Lipids definition and classification with examples

about lipids and their classification.

1. SEMINAR PRESENTATION
NAME:- HITARTHSINH.D.SOLANKI
EXAM NO.:- 249
SUBJECT:- Pharmacognosy
TOPIC:- LIPIDS: Definition and Classification with
examples

2. INTRODUCTION
Lipids constitute a broad group of naturally
occurring molecules which include waxes, fats,
sterols, fat-soluble vitamins, monoglycerides,
diglycerides, phospholipids and others.

3. What are lipids ?
•Lipids are insoluble organic compounds that consist
of fat and oil. The chemical composition of these
molecules includes hydrogen, carbon, and oxygen.
• They provide high energy and perform three
important biological functions in the body: to
provide structure to cell membranes, to store
energy, and to function as signaling molecules. The
classification of lipids includes phospholipids,
triacylglycerols, and sterols.

4. FIXED OILS
Fixed oils are esters of fatty acid with glycerol.

5. PROPERTIES
Non-irritant
Odorless
Tasteless
Non-volatile
Insoluble in water and soluble in organic solvents
Produce greasy mark on paper
Upon heating strongly, undergo decomposition
Upon hydrolysis, yield glycerol and fatty acid

6. CHEMISTRY
Fixed oils are esters of fatty acid with glycerol. These
May be;
•Monoglycerides
•Diglycerides
•Triglycerides

7. CLASSIFICATION
On the basis of their ability to absorb
oxygen from air;
•Drying oil
•Non-drying oil
•Semi-drying oil

8. Classification of Lipids

9. a) Drying oil
When exposed to air, undergo oxidation and form
tough and hard film. These are usually used in
paints and varnishes.
For example;
Linseed oil
These oils neither undergo oxidation nor form
tough and hard film.
For example;
Olive oil
b) Non -Drying oil

10. c) Semi-Drying oil
When exposed to air, undergo little bit oxidation
and form tough and thin film.
For example;
Cottonseed oil

11. METHODS OF OBTAINING FIXED OILS
Direct expression
Solvent extraction
Steam treatment + extraction

12. COTTONSEED OIL
Botanical origin:
Gossypium herbaceum
Family:
Malvaceae
Part used:
Seeds

13. Constituents:
Glycerides of;
•Linoleic acid
•Oleic acid
•Palmitic acid
•Stearic acid
•Arachidic acid
•Myristic acid
Uses:
Food
Emollient
Vehicle for injections
Preparation of hydrogenated vegetable
oils
Soap manufacture

14. Toxicity:
Occur due to intravenous administration of
cottonseed oil emulsion.
Acute toxicity includes following symptoms;
Fever
Pain in back or chest
Nausea
Vomiting
Headache
Tachycardia
Dizziness

15. chronic toxicity includes following symptoms;
GIT bleeding
Mild anemia
Defects in blood clotting
Treatment of toxicity:
IV hydrocortisone sodium succinate 50grams
Promethazine 50mg
Heparin (to aid clearance of fat from circulation)

16. LINSEED OIL
Botanical origin:
Linum usitatissimum
Family:
Linaceae
Part used:
Seeds

17. Constituents:
Glycerides of;
•Isolinoleic acid
•Linoleic acid
•Stearic acid
•Myristic acid
•Palmitic acid
Uses:
In veterinary medicine as Purgative

18. OLIVE OIL
Botanical origin:
Olea europaea
Family:
Oleaceae
Part used:
Ripe fruit

19. Constituents:
Glycerides of;
•Oleic acid
•Linoleic acid
•Stearic acid
•Arachidic acid
•Palmitic acid
Uses:
Laxative
Nutrient
Emollient
Demulcent

20. VOLATILE OILS VS FIXED OILS
Volatile oilsVolatile oils Fixed oilsFixed oils
Volatilize at room Volatilize at room
temperaturetemperature
Don't get volatiles at room Don't get volatiles at room
temperaturetemperature
Obtained by distillationObtained by distillationObtained by extractionObtained by extraction
Leave no spot after Leave no spot after
evaporationevaporation
After evaporation, do After evaporation, do
leave spotleave spot
Cannot be saponifiedCannot be saponified Can be saponifiedCan be saponified
Mixtures of oleoptenes Mixtures of oleoptenes
and stereoptenesand stereoptenes
Esters of fatty acid with Esters of fatty acid with
glycerolglycerol
High refractive indexHigh refractive index Low refractive indexLow refractive index

21. FATS VS FIXED OILS
FatsFats Fixed oilsFixed oils
Solid at room temperatureSolid at room temperatureLiquid at room Liquid at room
temperaturetemperature
Contain saturated Contain saturated
glycerides e.g. glyceryl glycerides e.g. glyceryl
stearatestearate
Contain unsaturated Contain unsaturated
glycerides e.g. glyceryl glycerides e.g. glyceryl
oleateoleate

22. Simple lipids are esters of fatty acid linked with various
alcohols.
Fats and oils (triglycerides, triacylglycerols)

These esters of fatty acid have glycerol, a trihydroxy
alcohol. Fat is solid at room temperature, while oil is in
liquid form.

1. Simple Lipids or Homolipids

23. Triglycerides are abundant and constitute about 98
percent of all dietary lipids. The rest consists of
cholesterol, its esters and phospholipids. Unlike
carbohydrates, which can be stored only for a short
time in the body, triglycerides are stored in the body in
large amounts as body fat, which can last for years.
An average man weighing about 70 kg, has at least 10
to 20 percent of his body weight in lipid, most of which
is triacylglycerol. This is found in adipose (fat) tissue, as
well as all other organs of the body. Body fat is a
reservoir of chemical energy.

24. Waxes
Waxes are long-chain saturated and unsaturated fatty
acid esters with monohydroxy alcohols, which have
high molecular weight.
Waxes are produced naturally by skin glands as a
protection, to keep it lubricated, pliable, and water-
proof. Wax also covers hair, feathers, and wool.
They are insoluble in water but soluble in most
organic solvents the esters and waxes are more
resistant to saponification
Examples :- i) vegetable:- seasel wax, caranuba
wax,japanwax,bayberry wax.
ii) Animal:- spermeceti,bees wax,wool fat

25. •Botanical origin:
Apis mellifeca
Apidae
Honey Combs
Mycricyl palmate, Cerotic
acid, Melissic acid.
• Family:
• Part used:
• Constituents:
Bees wax

26. •Uses:
•In preparation of ointments, plasters and
polishes.
•Hardening agent in preparation of candle,
moulds and in dental and electronic
industries.
•In cosmetics
•Ingredient in paraffin ointment I.P

27. Heterolipids are fatty acid esters with
alcohol and additional groups.
Phospholipids (phosphatids)

Phospholipids contain fatty acids, glycerol,
nitrogen bases, phosphoric acid, and
other substituents. They are most
abundant in cell membranes and serve as
structural components. They are not
stored in large quantities. As their name
implies, phospholipids contain
phosphorus in the form of phosphoric
acid groups. Their molecular structure is
polar, consisting of one hydrophilic head
group and two hydrophobic tails.
2.Compound Lipids orHeterolipids

28. Glycolipids (cerebrosides)

Glycolipids are fatty acids with carbohydrates and
nitrogen but without phosphoric acid. Glycolipids also
include some compounds like sulfolipids, gangliosides,
and sulfatids which are structurally-related.
These cerebrosides are important constituents of the
brain and other tissues. They consist of at least one
sugar unit, so they are also called glycosphingosides.
They are like phospholipids because they have a
hydrophobic region, with a polar region and two long
hydrocarbon tails. Like phospholipids, glycolipids form
lipid bilayers that are self-sealing and form the
structure of cellular membranes.

30. 3. Derived Lipids
These substances are derived by hydrolysis from
compound and simple lipids. These fatty acids include
alcohols, mono- and diglycerides, carotenoids, steroids,
and terpenes.
Steroids

The steroids are biological compounds that are some of
the most studied types of fat. They contain no fatty acids
and unlike fats, are nonsaponifiable (cannot be
hydrolyzed to yield soap).

31. Cholesterol
Cholesterol is a well-studied
lipid, because of its strong
correlation with the incidence
cardiovascular disease. It is an
important component of cell
membranes and plasma
lipoproteins, and is an
important precursor of many
biologically important
substances like bile acids and
steroid hormones. It is
abundant in nerve tissues and is
associated with gallstones.

32. •Dietary cholesterol is found in saturated fats of
animals (as butter and lard), but vegetable oils do
not contain cholesterol. Only a small portion of
your body cholesterol comes from the diet. Most
of it is produced in the body. Eating unsaturated
fatty acids from vegetable oil helps lower blood
cholesterol levels by reducing cholesterol
synthesis in the body. However, eating saturated
fats from animal fat elevates blood cholesterol
and triglycerides and reduce the ratio of your
good to bad cholesterol.

33. THANK YOU
•Reference :-
PHARMACOGNOSY.
•Author
:-C.K.KOKATE,A.P.PUROHIT,S.B
.GOKHALE.
•Publication :- NIRALI
PRAKASHAN.
•PAGE NO. :- 10.1 – 10.46.