Derived lipids

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) Straight chain FA Branched chain FA Substituted FA Cyclic FA Eicosanoids

6. Straight Chain FA Saturated FA Unsaturated FA

7. Saturated FA Contains no double bonds. Formula: C n H 2n+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 CH 3 COOH Propionic acid C 2 H 5 COOH Butyric acid C 3 H 7 COOH Caproic acid C 5 H 11 COOH Examples of higher fatty acids Palmatic acid C 15 H 31 COOH Stearic acid C 17 H 35 COOH

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 C ontains 1 double bond in a chain. Formula : C n H 2n-1 COOH Present in all fats Oleic Acid C 17 H 33 COOH

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: C n H 2n-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: C n H 2n-5 COOH Linolenic acid

15. Arachidonic acid series Source : Animal fats such as liver fat contains 4 double bonds Formula: C n H 2n-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 ( C 18 H 32 O 2 ) obtained from Chaulmoogra seeds Used for leprosy treatment Chaulmoogric acid ( C 18 H 32 O 2 )

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 Oct anoic acid Unsaturated FA ends “ enoic ” Example Octadec enoic (oleic)

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

26. 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

27. 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

28. Omega −3 fatty Three types of omega−3 fatty acids involved in human physiology are  α- L inolenic acid (ALA ) ( 18C and 3 double bonds ) E icosapentaenoic acid (EPA)   (20C and 5 double bonds) Docosahexaenoic acid (DHA ) ( 22C and 6 double bonds )

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

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

31. Flow chart of lipid classification   Geometric

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

33. Nomenclature Positional Isomerism Variation in the location of double bonds along the unsaturated fatty acid

34. 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

35. 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

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

37. 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

38. 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

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

40. (a)  Phytol (C 20 H 40 O): 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.

41. ( b)  Lycophyll C 40 H 56 O 2 A polyunsaturated dihydroxy alcohol Occurs in tomatoes as a purple pigment

42. (c) Carotene ( C 40 H 56 ) Easily split in the body at the central point of the chain to give two molecules of alcohol, vitamin A.

43. (d) Sphingosine or Sphingol (  ‎C 18 H 37 NO 2 ) Unsaturated Amino alcohol Present as a constituent of Phospholipid (Sphingomyelin) Glycolipids

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

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

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

47. 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

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

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

50. Others Sterols 7 dehydocholesterol Ergosterol Stigmasterol and sitosterol Coprosterol

51. 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

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

53. 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

54. 55 Reference: Textbook Medical Biochemistry by Chatterjea , Sixth Edition, Chapter 4 https://www.amazon.com/Textbook-Medical-Biochemistry-M-D-Chatterjea/dp/9350254840