Comprehensive notes on lipids

3. Contents :
 Lipids
 Classification of lipids
 Properties of lipids
 Function of lipids
 Fixed oil
 Properties of fixed oil
 Uses of fixed oil

4. Lipids :
 Lipids are large and diverse group of naturally occurring organic
compounds, that are esters of long chain fatty acids with alcohol
or of closely related derivatives.
 Lipids are soluble in nonpolar solvents. Examples are:
 Ether.
 Chloroform.
 Acetone.
 Lipids are insoluble in water.

5. Cont….
 There is great structural variety among the lipids and comprise of
following:
 Fixed oil
 Fats
 Waxes

6. Cont…..
 Fixed oils and fats differ only according to their melting point and
chemically they belong to the same group, if substance is liquid at
15.5-16.5 C, it is called fixed oil and solid or semi solid at the
above temperature, it is called fat.
 All lipids are insoluble in water but soluble in organic solvents:
 Ether
 Benzene
 acetone

7. Classification of lipids :
 Based on structure, they can be classified in following major
groups.
 Simple lipids
 Compound/Complex lipids
 Derived lipids
 Steroid lipids
 Miscellaneous lipids

8. Cont…
 Simple lipids :
Esters of fatty acid with various alcohols.
Examples :
• Fats and Oils
• Waxes
 Compound/Complex lipids :
Esters of fatty acid with alcohol containing additional groups
such as phosphate, carbohydrates and proteins.
Examples :
• Phospholipids
• Glycolipids

9. Cont…
 Derived lipids :
These includes bi-products of metabolic processes like fatty acids,
glycerol, fatty aldehydes and ketone bodies.
 Steroid lipid :
Steroids are lipids because they are hydrophobic and insoluble in
water, but they do not resemble lipids.
Examples :
• Cholesterol
• Vit. D
• Bile acid

10. Cont…
 Miscellaneous lipids :
• Aliphatic hydrocarbons
• Carotenoids
• Terpenes
• Vit. E and K
• Glycerol ether

11. Functions of lipids
Energy storage:
 Lipids are used as long term energy storage in the form of
triglycerides ( adipose Tissues )
Energy Source:
 When oxidized, each gram of fat releases 9 kcal of energy, or
more then twice the energy released by 1 gm of carbohydrates.

12. Cont….
Cell Membrane Structural Component:
Phosphoglycerides, Sphingolipids and steroids make up the basic
structure of all cell membranes act as receptors, antigens and
membrane anchors for proteins therefore contributing their proper
functioning.
Essential Nutrients:
• Some lipids are essential nutrients like:
• Vitamin A ( for vision )
• Vitamin D ( for calcium metabolism )

13. Cont…..
 These are fat soluble, hydrophobic ( nonpolar ) or amphipathic (
have both polar and nonpolar regions ), greasy compounds
 Lipids are heterogeneous group of compounds include
 Fixed oil
 Fats
 Waxes
 Fat soluble vitamins ( A,D,E and K)
 Steroidal hormones

14. Fixed oil :
 Fixed oils are esters of glycerol with long chain fatty acids such
as oleic, palmitic and stearic acids.
 They are rich in calories and mostly present in the seeds of plants,
as reserve food.
 These are oils which are usually obtained from plants source (
vegetable oils ).
 They are called fixed oils because they leave greasy mark on
paper and can't be distilled without being decomposed.

15. Properties :
 They are non-irritant
 They leave a greasy mark on paper.
 They form soap with alkalies.
 They are odorless and tasteless.
 They are non-volatile.
 They yield glycerol and fatty acids on hydrolysis.

17. Uses
a) Pharmaceutically:
1) As Vehicle:
 Peanut oil and sesame oil are used as solvent in the preparation of
certain IM injections.
2) As Emollient:
 For ointments and creams. Example : Almond Oil.

18. b) Industrially:
They are used in manufacturing of:
 Detergents
 Cosmetics
 Paints
 Soaps
 Textile and leather industry

19. Fixed oils :
 Castor oil
 Cotton seed oil
 Peanut oil
 Sunflower oil
 Corn oil
 Coconut oil
 Almond oil
 Soybean oil
 Sesame oil

20. Castor oil
 Biological origin : Ricinus communis
 Family : Euphorbiaceae
 Part used : Oil obtained from seeds.
Constituents:
 Linoleic acid
 Stearic acid
 Oleic acid

21. Uses
 It is used as Emollient.
 It also has anti-inflammatory properties.
 It is used in the preparation of :
 Hair oils
 Cosmetic products
 It is used as lubricants in paints and varnishes.

23. Cotton seed oil :
 Biological Origin : Gossypium herbaceum
 Family : Malvaceae
 part used : Seed
 Constituents:
• Palmitic acid
• Oleic acid
• Stearic acid
• Myristic acid

24. Uses
 It is used as vehicle for injections.
 It is used in preparation of hydrogenated vegetable oils.
 It is used emollient.
 For Skin :
• moisturizing
• anti-aging
• anti-inflammatory

26. Olive oil :
 Biological oil : Olea europaea.
 Family : Oleaceae
 Part used : Oil obtained from fruits.
Constituents :
• Gadoleic acid
• Palmitoleic acid
• Stearic acid
• Lignoceric acids

27. Uses :
 Antioxidant content.
 Olive oil may help prevent premature signs of aging on the skin.
 Vitamin content.
 Antibacterial effects.
 Moisturizing effects.
 Moisturizer and after-sun treatment.
 Exfoliator.
 Eye-makeup remover.
 Face mask.

29. Sunflower oil :
 Biological origin : Helianthus annus
 Family : Compositae
 Part used : seeds
Constituents:
• Arachidic acids
• Linolenic acids
• Oleic acids
• Palmitic acid

30. Uses :
 It is consumed in preparation of vegetable ghee
 It is used in the preparation of water-proof material.
 It is used in treatment of atherosclerosis
 The oil is used as medicine.
 It is used for constipation and lowering "bad" LDL cholesterol.
 Some people apply sunflower oil directly to the skin for poorly
healing wounds, skin injuries, and arthritis; and as a massage oil.
 In foods, sunflower oil is used as a cooking oil.

32. Peanut Oil :
 Synonym : Arachis oil , Ground oil
 Botanical Origin : Arachis hypogaea
 Family : Fabaceae
 Part Used : Edible seeds
 Constituents :
• Oleic acid (46.8%)
• Linoleic acid (33.4%)
• Palmitic acid (10.0%)
• Stearic acid
• Arachidic acid
• Lignoceric acid

33. Uses :
 Peanut oil is used to make medicine.
 Peanut oil is used to lower cholesterol and prevent heart disease.
 It is also used to decrease appetite as an aid to weight loss.
 Some people use it to help prevent cancer.
 Peanut oil is sometimes applied directly to the skin for arthritis
and joint pain.
 Rectally, peanut oil is used in ointments and medicinal oils for
treating constipation.

35. References :
 Textbook of pharmacognosy and phytochemistry (2nd edition).
Biren Shah
A. K. Seth