This document discusses vitamins, including their classification and properties. It covers fat-soluble vitamins A, D, E, and K. Vitamin A is important for vision and is obtained from beta-carotene. Vitamin D is unique in that it can be synthesized in skin upon sun exposure. Vitamin E acts as an antioxidant. Vitamin K is required for blood clotting and exists in forms K1 and K2. The document provides details on the structures, sources, and biological roles of these essential vitamins.

1. Vitamins

2. Prepared by
Dr. N.GOPINATHAN
ASSISTANT PROFESSOR
DEPARTMENT OF PHARMACEUTICAL CHEMISTRY
FACULTY OF PHARMACY
SRIHER [DU]
CHENNAI-116
TAMILNADU

3. Introduction
• It is essential dietary factors necessary for life.
• It was coined by funk in 1912.
• Latin vita - life

4. • In case of anti- beriberi- It is required in
very small amount but the absence result
in deficiency disease.
• It cannot be synthesized in the body but
it must be supplied.
• Exception Vitamin D . It is produced in
skin through UV irradiation of sterol.
Introduction

5. Classification

6. • It can take part in the oxidation – reduction
reaction.
• It forms part of various coenzyme.[It is non-
protein organic molecule required for catalytic
action of enzyme].
• The enzyme –coenzyme complex called
holoenzyme exhibit enzyme activity.
• Removal of coenzyme moeity gives
epoenzymewhich lacks enzyme activity
Introduction

8. Coenzyme

9. Fat soluble vitamins

10. VITAMIN A

11. Vitamin consist of
•Vitamin A1
•Vitamin A2
•Neovitamin A-α
•Neovitamin A-β

12. Vitamin A1

13. Vitamin A2

14. -β-carotene

15. • It is potent provitamin A.
• Structure of vitamin A1 was established
by karrer.
• Empirical formula of vitamin A1 was
C20H30O

16. On catalytic hydrogenation give perhydro
vitamin A1 shows the presence of 5 double
bond in vitamin A1.

17. Reaction with P-nitro benzoic acid
gave ester indicating the presence of
OH

18. Ozonolysis

19. Ozonolysis of vit A1 yield geranic acid
shows the presence of β ionone
nucleus.

20. Oxidation of vit.A1 with KMnO4 give
acetic acid.
This indicates the presence of methyl
group attached to the double bonds in
the molecule.

21. Biogenesis
• An oxygenase located in the intestinal mucosa
is believed to cleave the provitamin A to β
carotene, centrally.
• This yield two moles of retinal which is acted
upon by alcohol dehydrogenase giving retinol.
• All the trans configuration of the double bond
in β carotene is retained in retinal and retinol.

23. Rhodopsin cycle
• Retinol and retinal serve as reactant causing
chemical changes that occur during the visual
process in rods of eye.
• Two types of light receptors in retina
• The rods for vision in dim light.
• The cones for colour vision and vision in bright
light.
• The rod visions are discussed here

24. • Retinol is present as ester in the rods.
• It is oxidised here by a specific retinl
dehydrogenase to all trans retinal, which
is isomerised to 11 cis retinal
• 11 cis retinal combines with an opsin –
phospholipid complex to form an light
sensitive rhodopsin . [visual purple]

25. • When the retina is illuminated ,
rhodopsin is bleached.
• This bleaching results in the
isomerisation of the 11 -cis retinal to
11- trans retinal and regeneration of
opsin – phospholipid complex.

28. VITAMIN E

29. Introduction
• It is a group of fat soluble compound
collectively called tocopherols
• Greek Tokos- child birth phero-to bear
• It is required by many species for normal
reproduction
• α,β, ζ, δ, ε and η Tocopherols.

30. Tocopherol

31. • It is the richest source are wheat germ oil,
cotton seed oil, corn oil and palm oil.
• Fernholz established the chemical structure of
alpha tocopherol.
• Empirical formula is C29H50O2
• Formation of ether indicates the presence of
oH.[ free].

32. • Pyrolysis yield duroquinol
• The optically active lactone was shown to be
derived from gamma hydroxy acid
• Chromic acid oxidation yield dimethyl maleic
anhydride, lactone, C18 ketone and c16 acid.
It indicated the structure of aliphatic side
chain.

33. Structure of duroquinol

34. • Presence of chromn ring proved by controlled
oxidation with silver nitrate.
• It yield yellow quinine which was reduced to
quinol.
• The hydroxyl group shown tertiary nature in
oxidation and esterification reaction.
• Tertiary nature of OH ruled out coumarin
structure which yield secondary OH group.

35. Biological significance
• Anti oxidant activity
• It delays the oxidation of lipids to
lipid peroxide.
• Antioxidant s neutralise the free
radicals catalysing the peroxide
formation.

36. VITAMIN K

37. • It is a fat soluble methyl naphthaquinone
derivative.
• Vitamin K1 and K2 naturally occuring factor.
• Vitamin K1 – 7 isoprene units- yellow oil.
• Vitamin K2 – 6 isoprene units- yellow
crystalline solid

38. Menadione – referred as vitamin K
substitute exhibit Vitamin K activity

39. Vitamin K

40. • Vitamin K are thermo stable but sensitive to
alkali and light.
• Source : spinach and cabbage
• Karrer elucidated vitamin K1 structure.
• Empirical formula C31H46O
• On oxidation with excess chromic acid gave
phthalic acid this shows the absence of
substituent on the aromatic ring.
• Mild oxidation with chromic acid yield 14
naphthaquinone system.

41. Clinical signficace of vitamin k
• Role in blood clotting process
• It is observed that vitamin K deficiency result
in reduced concentration of protrombin.

42. VITAMIN D

43. • It is a fat soluble vitamin with antiricket
properties.
• Ergocalciferol D2 and cholecalciferol D3
• Cholecalciferol is natural vitamin.
• Ergocalciferol is synthetic derived by
irradiation of ergosterol.
• Vitamin D3 is more active than D2.
• It is found in fish liver oil.