DL-α-トコフェロール 化學(xué)特性,用途語,生産方法
外観
黃色～赤褐色, 澄明の液體
定義
本品は、ビタミンEであり、次の化學(xué)式で表される。
溶解性
水に不溶。エタノール, アセトンに可溶。エタノール及びアセトンに極めて溶けやすく、水にほとんど溶けない。
解説
α-トコフェロール(5,7,8-トリメチルトコール，)は淡黃色のやや粘ちゅうな液體．融點(diǎn)2.5～3.5 ℃，沸點(diǎn)200～220 ℃(13 Pa)．＋0.65°(エタノール)．ラセミ體はトリメチルヒドロキノンとフィトールとの縮合により合成される．抗不妊作用の原因は，抗酸化作用であることが明らかにされた．
用途
酸化防止剤、薬理研究用。
化粧品の成分用途
閉塞剤、皮膚コンディショニング剤、酸化防止剤、香料
効能
ビタミンE補(bǔ)充薬
使用上の注意
不活性ガス封入
化學(xué)的特性
1mg = 1.1 IU
使用
dl-α-Tocopherol is the racemic analog of α-Tocopherol (T526125), the most bioactive of the naturally occurring forms of Vitamin E. Richest sources are green vegetables, grains, and oils, particularly palm, safflower and sunflower oils.
dl-α-Tocopherol is an antioxidant that protects cell membrane lipids from oxidative damage.
調(diào)製方法
Naturally occurring tocopherols are obtained by the extraction or molecular distillation of steam distillates of vegetable oils; for example, alpha tocopherol occurs in concentrations of 0.1–0.3% in corn, rapeseed, soybean, sunflower, and wheat germ oils.Beta and gamma tocopherol are usually found in natural sources along with alpha tocopherol. Racemic synthetic tocopherols may be prepared by the condensation of the appropriate methylated hydroquinone with racemic isophytol.
一般的な説明
TGF-β3 (transforming growth factor-β3) belongs to the TGF β superfamily. The TGFβ3 gene is mapped to human chromosome 14q24.3
応用例（製薬）
Alpha tocopherol is primarily recognized as a source of vitamin E,
and the commercially available materials and specifications reflect
this purpose. While alpha tocopherol also exhibits antioxidant
properties, the beta, delta, and gamma tocopherols are considered
to be more effective as antioxidants.
Alpha-tocopherol is a highly lipophilic compound, and is an
excellent solvent for many poorly soluble drugs.Of widespread
regulatory acceptability, tocopherols are of value in oil- or fat-based
pharmaceutical products and are normally used in the concentration
range 0.001–0.05% v/v. There is frequently an optimum
concentration; thus the autoxidation of linoleic acid and methyl
linolenate is reduced at low concentrations of alpha tocopherol, and
is accelerated by higher concentrations. Antioxidant effectiveness
can be increased by the addition of oil-soluble synergists such as
lecithin and ascorbyl palmitate.
Alpha tocopherol may be used as an efficient plasticizer. It has
been used in the development of deformable liposomes as topical
formulations.
d-Alpha-tocopherol has also been used as a non-ionic surfactant
in oral and injectable formulations.
安全性
Tocopherols (vitamin E) occur in many food substances that are
consumed as part of the normal diet. The daily nutritional
requirement has not been clearly defined but is estimated to be
3.0–20.0 mg. Absorption from the gastrointestinal tract is dependent
upon normal pancreatic function and the presence of bile.
Tocopherols are widely distributed throughout the body, with some
ingested tocopherol metabolized in the liver; excretion of metabolites
is via the urine or bile. Individuals with vitamin E deficiency are
usually treated by oral administration of tocopherols, although
intramuscular and intravenous administration may sometimes be
used.
Tocopherols are well tolerated, although excessive oral intake
may cause headache, fatigue, weakness, digestive disturbance, and
nausea. Prolonged and intensive skin contact may lead to erythema
and contact dermatitis.
The use of tocopherols as antioxidants in pharmaceuticals and
food products is unlikely to pose any hazard to human health since
the daily intake from such uses is small compared with the intake of
naturally occurring tocopherols in the diet.
The WHO has set an acceptable daily intake of tocopherol used
as an antioxidant at 0.15–2.0 mg/kg body-weight.
貯蔵
Tocopherols are oxidized slowly by atmospheric oxygen and
rapidly by ferric and silver salts. Oxidation products include
tocopheroxide, tocopherylquinone, and tocopherylhydroquinone,
as well as dimers and trimers. Tocopherol esters are more stable to
oxidation than the free tocopherols but are in consequence less
effective antioxidants.
Tocopherols should be stored under an inert gas, in an airtight
container in a cool, dry place and protected from light.
純化方法
Dissolve dl--tocopherol in anhydrous MeOH (15mL/g) cool to -6o for 1hour, then chill in a Dry-ice/acetone bath; crystallisation is induced by scratching with a glass rod. The dl--acetate [52225-20-4] (see DL-vitamin E actetate below) is a viscous yellow liquid with m -7o, b 184o/0.01mm, 224o/0.3mm, d 4 20 0.953, n D 20 1.496. It is used as a standard for Vitamin E activity where the unit of activity is attained with 1mg of pure dl--acetate. [Friedrich “Vitamins” Water de Guyter Publ, Berlin 1988, Beilstein 17/4 V 168.]
不和合性
Tocopherols are incompatible with peroxides and metal ions,
especially iron, copper, and silver. Tocopherols may be absorbed
into plastic.
規(guī)制狀況(Regulatory Status)
GRAS listed. Accepted in Europe as a food additive. Included in the
FDA Inactive Ingredients Database (IV injections, powder, lyophilized
powder for liposomal suspension; oral capsules, tablets, and
topical preparations). Included in the Canadian List of Acceptable
Non-medicinal Ingredients. Included in nonparenteral medicines
licensed in the UK.
DL-α-トコフェロール 上流と下流の製品情報(bào)
原材料
準(zhǔn)備製品