Two biologically active forms Flavin mononucleotide (FMN) Flavin adenine dinucleotide (FAD) FAD and FMN are derived from riboFlavin (B2 = 2 ATP) deficiency: Cheilosis (inflammation of lips, scaling and fissures at corners of mouth) Dermatitis Glossitis (tongue smooth and purplish) vit B3 Derived from tryptophan Two biologically active forms Nicotinamide Adenine Dinucleotide (NAD+) Nicotinamide Adenine Dinucleotide Phosphate (NADP+) NAD derived from Niacin (B3 = 3ATP)

1. VITAMINS B2, B3, B5, B6, B7
Maryam Fida (o-1827)
Source: Biochemistry – Lippincott’s Illustrated Reviews
World Wide Web

2. RIBOFLAVIN (VITAMIN B2)
Two biologically active forms
■ Flavin mononucleotide (FMN)
■ Flavin adenine dinucleotide (FAD)
■ FAD and FMN are derived from riboFlavin (B2 = 2 ATP)

3. ■ Formed by the transfer of an adenosine monophosphate moiety from ATP to FMN

4. Cofactor in oxidation and reduction
■ FMN ↔ FMNH2
■ FAD ↔ FADH2

5. Deficiency
■ Cheilosis (inflammation of lips, scaling and fissures at corners of mouth)
■ Dermatitis
■ Glossitis (tongue smooth and purplish)

6. Vitamin B3 (Niacin)
Derived from tryptophan
Two biologically active forms
■ Nicotinamide Adenine Dinucleotide (NAD+)
■ Nicotinamide Adenine Dinucleotide Phosphate (NADP+)
■ NAD derived from Niacin (B3 = 3ATP)

7. Cofactor in oxidation and reduction
■ NAD+ ↔ NADH
■ NADP+ ↔ NADPH

8. Deficiency (Pellagra)
The 3Ds of B3
■ Diarrhoea
■ Dermatitis
■ Dementia

9. Use
Treatment of hyperlipidemia
■ Inhibits lipolysis in adipose tissue—the primary producer of circulating free fatty
acids

10. Vitamin B5 (Pantothenate /
PANTOTHENIC ACID)
■ component of coenzyme A (CoA),
which functions in the transfer of acyl groups
■ Also a component of fatty acid synthase
■ B5 is “pento”thenate

11. Deficiency
■ Not well characterized
■ Dermatitis
■ Enteritis
■ Alopecia

12. Biotin (B7)
■ Coenzyme in carboxylation reactions
(which add a 1-carbon group)
■ Buy a tin of CO2

13. Deficiency
■ Rare
■ large percentage of the biotin requirement in humans is supplied by intestinal
bacteria
■ Avidin in egg whites avidly binds biotin

14. VITAMIN B6
(PYRIDOXINE)

15. PYRIDOXINE (VITAMIN B6)
■ Vitamin B6 is a collective term for pyridoxine (found in plants), pyridoxal and pyridoxamine
(found in animals), all derivatives of pyridine
■ All three compounds can serve as precursors of the biologically active coenzyme, pyridoxal
phosphate (PLP)
■ PLP functions as a coenzyme for a large number of enzymes , particularly those that
catalyze reactions involving amino acids , for example, in the synthesis of cysteine from Hcy

17. Clinical indications for Pyridoxine
■ Isoniazid, a drug commonly used to treat tuberculosis , can induce a vitamin B6 deficiency by
forming an inactive derivative with PLP
■ Dietary supplementation with B6 is, thus, an adjunct to isoniazid treatment.

18. Toxicity of Pyridoxine
■ Pyridoxine is the only water-soluble vitamin with significant toxicity
■ Neurologic symptoms (sensory neuropathy) occur at intakes above 500 mg/day,
an amount nearly 400 times the Recommended Dietary Allowance (RDA)