water soluble

1. SIMS 305- Clinical Biochemistry
Dr. Ali Raza
Senior Lecturer
Centre for Human Genetics and Molecular Medicine (CHGMM),
Sindh Institute of Medical Sciences (SIMS), SIUT.

2. Water soluble vitamins

3. Water-Soluble vitamins
hydrophilic compounds
• Not readily stored
• Excreted from the body
• Daily intake is important
• Function: Enzyme cofactors

4. 2-Water soluble vitamins:
Vit. B group
B1 (Thiamin)
B2 (Riboflavin)
B3 (Niacin)
B5 (Pantothenic acid)
B6 (Pyridoxine)
B7 (Biotin)
B9 (Folic acid)
B12 (Cyanocobalamin)
Vit. C : (Ascorbic acid)

5. Vitamin B1 (Thiamine)

6. Vitamin B1 (Thiamine)

7. Vitamin B1 (Thiamine)
• Thiamine pyrophosphate, TPP (Thiamine diphosphate) =
Active form
• TPP is synthesized by an enzymatic transfer of pyrophosphate
group from ATP to Thiamine

8. Vitamin B1 (Thiamine)
• Coenzyme for multi-enzyme
complex
• This complex catalyzes
oxidative decarboxylation of
a-keto acids
– pyruvate dehydrogenase in
Carbohydrate metabolism,
– a-ketoglutarate
dehydrogenase → Citric
acid cycle,
– keto-acid dehydrogenase
– TPP is coenzyme for
transketolase – Pentose
phosphate Pathway.

9. Vitamin B1 - deficiency
1. Mild deficiency – Gastrointestinal complaints, weakness
2. Moderate deficiency - Peripheral neuropathy, Ataxia
Mental abnormalities,
3.Full-blown deficiency
Beri-beri – Characterized with severe muscle weakness,
Muscle wasting and delirium (acutely disturbed state of mind )
Paresis(muscular weakness caused by nerve damage ) of the eye muscles,
Degeneration of the cardiovascular system
Memory loss

10. Vitamin B2 (Riboflavin)

11. Vitamin B2 (Riboflavin)

12. Vitamin B2 (Riboflavin)
• Serves as coenzymes of a number of enzymes are the
phosphorylated derivatives.
• Flavin mononucleotide (FMN)
• Flavin adenine dinucleotide (FAD)

13. • FMN → ATP-dependent phosphorylation of riboflavin
• FAD → further reaction with ATP in which its AMP is
transferred to FMN.
Vitamin B2 (Riboflavin)

14. FMN → ATP-dependent phosphorylation of riboflavin
FAD → further reaction with ATP in which its AMP moiety is
transferred to FMN.
Vitamin B2 (Riboflavin)

15. Vitamin B2 (Riboflavin)
• Has a central role in energy-yielding metabolism.
• Flavin coenzymes are electron carries in oxidoreduction
reaction.

16. FMN and FAD function
• FMN and FAD act as prosthetic groups of many oxidoreduction
enzymes, flavo-protein:
• Succinate dehydrogenase – Citric Acid cycle

17. FMN and FAD function
• Mitochondrial glycerol-3-phosphate dehydrogenase – transport of
reducing unit (H+)
• Coenzymes in hydrogen transfer – formation of reducing forms -
FADH2

18. Sources of vitamin B2
• liver,
• beef,
• milk,
• Dairy products,
• Fish
• cocoa,
• nuts,
http://health.allrefer.com/health/nutrition.html

19. • Absorption : Proximal intestine
• Stored mainly in the form of FAD (70- 90%) or FMN.
• Liver
• Kidney
• Heart
Absorption and storage of Vitamin B2 (Riboflavin)

20. Vitamin B2 – Symptoms of Deficiency
• Cracked and Red lips.
• Inflammation of the lining of mouth and tongue.
• Dry and scaling skin-
Keratitis (nflammation of the cornea of the eye),
Dermatitis (inflammation of the skin)
Iron-deficiency anemia

21. Vitamin B3 - Niacin

22. Vitamin B3 - Niacin
• Active form – Nicotinic acid
Nicotinamide

23. Vitamin B3 - Niacin
• Nicotinamide Adenine Dinucleotide (NAD)
• Nicotinamide adenine dinucleotide phosphate (NADP)
• key components of the metabolic pathways of
– Carbohydrates
– Lipids
– Amino acids
Nicotinamide
Adenine

24. Sources of vitamin B3
• foods of animal origin
• yeast
• sunflower seeds, beans, peas
• green leafy vegetable
• broccoli, carrots

25. • Absorption:
– At low concentration by Active transport.
– At high concentration by Passive diffusion.
• Transportation:
– Both nicotinic acid and nicotinamide bind to
plasma proteins for transportation.
Vitamin B3 - Niacin

26. – The liver can synthesize Niacin from the essential
amino acid Tryptophan
– Synthesis is extremely slow
– 60 mg of Tryptophan= 1mg of niacin
– Also required Requires vitamin B6 for reaction.
– Bacteria in the gut may also perform the conversion
but are inefficient.
Biosynthesis: Vitamin B3 - Niacin

27. Vitamin B3 - Niacin
• High dose of niacin dilates blood vessels .
• Nicotinic acid
Prevents the release of fatty acids from adipose tissue
Decreases lipoproteins VLDL, IDL a LDL.

28. • Milder deficiencies: Dermatitis around the mouth and rashes,
fatigue, irritability, poor appetite, indigestion, diarrhea, headache.
• Severe deficiency: Pellagra (diarrhoea, dermatitis and
dementia)
• The main results of pellagra "the four D's":
diarrhea, dermatitis, dementia, and death.
• Pellagra is very rare now, except
– alcoholics,
– strict vegetarians,
– very poor nutrition
Vitamin B3 -Deficiency

29. Vitamin B5 – Panthotenic acid

30. Vitamin B5 – Panthotenic acid
• Consists of pantoic acid and b-alanine.

31. Vitamin B5 – Panthotenic acid
• Part of Acetyl-CoA consists of panthtenic acid

32. Vitamin B5 – panthotenic acid
• Co-enzyme A assists the following reactions:
– Formation of sterols (cholesterol and 7-dehydrocholesterol).
– Formation of fatty acids.
– Formation of keto acids such as pyruvic acid.

33. Vitamin B5 - Deficiency
• Rare to occur
• Disorders of the synthesis of acetylcholine
(a compound which occurs throughout the nervous
system, in which it functions as a neurotransmitter)
• leads to Paresthesias
(an abnormal sensation, typically tingling or pricking
(‘pins and needles’), caused chiefly by pressure on or
damage to peripheral nerves).

34. Sources of vitamin B5
• meat
• yeast,
• broccoli,
• Avocado

35. Vitamin B6
(pyridoxine and pyridoxamine)

36. Vitamin B6
.
Biological ‘active’ forms
• Pyridoxal-PO4
• Pyridoxamine-PO4
• The active forms are the phosphorylated derivatives,
phosphorylation involves the hydroxymethyl group –
CH2OH at position 5 in the pyridine ring.

37. Vitamin B6
• Essential for red blood cell metabolism and hemoglobin
formation.
• Nervous and immune systems to function efficiently.
• Conversion of tryptophan to niacin (vitamin B3).
• Maintain blood glucose.
When caloric intake is low, vitamin B6 helps to convert stored
carbohydrate or other nutrients to glucose to maintain normal
blood sugar levels.

38. Vitamin B6 deficiency
Skin:
-Dermatitis (skin inflammation),
-Stomatitis (inflammation of the mucous lining of any of
the structures in the mouth),
-Glossitis (inflammation or infection of the tongue )
• Neurological abnormalities:
Depression, confusion, and convulsions.
• Anemia.

39. Vitamin B6 – sources
• cereals,
• beans,
• meat,
• liver,
• fish,
• yeast,
• nuts
• banana
• potatoes.
• It is also produced by
bacterial flora in the colon.

40. Vitamin B7 - Biotin

41. Vitamin B7 - biotin
• Heterocyclic monocarboxylic acid
• Sulphur-containing water-soluble B-vitamin.
• Consists of two fused rings, one imidazole and the
thiophene derivative.

42. Biotin – source
• Human beings cannot synthesize the vitamin
• Bacterial flora in intestine can synthesize the vitamin and is
a good source.
• liver
• meat
• kidney
• yeast
• egg yolk
• mushrooms
• milk and diary products.

43. Vitamin B9 – Folic acid

44. Vitamin B9 – Folic acid
• Pteridine + Paraaminobenzoic acid (PABA) + Glutamic
acid

45. Vitamin B9 – folic acid
• Active “coenzyme” form of the vitamin is the reduced
tetrahydroderivative, Tetrahydrofolate F.H4,
• Obtained by addition of four hydrogens to the pteridine at
5, 6, 7 and 8 position.

46. Vitamin B9 - Folic acid deficiency
• Deficiency results in elevated levels of homocystein
(is a non-protein α-amino acid. It is a homologue of
the amino acid cysteine, differing by an additional
methylene bridge (-CH2-).
• A high level of homocysteine in the blood makes a
person more prone to endothelial cell injury
• Deficiency in pregnant women can lead to birth
defects.

47. Sources of Folic acid ( vit B9)
• sources of animal origin
• milk and milk products
• yeast
• greens

48. Vitamin B12 - Cobalamin

49. Vitamin B12 - Cobalamin
Central portion consists of four reduced and extensively
substituted pyrrole rings, surrounding a single cobalt atom
(Co). This central structure is called as Corrin Ring system.

50. Vitamin B12 - Cobalamin
• Complex of organic compounds atom within the
molecule is Co, similar to the heme.
• In man, there are two metabolically active forms:
– Methylcobalamin
– Adenosylcobalamin.

51. Vitamin B12 - Cobalamin
• Cobalamin catalyses two reactions
– Cytoplasmic methylation of homocystein to
methionine.
– Helps Mitochondrial methylmalonyl-CoA mutase
(methylmalonyl-CoA → succynyl-CoA) needs deoxy
adenosylkobalamin.

52. Vitamin B12 – Cobalamin
• Essential for the maturation of erythrocytes.
• Protects against pernicious anemia (loss of stomach cells
that make intrinsic factor, B12).
• Essential for cell growth and reproduction.
• Essential for the formation of myelin
(a mixture of proteins and phospholipids forming a whitish
insulating sheath around many nerve fibres, which increases
the speed at which impulses are conducted) and
nucleoproteins.

53. Vitamin B12 – Cobalamin
• Vitamin B12 in food is bound to the protein.
• Hydrochloric acid in the stomach releases free
vitamin B12.
• Once released vitamin B12 combines with a
substance (glycoproteins) called intrinsic factor (IF).
• This complex can then be absorbed by the intestinal
tract.

54. Sources of vitamin B12
• fish and shellfish,
• meat (especially liver),
• poultry,
• eggs,
• milk, and
• milk products

55. Vitamin C
• Vitamin C is a water-soluble vitamin.
• Almost all animals and plants synthesize their own vitamin
C, not man.
• Vitamin C was first isolated in 1928 and in 1932
• Vitamin C is a weak acid, called ascorbic acid or its salts
“ascorbates”.
• it was proved to be the agent which prevents scurvy
(swollen bleeding gums and the opening of previously
healed wounds).

56. The role of vitaminC
• Cofactor in the synthesis of norepinephrine
(hormone and neurotransmitter) from dopamine.
• Involved in a variety of metabolic processes ;
oxidation-reduction reactions and cellular
respiration,
• carbohydrate metabolism,
• synthesis of lipids and proteins
• Antioxidant and free radical scavenger → maintain
proper immune system.

57. The role of vitaminC
• T-lymphocyte activity, phagocyte function,
leukocyte mobility, and possibly antibody and
interferon production seem to be increased by
vitamin C.
• Involved in the synthesis of collagen, the major
component of ligaments, tendons, cartilages and
skin.
• Involved in tyrosine metabolism.

58. Deficiency of vitaminC
• Fatigue, personality changes, decline in psychomotor
performance and motivation.
• Vitamin C deficiency over 3-5 months results in symptomatic
scurvy.
• Scurvy leads to the formation of liver spots on the skin,
spongy gums, and bleeding from all mucous membranes.
• In advanced scurvy there are open, suppurating wounds and
loss of teeth. Severe scurvy may progress to neuritis, jaundice,
fever, dyspnea (difficult breathing), and death.

59. Vitamin C as antioxidant

60. Good Luck