of reactive oxygen species in phagocytic cells, such as monocytes, by binding to the H2 receptors on these cells. Decreased reactive oxygen species production by phagocytes could play antioxidant, anti-inflammatory and immunomodulatory roles in such diseases as rheumatoid arthritis.
This latter mechanism is the rationale for the use of histamine itself in several clinical trials studying histamine for the treatment of certain types of cancer and viral diseases. In these trials, down-regulation by histamine of reactive oxygen species formation appears to inhibit the suppression of natural killer (NK) cells and cytotoxic T lymphocytes, allowing these cells to be more effective in attacking cancer cells and virally infected cells.

/SRP:/ Basic treatment: Establish a patent airway. Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with normal saline during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poison A and B/|/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in respiratory arrest. Positive pressure ventilation techniques with a bag valve mask device may be beneficial. Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start an IV with D5W /SRP: "To keep open", minimal flow rate/. Use lactated Ringer's if signs of hypovolemia are present. Watch for signs of fluid overload. Consider drug therapy for pulmonary edema ... . For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam (Valium) ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poison A and B/

Histidine

ECRISTIDINE; & LAROSTIDIN. /L-HISTIDINE MONOHYDROCHLORIDE/|Available commercially as L(+)-histidine hydrochloride and as the free base.|Found naturally in the L(-) form.

L-Histidine: ACTIVE

A SIMPLE & RAPID METHOD FOR SIMULTANEOUS DETERMINATION OF HISTAMINE & HISTIDINE IN FISH SAMPLES IS DESCRIBED. THE METHOD ENTAILS PAPER CHROMATOGRAPHY & IS SENSITIVE FROM 0.5 MUG TO AT LEAST 30 MUG.|MICROBIOLOGICAL ASSAY METHODS FOR HISTIDINE IN MATERIALS CONTAINING FREE FORM IN ABSENCE OF APPRECIABLE AMT OF PROTEIN.|CERTAIN BACTERIA, GROWN UNDER SUITABLE CONDITIONS, PRODUCE SPECIFIC L-AMINO ACID DECARBOXYLASE. CO2 PRODUCED BY THESE ENZYMES CAN BE MEASURED MANOMETRICALLY. CO2 PRODUCED DURING DECARBOXYLATION OF L-HISTIDINE TO YIELD HISTAMINE IS DETERMINED IN A WARBURG MANOMETER & IS A MEASURE OF THE AMINO ACID CONTENT IN THE SAMPLE.

L-HISTIDINE IS DETERMINED IN PLASMA & URINE BY COLORIMETRIC METHOD WITH FLUORODINITROBENZENE WHICH IS SUBSEQUENTLY DETERMINED SPECTROPHOTOMETRICALLY AT 400 NM.

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