Tìm theo
L-Histidine
Các tên gọi khác (12 ) :
  • (S)-4-(2-Amino-2-carboxyethyl)imidazole
  • (S)-a-Amino-1H-imidazole-4-propanoic acid
  • (S)-alpha-amino-1H-Imidazole-4-propanoic acid
  • (S)-alpha-Amino-1H-imidazole-4-propionic acid
  • (S)-α-amino-1H-Imidazole-4-propanoic acid
  • H
  • His
  • Histidine
  • L-(-)-Histidine
  • L-(−)-histidine
  • L-Histidin
  • L-Histidine
Thuốc Gốc
Small Molecule
CAS: 71-00-1
ĐG : Amend
CTHH: C6H9N3O2
PTK: 155.1546
An essential amino acid that is required for the production of histamine. [PubChem]
Nhận Dạng Quốc Tế & Đặc Tính Hóa Học
Công thức hóa học
Phân tử khối
155.1546
Monoisotopic mass
155.069476547
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)/t5-/m0/s1
InChI Key
InChIKey=HNDVDQJCIGZPNO-YFKPBYRVSA-N
IUPAC Name
(2S)-2-amino-3-(1H-imidazol-5-yl)propanoic acid
Traditional IUPAC Name
L-histidine
SMILES
N[C@@H](CC1=CN=CN1)C(O)=O
Độ tan chảy
287 dec °C
Độ hòa tan
4.56E+004 mg/L (at 25 °C)
logP
-3.32
logS
-0.53
pKa (strongest acidic)
1.85
pKa (Strongest Basic)
9.44
PSA
92 Å2
Refractivity
38.06 m3·mol-1
Polarizability
14.67 Å3
Rotatable Bond Count
3
H Bond Acceptor Count
4
H Bond Donor Count
3
Physiological Charge
0
Number of Rings
1
Bioavailability
1
Rule of Five
true
pKa
2.76 (at 0 °C)
Dược Lực Học : 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.
Cơ Chế Tác Dụng : An essential amino acid that is required for the production of histamine. [PubChem] 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.
Dược Động Học :
▧ Absorption :
Absorbed from the small intestine via an active transport mechanism requiring the presence of sodium.
Độc Tính : 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.
Chỉ Định : 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.
Liều Lượng & Cách Dùng : Capsule - Oral
Powder - Oral
Tablet - Oral
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