D-alpha-Tocopheryl acetate

Description

D-alpha-tocopheryl acetate is a natural form of vitamin E and it is stable in terms of shelf life. It is probably the best form for people actively trying to prevent heart disease. It is used in the dietary and clinical supplementations.

References

[1] Jack Challem, User’s Guide to Nutritional Supplements, 2003
[2] M. K. Horwitt, Relative biological values of d-alpha-tocopheryl acetate and all-rac-alpha-tocopheryl acetate in man, The American Society for Clinical Nutrition, 1980, vol. 33, 1856-1860

Chemical Properties

off-white crystalline solid

Uses

Used in prevention and treatment of vitamin E deficiencies.

Uses

α-Tocopherol acetate is 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.

Uses

(+)-α-Tocopherol acetate has been used:

• as a component of growth medium for retinal cell lines
• as an external standard in high performance liquid chromatography (HPLC) to study its composition in leafy vegetables
• in the preparation of trans-resveratrol-encapsulated lipid nanocarriers (R-nano)

Definition

ChEBI: Alpha-Tocopherol acetate is a tocol.

General Description

Odorless off-white crystals. Darkens at 401° F.

Air & Water Reactions

D-alpha-Tocopheryl acetate may be sensitive to prolonged exposure to light and air. . Insoluble in water.

Reactivity Profile

An ester. Esters react with acids to liberate heat along with alcohols and acids. Strong oxidizing acids may cause a vigorous reaction that is sufficiently exothermic to ignite the reaction products. Heat is also generated by the interaction of esters with caustic solutions. Flammable hydrogen is generated by mixing esters with alkali metals and hydrides.

Fire Hazard

Flash point data for D-alpha-Tocopheryl acetate are not available. D-alpha-Tocopheryl acetate is probably combustible.

Biochem/physiol Actions

α-Tocopherol acetate or vitamin E-acetate has antioxidant properties and reduces lipid peroxidation. However, vitamin E acetate on pyrolysis leads to the generation of carcinogens like alkenes and benzenes.

Contact allergens

Tocopherol and tocopheryl acetate are used mainly as antioxidants. Tocopheryl acetate, an ester of tocopherol (vitamin E), can induce allergic contact dermatitis.

Safety Profile

When heated to decomposition it emits acrid smoke and irritating fumes.

Synthesis

A method of preparing vitamin E acetate, characterized in that it comprises the steps of:

(1) add 2,3,5-trimethylhydroquinone and catalyst composed of concentrated sulfuric acid, copper sulfate, tin chloride to the reaction solvent, stir until the material is dissolved, under the protection of N2, the temperature is controlled at 30-33C, isophytol is added dropwise in 3-3.5h, dropwise addition is completed, the temperature is raised to 62-66C, the reaction is held for 2.5h, the reaction is completed, the solution is divided, and the solvent is recovered by decompressed distillation, the reaction solution is Wash, extract vitamin E, deionized water washing until the solution pH is 7, wherein the mass ratio of isophytol to 2,3,5-trimethylhydroquinone is 2-2.5:1, the mass ratio of copper sulfate to 2,3,5-trimethylhydroquinone is 0.045-0.05:1, the mass ratio of stannic chloride to 2,3,5-trimethylhydroquinone is 0.006-0.012:1, the mass ratio of concentrated sulfuric acid to 2,3,5-trimethylhydroquinone is 0.006-0.012:1, the mass ratio of concentrated sulfuric acid to 2,3,5-trimethylhydroquinone is 0.006-0.012:1. 3,5-trimethylhydroquinone in a mass ratio of 0.2-0.4:1;

(2) to the vitamin E layer after washing in step (2) add acetic anhydride and sodium borohydride, N2 protection, heating to 126-130 C esterification reaction of 3.5h, the end of the reaction, decompression distillation recovery of acetic anhydride, water and 70-80% methanol cross-washing to the washout solution pH 7, washed twice, 50-60 C concentration under reduced pressure, recovery of petroleum ether, concentrated, to obtain acetate vitamin E, wherein, acetic anhydride with 70-80% methanol cross-washed to the washout solution pH 7, washed twice, 50-60 C concentrated under reduced pressure, recovery of petroleum ether, concentrated, to obtain acetate vitamin E. E, wherein the weight ratio of acetic anhydride to 2,3,5-trimethylhydroquinone is 2.3-2.7:1, and the amount of sodium borohydride added is 0.1-0.16% of the mass of acetic anhydride.