Vitamin E Dr ARUN.pptx

1. VITAMIN E
Presented by
Dr Arun A
Subject : Chemistry of Natural
Products

2. INTRODUCTION
• Vitamin E was discovered in 1922 by Herbet Evans and Katherine
scott Bishop.
• In 1935 Evans and Glady isolated in a pure form and found out the
vitamin activity as a dietary fertility factor in rats.
• They named vitamin E as Tocopherol [Greek :tocos - childbirth] ,
[piro -to bear] and ol- ending signifies it status as a chemical alcohol.
• Alochol was capable to prevent reproductive failure in animals.
• The structure was elucidated by Paul Karrer (Nobel prize-1937).

3. VITAMIN E
• The word “vitamin” comes form the Latin word “vita”, means
“life”.
• Vitamins are organic compounds that are needed in
small amounts for the maintenance of normal metabolic
function.
• Vitamins are classified into two types, they are water soluble
vitamins and fat soluble vitamins.
• Vitamin E is a fat soluble vitamin.

4. VITAMIN E
• Vitamin E is an naturally occurring antioxidant (i.e., an
inhibitor of oxidation processes) in body tissues.
• It protects unsaturated fats in the body from oxidation
by peroxides and other free radicals.
• Vitamin E is also called as anti-sterility vitamin and
beauty vitamin.

5. CHEMISTRY 0F VITAMIN E
• The molecular formula is C₂₉H₅₀O₂.
• Vitamin E is a group of four tocopherols and four tocotrienols.
• Tocopherols are the derivatives of tocol ( 6-hydroxyl chromane ring )
with an isoprenoid side chain (3 units).
• About 8 tocopherols have been identified, they are alpha(α), beta(β),
gamma(γ), delta(δ), epsilon(ε), zeta1(ζ₁), zeta2(ζ₂) and eta (η).
• In tocotrienols there are 4 types they are alpha, beta, gamma and delta.
• They are named as ,β,γ and δ based on the number and position of the methyl
groups in the chromane ring .

6. CHEMISTRY OF VITAMIN E
• Tocol contains chromane ring with an alcoholic hydroxyl group (OH) at the 6th
position .
• OH group present at the chromane ring is responsible for the anti-oxidant activity of
vitamin E.
• The activity and stability of the compound increase with increase in the number of
methyl group attached to the chromane ring.
• Isoprenoid side chain ( 12 carbon aliphatic side chain with 2 methyl groups at the
middle and 2 methyl group at the end)at the 2nd position of the chromane ring.
Chromane Isoprenoid

7. GENERAL STRUCTURE

9. CHEMISTRY OF VITAMIN E
• There are four main forms of tocopherol.
• They are
α – tocopherol : 5,7,8 trimethyltocol
β – tocopherol : 5,8 dimethyltocol
γ – tocopherol : 7,8 dimethyltocol
δ – tocopherol : 8 methyltocol
• The alpha form has 3 methyl groups, the beta &
gamma form have 2 methyl groups and the delta
form has only 1 methyl group.
• α-tocopherol is most active and
predominant form of vitamin E

11. 3D FORM OF VITAMIN E

12. PHYSICAL PROPERTIES OF VITAMIN E
• Colour : Pale yellow
• State : Oil
• Solubility : Soluble in Fats and Organic solvents
Insoluble in water
• Stability : Thermostable and Chemostable
compound.
• Lipophilic in nature.

13. DIETARY SOURCE OF VITAMIN E
• Sunflower seeds
• Almonds
• Avocados
• Spinach
• Butternut Squash
• Kiwifruit
• Broccoli
• Trout
• Olive oil
• Shrimp

14. RECOMMENDED DIETARY ALLOWANCE OF VITAMIN E
• Recommended Dietary Allowance of Vitamin E is 10 mg/day. This available in a
normal diet.
: 4- 5 mg/day
: 8.3
mg/day
: 10
mg/day
• Infants
• Children
• Male
• Female : 8 mg/day
• Pregnancy : 10 mg/day
• Lactating women : 12 mg/day
• Requirement of vitamin E increases withincrease in the Poly Unsaturated Fatty Acid.
• Normal concentration in blood is 10mg/L.

15. BIOSYNTHESIS OF VITAMIN E

16. ABSORPTION, TRANSPORTION AND STORAGE
• Dietary vitamin E is absorbed in the
small intestine (duodenum) along with the
lipids.
• It is incorporated with chylomicrons, in
circulation these chylomicrons transport
vitamin E to the liver.
• It is stored in liver ,adipose tissue
and biological membranes.
• In liver vitamin E is incorporated into
Lipoprotiens LDL and VLDL and
then transported into the target tissues.

17. MECHANISM OF ACTION
• Free radicals, such as superoxide, hydroxyl ions and nitric oxide all contain an
unpaired electron.
• These radicals can have a negative effects on cells causing oxidative damage that
leads to cell death.
• Vitamin E prevent cell damage by binding to the free radical and neutralizing its
unpaired electron.
• Vitamin E (α-tocopherol) reacts with the lipid peroxide radicals formed by peroxidation
of polyunsaturated fatty acids , and it terminates the free radical chain reaction.

20. BIOCHEMICAL FUNCTIONS
• Biochemical functions of the vitamin E is based on its anti-oxidant property.
• Vitamin E acts as a scavenger and gets itself oxidized by free radical and
spares PUFA, and protects the polyunsaturated fatty acid from peroxidation
reactions.
• Vitamin E acts synergistically with Selenium, which is a cofactor of antioxidant
enzyme Glutathione peroxidase that destroy the free radicals.
• It protects RBC from hemolysis, occurs due to free radicals.
• It is essential for the membrane structure and integrity of the cell, hence it is
regarded as a membrane antioxidant.
• It prevents hepatic necrosis, by protecting the liver from damage by freeradicals.

21. BIOCHEMICAL FUNCTION
• Vitamin E inhibits the conversion of nitrites to nitrosamines, which are the cancer
promoters.
• It prevents the oxidation of vitamin A and C.
• It works with vitamin A , C and β-carotene to delay the onset of cataract.
• Vitamin E preserves and maintains germinal epithelium of gonads for proper
reproductive function, so it prevents sterility.
• It enhances the heme synthesis by enhancing the activity of aminolaevulinic acid
synthase and ALA dehydratase.
• It stabilize CoenzymeQ (Ubiquinone),which is required for cellular respiration
through electron transport chain.
• It may prevent or delay coronary heart disease by limiting the oxidation of LDL .

22. VITAMIN E DEFICIENCY
• Hemolytic anemia
• Myopathy(Muscular degeneration)
• Neuropathy(Neuronal degeneration)
• Retinopathy(Retinal degeneration)
• It can also cause a weakened immune system.
• It may cause an increased risk for hardening of the arteries (atherosclerosis), cancer, and
cataracts.
• Symptoms of vitamin E deficiency in newborn babies include:
Hemolytic anemia
Disease of the retina (retinopathy)

23. THERAPEUTIC USES OF VITAMIN E
❖Alzheimer’s Disease
❖Parkinson’s Disease
❖Atherosclerosis
❖Diabetes
❖Breast cancer
❖Traumatic brain injury
❖Pancreatic and skin cancers
❖Anti-ageing and UV protection.

24. REFERENCE
• go.drugbank.com/articles
• urmc.rochester.edu
• researchgate.net/publication
• britannica.com/science/vitamin-E
• pediatriconcall.com/drugs/vitamin-e
• U. Satyanarayana & U. Chakrapani-Biochemistry 4th Edition.
• MN Chatterjea & Rana Shinde –Textbook of Medical Biochemistry 8th Edition.

25. THANK
YOU