Definition examples fatty acids classification nomenclature

1. Derived Lipids
 Definition
 Examples
 Fatty acids
 Definition
 Classification
 Nomenclature
 List the derived lipids of biological importance
 Fatty acids
 Glycerol

2. Derived lipids
“ Derivative obtained on hydrolysis of simple and
compound lipids and exhibit lipid characteristics”

3. Examples of Derived lipids
On hydrolysis of simple/compound fats yield
 Fatty acids (FA)
 Alcohol: High molecular weight , straight chain of
alcohol yield on wax hydrolysis
Examples:
Glycerol (Monoacylglycerol /Diglycerides, Glycerol)
Cholesterol

4. 1- Fatty Acid (FA)
“ Carboxylic acid with a long aliphatic chain(C4- C24)
• Occurs naturally as Triglycerides (TGs)

5. Types of Fatty Acids (FA)
a) Straight chain FA
b) Branched chain FA
c) Substituted FA
d) Cyclic FA
e) Eicosanoids

6. Straight Chain FA
Saturated FA
Unsaturated FA

7. Saturated FA
 Contains no double bonds.
 Formula: CnH2n+1 COOH
 Harmful: as it increases
Cholesterol level
TGs level
 Palmatic Acid

8. Saturated FA
Classify as
Lower fatty acids : FA having less than 10 carbon atoms
Higher fatty acids: FA having greater than 10 carbon
atoms

9. Example of Lower fatty acids
 Acetic acid CH3COOH
 Propionic acid C2H5COOH
 Butyric acid C3H7COOH
 Caproic acid C5H11COOH
Examples of higher fatty acids
 Palmatic acid C15H31COOH
 Stearic acid C17H35COOH

10. Unsaturated FA
 Contains 1 or more double bonds in a chain.
• Further classified on degree of unsaturation
• Monounsaturated FA
• Polyunsaturated FA

11. Monounsaturated FA
 Contains 1 double bond in a chain.
 Formula : CnH2n-1 COOH
 Present in all fats
Oleic Acid C17H33COOH

12. Polyunsaturated FA
 Contains more than 1 double bonds in a chain
 Examples are
 Linoleic acid series
 Linolenic acid series
 Arachidonic acid series
 Essential Fatty acid :
•Not synthesized by human body
•Must be taken in the diet

13. Linoleic acid series
Sources: Peanut oil, Corn oil, Soybean oil.
 Contains 2 double bonds
 Formula: CnH2n-3 COOH
C9—C10; C12—C13

14. Linolenic acid series:
 Source: Soybean oil, cod liver oil
contains 3 double bonds
 C9—C10; C12—C13 and C15—C16
 Formula: CnH2n-5 COOH
Linolenic acid

15. Arachidonic acid series
 Source : Animal fats such as liver fat
contains 4 double bonds
Formula: CnH2n-7 COOH
 Bonds at C5—C6; C8—C9; C11—C12; C14—C15

16. b) Branched chain FA
 Odd Carbon branched chain fatty acid
 Even Carbon branched chain fatty acid

17.  Odd Carbon branched chain fatty acid
Examples: Propionic acid (3:0)
Heptadecanoic acid (17:0)
Even Carbon branched chain fatty acid
•Examples:
•Palmitic acid (16:0)
•Oleic acid (18:0)
• Found in plant and animals
• Sebaceous glands: Sebum
• Phytanic acid : Butter

18. C-Substituted Fatty Acids
 One or more Hydrogen atom are replaced by
 Hydroxyl group OR
 Methyl group
 Cerebronic acid of brain glycolipids
 Ricinoleic acid in castor oil

19. d) Cyclic Fatty Acids:
 bears cyclic group
 Chaulmoogric acid (C18H32O2) obtained from
Chaulmoogra seeds
 Used for leprosy treatment
Chaulmoogric acid (C18H32O2)

20. E- Eicosanoids
Compounds derived from long chain polyenoic fatty acids
(20-C).
Examples: Prostaglandins, Thromboxanes, Leukotrienes etc
Most are produced from Arachidonic acid.
Considered "local hormones”

21. Examples of Eicosanoids
Prostaglandins
Prostacyclines
Thromboxanes
Leukotrienes
Lipoxins

22. Eicosanoid
Functions
Inflammation
Fever
Regulation of blood pressure
Blood viscosity
Male fertility
Female conception
Muscle contraction
Blood clotting
Tissue growth
Regulation of sleep/wake cycle
Asthma.

23. Nomenclature of Fatty acids

24. Nomenclature
• Saturated FA ends “ anoic “
• Example
• Octanoic acid
• Unsaturated FA ends “ enoic”
• Example
• Octadecenoic (oleic)

26. • Numbering from functional group (COOH)
α
β
ώ
Nomenclature of Fatty acids

27. No of Carbon atoms 18
No of double bonds 1
Position of double bond 9
CH3(CH2)7-CH=CH (CH2)7-COOH
Nomenclature of Fatty acids

28. No of Carbon atoms 18
No of double bonds 1
Position of double bond 9
Linoleic acid series: (18:2, 9,12)
Linolenic acid series : (18:3, 9,12,15)
Arachidonic acid series (20; 4, 5,8, 11,14)
Nomenclature of Fatty acids

29. Omega−3 fatty
Three types of omega−3 fatty acids involved in human
physiology are
• α-Linolenic acid (ALA) (18C and 3 double bonds)
• Eicosapentaenoic acid (EPA) (20C and 5 double bonds)
• Docosahexaenoic acid (DHA) (22C and 6 double bonds)

30. Nomenclature
Isomerism
2 types of isomerism found in unsaturated fatty acid
Geometric Isomerism
Positional Isomerism
Nomenclature of Fatty acids

31. Figure 5.5
Unsaturated fatty acids form two different shapes
Cis – Isomers
Trans – Isomers
Geometric Isomerism

32. Flow chart of lipid classification
Geometric

33. Cis- unsaturated fatty acids
Decreases total cholesterol and TGs level.
Increases HDL level

34. Nomenclature
Positional Isomerism
•Variation in the location of double bonds along
the unsaturated fatty acid

35. Essential Fatty Acid (EFA)
 Linoleic acid, Linolenic acid, Arachidonic acid
 Linoleic acid is the most important
 Arachidonic acid is also synthesized by Linoleic acid
 Arachidonic is the precursor for prostaglandins and
leukotrienes

36. Biomedical importance of EFA
 Structural element of tissues
 Structural element of gonads
 Synthesize of prostagladins
 Structural element of mitochondria
 Serum levels of cholesterol
Deficiency
 Growth retardation
 Skin lesions
 Fatty liver
 Kidney demage

37. Derived lipids
• Fatty Acids
• Alcohols
Alcohols contained in the lipid molecule includes
 Glycerol
 Sterol (Cholesterol)
 Higher alcohols

38. Glycerol
 Commonly called as “Glycerine”
 Colorless oily fluid with a sweetish taste
 Soluble in water and alcohol
 Trihydric alcohol, contains 3-OH groups
Propane-1,2,3-triol

39. Glycerol
Sources:
Exogenous : Directly absorbs from the gut (22%)
Endogenous : Breakdown of fats(lipolysis) in adipose tissues
Uses:
• Nutrient value : Glycerol is converted to glucose and
glycogen by process gluconeogenesis
• Glycerol therapy:
in Cerebrovascular disease reduces cerebral oedema

40. Unsaturated Alcohol
(a) Phytol
(b) Lycophyll
(c) Carotene
(d) Sphingosine or Sphingol

41. (a) Phytol (C20H40O):
 An acyclic diterpene alcohol
 Used for synthetic forms of vitamin E and K.
 A constituent of chlorophyll
 In ruminants, the gut fermentation of ingested plant materials
liberates phytol
 Converted to Phytanic acid and stored in fats.

42. (b) Lycophyll C40H56O2
• A polyunsaturated dihydroxy alcohol
• Occurs in tomatoes as a purple pigment

43. (c) Carotene (C40H56)
• Easily split in the body at the central point
of the chain
• to give two molecules of alcohol, vitamin A.

44. (d) Sphingosine or Sphingol
( C18H37NO2)
Unsaturated Amino alcohol
 Present as a constituent of
• Phospholipid (Sphingomyelin)
• Glycolipids

45. Steroids
 Steroid are often found in association with fats
 Cyclopentanoperhydrophenanthrene Nucleus:
ABC - Phenanthrene rings
D- Cyclopentane ring

46. Sterol
 Also known as Steroid alcohols
 Compound has one/more (-OH) group and no carboxyl group with cyclo
pentano perhydrophenanthrene ring
 Examples: Cholesterol, vitamin D, Bile acid, Sex hormones

47. Sterol
Types:
(a) Zoosterols (Animals Sterols)
• Cholesterol
Fungi
• Ergosterol is present in the cell membrane
(b) Phytosterols (Plants Sterols)
• Campesterol
• Sitosterol
• Stigmasterol

48. Cholesterol (C27H45OH)
Do not provide energy
Found in every cell in the body
 Brain, Nervous tissues (2%)
 Liver
 Skin
Sources:
 Butter
 Cream
 Yolk
 Meat
 Egg

49. Forms of Cholesterol
It exist in two states
 Free form E.g. Brain and Nervous
 Bond form E.g. Adrenal Cortex

50. Cholesterol
 Normal level of serum total cholesterol 150 – 250mg%
 Free cholesterol 40-50%
 Cholesterol esters (bond state) 110-200mg%

51. Others Sterols
 7 dehydocholesterol
 Ergosterol
 Stigmasterol and sitosterol
 Coprosterol

52. 7-Dehydocholesterol (Provitamin D or Pre-cholecalciferol)
•Synthesis from cholesterol in the skin and intestinal wall
•Present in skin
Precholecalciferol  cholecalciferol (vit D3)
•Disease: Rickets

53. Ergosterol
 Plant sterol
 Source: Isolated from ergot, fungus of rye
 Same structure as 7 dehydocholesterol except the side chain

54. Stigmasterol and Sitosterol
 Plant sterols, occurs in higher plant
 No nutritional value
 Sitosterol decrease the intestinal absorption of Cholesterol
and low blood cholesterol levels
Coprosterol ( Coprostanol)
 Result of reduction of Cholesterol
(hydrogenation of = bonds) by bacterial action

55. 55
Reference:
Textbook Medical Biochemistry by Chatterjea,
Sixth Edition, Chapter 4
https://www.amazon.com/Textbook-Medical-Biochemistry-M-D-
Chatterjea/dp/9350254840