Vitamin E (Molecule of the Month for February 1997)
Structures of Vitamins
Vitamins are substances that play an essential part in animal metabolic processes, but which the animals cannot synthesise. In their absence the animal develops certain deficiency diseases or other abnormal conditions. Vitamins are chemicals other than proteins, carbohydrates, fats and mineral salts that are essential constituents of the food of animals. Although certain animals can synthesise certain vitamins and all animals needing vitamin D can manufacture it from ergosterol in the presence of u.v. light, the precise mechanism of action of many vitamins is still poorly understood. Small amounts of vitamins are essential for the regulation of all bodily processes. With the exception of vitamin D, the human body cannot make its own vitamins, and some cannot be stored. Vitamins must therefore be obtained from a food on a daily basis. A person's diet must provide all the necessary vitamins.
Vitamin E is essential for fertility and reproduction. Deficiency in rats leads to absorption in the female and loss of fertility on the male. The vitamin is supposed to work as an antioxidant that protects the cells from attack by reactive form of oxygen and free radicals. It is also nvolved in red blood cell formation.
The structure is that of the tocopherols. These are methylated derivatives of tocol.
They are widely distributed in vegetable lipids and in the body fat of animals, though animals cannot synthesize them. They have vitamin E activity and can protect unsaturated lipids against oxidation. Four are found naturally:
- alpha - tocopherol, C29H50 O2 is 5,7,8,-trimethyltocol - strongest vitamin E activity.
- beta - tocopherol C28H48 O2 is 5,8,-trimethyltocol
- gamma - tocopherol C28H48 O2 is 7,8,-trimethyltocol
- delta - tocopherol C27H46 O2 is 8,-trimethyltocol
Formal Chemical Name (IUPAC)
Update by Karl Harrison
(Molecule of the Month for February 1997 )