用户名： 密   码：
注册 | 忘记密码？
药品详细

Vitamin E(维生素E)

化学结构式图
中文名
维生素E
英文名
Vitamin E
分子式
C29H50O2
化学名
(2R)-2,5,7,8-tetramethyl-2-[(4R,8R)-4,8,12-trimethyltridecyl]-3,4-dihydro-2H-1-benzopyran-6-ol
分子量
Average: 430.7061
Monoisotopic: 430.381080844
CAS号
59-02-9
ATC分类
A11H 未知
药物类型
small molecule
阶段
approved, nutraceutical
商品名
同义名
基本介绍

A generic descriptor for all tocopherols and tocotrienols that exhibit alpha-tocopherol activity. By virtue of the phenolic hydrogen on the 2H-1-benzopyran-6-ol nucleus, these compounds exhibit varying degree of antioxidant activity, depending on the site and number of methyl groups and the type of isoprenoids. [PubChem]

生产厂家
    封装厂家
    参考
    Synthesis Reference Not Available
    General Reference
    1. Iuliano L, Micheletta F, Maranghi M, Frati G, Diczfalusy U, Violi F: Bioavailability of vitamin E as function of food intake in healthy subjects: effects on plasma peroxide-scavenging activity and cholesterol-oxidation products. Arterioscler Thromb Vasc Biol. 2001 Oct;21(10):E34-7. Pubmed
    2. Miller ER 3rd, Pastor-Barriuso R, Dalal D, Riemersma RA, Appel LJ, Guallar E: Meta-analysis: high-dosage vitamin E supplementation may increase all-cause mortality. Ann Intern Med. 2005 Jan 4;142(1):37-46. Epub 2004 Nov 10. Pubmed
    3. Horwitt MK, Elliott WH, Kanjananggulpan P, Fitch CD: Serum concentrations of alpha-tocopherol after ingestion of various vitamin E preparations. Am J Clin Nutr. 1984 Aug;40(2):240-5. Pubmed
    4. Rumbold AR, Crowther CA, Haslam RR, Dekker GA, Robinson JS: Vitamins C and E and the risks of preeclampsia and perinatal complications. N Engl J Med. 2006 Apr 27;354(17):1796-806. Pubmed
    5. Poston L, Briley AL, Seed PT, Kelly FJ, Shennan AH: Vitamin C and vitamin E in pregnant women at risk for pre-eclampsia (VIP trial): randomised placebo-controlled trial. Lancet. 2006 Apr 8;367(9517):1145-54. Pubmed
    6. Linus Pauling Institute Link
    剂型
    规格
    化合物类型
    Type small molecule
    Classes
    • Tocopherols
    Substructures
    • Tocopherols
    • Hydroxy Compounds
    • Pyrans
    • Phenols and Derivatives
    • Ethers
    • Benzene and Derivatives
    • Hydroquinones
    • Methoxyphenols
    • Benzopyrans
    • Heterocyclic compounds
    • Aromatic compounds
    • Anisoles
    • Phenyl Esters
    适应症
    药理
    Indication Vitamin E, known for its antioxidant activities, is protective against cardiovascular disease and some forms of cancer and has also demonstrated immune-enhancing effects. It may be of limited benefit in some with asthma and rheumatoid arthritis. It may be helpful in some neurological diseases including Alzheimer's, some eye disorders including cataracts, and diabetes and premenstrual syndrome. It may also help protect skin from ultraviolet irradiation although claims that it reverses skin aging, enhances male fertility and exercise performance are poorly supported. It may help relieve some muscle cramps.
    Pharmacodynamics Vitamin E has antioxidant activity. It may also have anti-atherogenic, antithrombotic, anticoagulant, neuroprotective, antiviral, immunomodulatory, cell membrane-stabilizing and antiproliferative actions. Vitamin E is a collective term used to describe eight separate forms, the best-known form being alpha-tocopherol. Vitamin E is a fat-soluble vitamin and is an important antioxidant. It acts to protect cells against the effects of free radicals, which are potentially damaging by-products of the body's metabolism. Vitamin E is often used in skin creams and lotions because it is believed to play a role in encouraging skin healing and reducing scarring after injuries such as burns. There are three specific situations when a vitamin E deficiency is likely to occur. It is seen in persons who cannot absorb dietary fat, has been found in premature, very low birth weight infants (birth weights less than 1500 grams, or 3½ pounds), and is seen in individuals with rare disorders of fat metabolism. A vitamin E deficiency is usually characterized by neurological problems due to poor nerve conduction. Symptoms may include infertility, neuromuscular impairment, menstrual problems, miscarriage and uterine degradation. Preliminary research has led to a widely held belief that vitamin E may help prevent or delay coronary heart disease. Antioxidants such as vitamin E help protect against the damaging effects of free radicals, which may contribute to the development of chronic diseases such as cancer. It also protects other fat-soluble vitamins (A and B group vitamins) from destruction by oxygen. Low levels of vitamin E have been linked to increased incidence of breast and colon cancer.
    Mechanism of action Although all forms of Vitamin E exhibit antioxidant activity, it is known that the antioxidant activity of vitamin E is not sufficient to explain the vitamin's biological activity.
    Vitamin E's anti-atherogenic activity involves the inhibition of the oxidation of LDL and the accumulation of oxLDL in the arterial wall. It also appears to reduce oxLDL-induced apoptosis in human endothelial cells. Oxidation of LDL is a key early step in atherogenesis as it triggers a number of events which lead to the formation of atherosclerotic plaque. In addition, vitamin E inhibits protein kinase C (PKC) activity. PKC plays a role in smooth muscle cell proliferation, and, thus, the inhibition of PKC results in inhibition of smooth muscle cell proliferation, which is involved in atherogenesis.
    Vitamin E's antithrombotic and anticoagulant activities involves the downregulation of the expression of intracellular cell adhesion molecule(ICAM)-1 and vascular cell adhesion molecule(VCAM)-1 which lowers the adhesion of blood components to the endothelium. In addition, vitamin E upregulates the expression of cytosolic phospholipase A2 and cyclooxygenase (COX)-1 which in turn enhances the release of prostacyclin. Prostacyclin is a vasodilating factor and inhibitor of platelet aggregation and platelet release. It is also known that platelet aggregation is mediated by a mechanism involving the binding of fibrinogen to the glycoprotein IIb/IIIa (GPIIb/IIIa) complex of platelets. GPIIb/IIIa is the major membrane receptor protein that is key to the role of the platelet aggregation response. GPIIb is the alpha-subunit of this platelet membrane protein. Alpha-tocopherol downregulates GPIIb promoter activity which results in reduction of GPIIb protein expression and decreased platelet aggregation. Vitamin E has also been found in culture to decrease plasma production of thrombin, a protein which binds to platelets and induces aggregation. A metabolite of vitamin E called vitamin E quinone or alpha-tocopheryl quinone (TQ) is a potent anticoagulant. This metabolite inhibits vitamin K-dependent carboxylase, which is a major enzyme in the coagulation cascade.
    The neuroprotective effects of vitamin E are explained by its antioxidant effects. Many disorders of the nervous system are caused by oxidative stress. Vitamin E protects against this stress, thereby protecting the nervouse system.
    The immunomodulatory effects of Vitamin E have been demonstrated in vitro, where alpha-tocopherol increases mitogenic response of T lymphocytes from aged mice. The mechanism of this response by vitamin E is not well understood, however it has been suggested that vitamin E itself may have mitogenic activity independent of its antioxidant activity.
    Lastly, the mechanism of action of vitamin E's antiviral effects (primarily against HIV-1) involves its antioxidant activity. Vitamin E reduces oxidative stress, which is thought to contribute to HIV-1 pathogenesis, as well as to the pathogenesis of other viral infections. Vitamin E also affects membrane integrity and fluidity and, since HIV-1 is a membraned virus, altering membrane fluidity of HIV-1 may interfere with its ability to bind to cell-receptor sites, thus decreasing its infectivity.
    Absorption 50 to 80% absorbed from gastrointestinal tract.
    Volume of distribution Not Available
    Protein binding Bound to beta-lipoproteins in blood.
    Metabolism
    Hepatic.
    Route of elimination Not Available
    Half life Not Available
    Clearance Not Available
    Toxicity Not Available
    Affected organisms
    • Humans and other mammals
    Pathways Not Available
    理化性质
    Properties
    State liquid
    Experimental Properties
    Property Value Source
    melting point 3 °C PhysProp
    water solubility Insoluble in water, but water-dispersible. Not Available
    logP 10 Not Available
    Predicted Properties
    Property Value Source
    water solubility 7.04e-06 g/l ALOGPS
    logP 8.84 ALOGPS
    logP 10.51 ChemAxon
    logS -7.8 ALOGPS
    pKa (strongest acidic) 10.8 ChemAxon
    pKa (strongest basic) -4.9 ChemAxon
    physiological charge 0 ChemAxon
    hydrogen acceptor count 2 ChemAxon
    hydrogen donor count 1 ChemAxon
    polar surface area 29.46 ChemAxon
    rotatable bond count 12 ChemAxon
    refractivity 135.37 ChemAxon
    polarizability 55.29 ChemAxon
    药物相互作用
    Drug Interaction
    Amprenavir Increased serum levels of vitamin E
    Orlistat Orlistat may impair the absorption of vitamin E, a fat soluble vitamin. Oral vitamin E should be administered 2 hours prior to or post orlistat administration.
    食物相互作用
    Not Available

    返回 | 收藏