Riboflavin B2 active coenzyme - FMN,FAD Function - Oxidation reduction reaction, Antioxidant Deficiency- Glossitis, stomatitis, Cheilosis, Seborrhoeic dermatitis, corneal vascularisation etc

2. INTRODUCTION
Riboflavin (vitamin B2) is part of the vitamin B group and
water soluble vitamin. The name of riboflavin comes
from ribose and flavin, the ring moiety which imparts
from the yellow colored to the oxidized molecule.
Riboflavin is absorbed from the small intestines through
the portal vein and is passed on to all tissues by the
general circulation. Excess riboflavin ingested is not
stored in the tissues. A major part is excreted in urine and
a small part is broken down in the tissues.

3. INTRODUCTION
It is the central component of the cofactors FAD and
FMN and as such required for a variety of
flavoprotein enzyme reactions including activation of
other vitamins.

4.  Riboflavin is a yellow pigment
 Riboflavin contains 6,7 –
dimethyl isoalloxazine ring
attached to D-ribitol by a
nitrogen atom
 Ribitol is an open chain form
of sugar ribose with aldehyde
group is reduced to alcohol
STRUCTURE OF RIBOFLAVIN

5.  It emits yellow fluorescence
 It is stable to heat but
sensitive to light
 When exposed to UV rays of
sun light, it is converted to
lumiflavin which exhibits
yellow fluorescence.
STRUCTURE OF RIBOFLAVIN

6. STRUCTURE OF RIBOFLAVIN
 Lactoflavin from milk
 Hepatoflavin from liver
 Ovoflavin from eggs are
structurally identical to
riboflavin.

7. ABSORPTION:

8. TRANSPORT:

9. STORAGE AND EXREATION:

10. COENZYMES OF RIBOFLAVIN

11. BIOCHEMICAL FUNCTIONS

12. BIOCHEMICAL FUNCTIONS

13. REACTIONS REQUIRING FMN

14. REACTIONS REQUIRING FAD

15. REACTIONS REQUIRING FAD

16. REACTIONS REQUIRING FAD

17. PHYSIOLOGICAL FUNCTION
 Riboflavin deficiency affects primarily the octodermal tissues
producing lesions of the skin, eye and nervous system.
 Riboflavin is concerned in the regulatory functions of some
hormones involved in carbohydrate metabolism.
 The retina contains free riboflavin which is converted by light
to a compound involved in stimulation of the optic nerve.

18. PHYSIOLOGICAL FUNCTION
 Riboflavin play an important role in many enzyme systems
involved in the metabolism of carbohydrates,fats and
proteins.
 Flavin mononucleotide(FMN) and Flavin adenine
dinucleotide(FAD) are part of the enzymes or acts as
coenzymes.

19. SOURCES AND RDA

20. EFFECTS OF DEFICIENCY
 The effects of riboflavin deficiency in human beings may be
grouped under the following heads
 Oral and facial lesions:
 Development of angular stomatitis, Glossitis, cheilosis.

21. EFFECTS OF DEFICIENCY
 Ocular lesions:
 The eyes can become itchy, watery, bloodshot and
sensitive to light.