this presentation is about Vitamin B6 which include structure , biochemical function , biochemical reaction, effect of deficiency of vitamin B6, Toxicity and function of Vitamin B6.

1. PYRIDOXAL
(VITAMIN B6 )
Seminar presented by
SHAIKH QAMRUNNISA ABDUL
WAHID
Roll no: 18
MSC-I MICROBIOLOGY
(BIOCHEMISTRY)

2. CONTENT:
1. Vitamins
a. History
b. Types of vitamins
2. Pyridoxal
a. Source
3. Pyridoxal phosphate
4. Biochemical functions
5. Biochemical mechanism
A. Transamination reaction
a. Defination
b. General reaction
c. Mechanism
6. Deficiency of vitamin B6
7. Toxicity of vitamin B6
8. Functions of vitamin B6
9. Recommendation

3. VITAMINS:
Vitamins are essential organic substance needed in minute
amounts by the body to perform specific metabolic functions.
HISTORY:
1912- E.V McCollum discovered first fat soluble vitamin,
vitamin A.
1912- Dr.Casmir Frunk coined termed ‘vitamins’ as a vital
factors in diet. found these unidentified substances in food could
prevent diseases of scurvy, beriberi and pellagra (from
deficiency of niacin, vitaminB3)
1940’s-water soluble B and C vitamins were identified.

4. TYPES OF VITAMINS:
• Fat soluble vitamins are vitamins that stored in the fat tissues
and in liver.
• Vitamins A,D,E and K are all fat soluble vitamins.
• Water soluble vitamins does not stored as much in the body.
instead they travel through the blood stream . Whatever your
body does not use comes out through urine.
• Vitamin C and the big group of Vitamins B-
B1(thiamine), B2(riboflavin), niacin, B6 (pyridoxine),
biotin, and pantothenic acid are water soluble vitamins.
Water soluble vitamins:
Fat soluble vitamins:

5. PYRIDOXAL:
Vitamin B6 is water soluble vitamin present in three major
chemical form:
The alcohol form is called as PYRIDOXAL/PYRIDOXINE.
The aldehyde form is called as PYRIDOXAL.
The amine form is called as PYRIDOXAMINE.
3-Hydroxy-2-methyl pyridine

6. SOURCES:

7. PYRIDOXAL PHOSPHATE:
 Pyridoxal phosphate (PLP, pyridoxal 5'-phosphate, P5P), the active
form of vitamin B6, is a coenzyme in a variety of enzymatic reactions.
The Enzyme commission has catalogued more than 140 PLP-
dependent activities.
 The versatility of PLP arises from its ability to covalently bind the
substrate, and then to act as an electrophilic catalyst, thereby
stabilizing different types of carbanionic reaction intermediates.

10. BIOCHEMICAL FUNCTIONS:
1.As co-transaminase : It acts as a coenzyme in
transamination reactions.
2.As co-decarboxylase : It also function as a coenzyme in
non-oxidative decarboxylation of some aminoacids or their
derivatives.
example:
Tyrosine Tyramin+CO2
Histidine Histamine+CO2
3.As Alanine-synthase : in synthesis of aminolevulinic acid
which is an intermediate in heme synthesis.
4.As a coenzyme in the conversion of tryptophan to
niacin.
Tryptophan Niacin

11. 11
5.In transulphuration reaction , where transfer of –SH
group takes place , VitB6 is needed.
6.In synthesis of sphingolipid.
7.Intramitochondrial fatty acid synthesis.
8.Intestinal absorption of aminoacids.
9. Transport of K+ : VitB6 is reported to promote transport
of K+ across the membrane.
10. Synthesis of CoA-SH from pantothenic acid needed
VitB6. in deficiency CoA level of the liver is decreased.
11.VitB6 acts as a coenzyme for glycine synthase.

12. BIOCHEMICAL
MECHANISM
OF VITAMIN
(PYRIDOXAL)
B6

13. TRANSAMINATION REACTION:
DEFINATION: The transfer of α-NH2 group from an
amino acid to an acceptor α-ketoacid (generally α-
ketoglutarate) is called as transamination.
GENERAL REACTION:

14. FATE OF THE α-NH2 GROUP TRANSFER:
It has 2 metabolic fates:-

15. MECHANISM:

17. DEFICIENCY OF VITAMIN B6:
Weakness
Sleepleness
Personality changes
Dermatitis
Anemia
Nerve damage
Peripheral neuropathy
Nausea , loss of appetite
Depression
Mental confusion

18. ECG DURING B6DEFICIENCY:

19. TOXICITY:
 Large dose of Vit B6 cause severe nerve damage.
 More than 200mg/day cause peripheral neuropathy.
 Doses higher than 500mg/day may be toxic, leadingto
serious central nervous system problems , pain in the arms
and legs, clumsiness, loss of balance, and difficulty in
walking.
 High doses of Vit B6 can lead to increased susceptibillity to
cadmium toxicity, cause peripheral neuropathy.

20. FUNCTIONS:
Assists in the balacing of sodium and potassium
levels.
Promotes RBC production.
Production of serotonin, dopamine, noradrenaline
and adernaline.

21. RECOMMEDATION:

22. SUMMARY:
 Vitamins are essential organic substance needed in minute amounts by the body
to perform specific metabolic functions.
 Vitamins are of two types:
I. Fat soluble vitamin : A,D,E and K.
II. Water solublevitamins : C and B.
 Three major classical form of Vitamin B6:
I. PYRIDOXAMINE.
II. PYRIDOXAL.
III. PYRIDOXAL/PYRIDOXINE.
 Pyridoxal phosphate : pyridoxal phosphate is the active form of vitamin B6 is a
coenzyme in a variety of enzymatic reactions.
 Biochemical mechanism:
Transamination : The transfer of α-NH2 group from an amino acid to an acceptor
α-ketoacid is called as transamination.
 Function of vitamin B6:
I. Balance sodium and potassium level.
II. Promotes RBC production.

23. REFRENCES:
i. www.google.com
ii. The foundation of biochemistry-lehninger.