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Pyridoxine

Presented by:

MUHAMMAD AIMAN BIN ARIFIN

MUHAMMAD LUQMAN BIN YUNUS

AHMAD IZZUDDIN BIN MAZLAN

AMIRUL HUSSAINI BIN BUJANG

AIMI SYAIRAH BINTI ISMAIL

BALQIS BINTI MUHAMAD KASIM

NUR SYAHIRAH BINTI TUMIRAN

5th march 2013

PYRIDOXINE

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Learning Outcomes

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Natural Sources of Vitamin B6

Beans, legumes, nuts,

eggs, meats, fish,

breads, cereals

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Structure

Derivatives of Purine Ring

Purine Ring

Pyridoxine

2-Methly, 3-Hydroxy, 4,5-diHydroxyMethyl Pyridine

Pyridoxine

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Structure

Pyridoxal

Purine Ring

Pyridoxal

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Structure

Pyridoxamine

Purine Ring

Pyridoxamine

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PM

PL

PN

PMP

PLP

PNP

PMPL

PLP PMP

alkaline phosphatase alkaline phosphatase

PNP oxidase

PNP oxidase

PNP oxidase

PNP oxidase

PL kinase

PLP phosphatase

PL kinase

PLP phosphatase

PL kinase

PLP phosphatase

PAaldehyde oxidase

ECF

ICF

Metabolism of Vitamin B6

PL pyridoxal

PLP pyridoxal phosphate

PM pyridoxamine

PMP pyridoxamine phosphate

PN pyridoxine

PNP pyridoxine phosphate

PA

pyridoxic acid

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Therefore, there are six forms of vitamin B6:

1)pyridoxal (PL),2)pyridoxine (PN),

3)pyridoxamine (PM),

4)pyridoxal 5'-phosphate (PLP),

5)pyridoxine 5'-phosphate (PNP),6)pridoxamine 5'-phospate (PMP).

4-pyridoxic acid (PA) is the catabolite which is excreted

in the urine.

PLP is the active coenzyme form, and has the most

importance in human metabolism.

http://www.vitamins-supplements.org/coenzyme-Q10.phphttp://www.vitamins-supplements.org/coenzyme-Q10.php

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1. Transamination reaction, are catalyzed by amino transferases

(transaminases) which employ PLP as the coenzyme.

-keto Glutarate(New -keto acid)

Alanine(New -amino acid)

Pyruvate(Recipient -keto acid)

Glutamate(Donor-amino acid)

SGPT

B6-P / PLP

+ +

SGPT - Serum Glutamate Pyruvate Transaminase

Biochemical role of vitamin B6(pyridoxine)

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2. Decarboxylation of amino acids require PLP catalyzed by decarboxylases.

i. Histidine

Histamineii. Cysteine Taurine

iii. 5-hydroxy tryptophan serotonin

iv. Glutamate GABA (gamma amino butyric acid)

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3. PLP is required for the formation of haemoglobin and the

growth of red blood cells

It acts as coenzyme for the enzyme ALA synthase, in the first stepof heme biosynthesis.

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4. PLP is required for the synthesis of niacin (vitamin B3) from trytophan.

Tryptophan

NIACIN

Kynurenine

3-OH-Kynurenine

3-OH-Anthranilic Acid

Kynureninase

B6-P / PLP

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5. In glycogenolysis, both muscle and liver phosphorylases

(glycogen to glucose-1-phosphate) requires PLP as coenzyme.

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Other functions of Vitamin B6

Neurotransmitter synthesis

Gene expression

Formation of ceramide and sphingolipid

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Deficiency

Anemia (involved in heme synthesis)

Glossitis-inflammation of the tongue

Scaly dermatitis

Cheilosis

Seizures

Scaly dermatitisCheilosis

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Toxicity

Nerve irritation

Headaches

Severe fatigue

Insomnia

Nerve damage

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References

Biochemistry Instant Notes for Medical Students; SeetharamaiahChittiprol

Textbook of Biochemistry for Medical Students; DM Vasudevan,

Sreekumari S, Kannan Vaidyanathan

http://pathman.smpdb.ca/pathways/SMP00017/pathway?level=2

http://www.vitamins-supplements.org/vitamin-B6-pyridoxine.php

http://ods.od.nih.gov/factsheets/VitaminB6-QuickFacts/

http://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/

http://pathman.smpdb.ca/pathways/SMP00017/pathway?level=2http://pathman.smpdb.ca/pathways/SMP00017/pathway?level=2http://www.vitamins-supplements.org/vitamin-B6-pyridoxine.phphttp://www.vitamins-supplements.org/vitamin-B6-pyridoxine.phphttp://ods.od.nih.gov/factsheets/VitaminB6-QuickFacts/http://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/http://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/http://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/http://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/http://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/http://ods.od.nih.gov/factsheets/VitaminB6-QuickFacts/http://ods.od.nih.gov/factsheets/VitaminB6-QuickFacts/http://ods.od.nih.gov/factsheets/VitaminB6-QuickFacts/http://ods.od.nih.gov/factsheets/VitaminB6-QuickFacts/http://www.vitamins-supplements.org/vitamin-B6-pyridoxine.phphttp://www.vitamins-supplements.org/vitamin-B6-pyridoxine.phphttp://www.vitamins-supplements.org/vitamin-B6-pyridoxine.phphttp://www.vitamins-supplements.org/vitamin-B6-pyridoxine.phphttp://www.vitamins-supplements.org/vitamin-B6-pyridoxine.phphttp://www.vitamins-supplements.org/vitamin-B6-pyridoxine.phphttp://www.vitamins-supplements.org/vitamin-B6-pyridoxine.phphttp://www.vitamins-supplements.org/vitamin-B6-pyridoxine.phphttp://pathman.smpdb.ca/pathways/SMP00017/pathway?level=2http://pathman.smpdb.ca/pathways/SMP00017/pathway?level=2http://pathman.smpdb.ca/pathways/SMP00017/pathway?level=2

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Thank You

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Role in Amino Acid Metabolism

Pyridoxal-P

Pyruvic Acid

(Recipient -keto acid)Glutamate

(Donor-amino acid)

Mechanism of TRANSAMINATION Reaction

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Pyridoxal-P

Glutamate

(Donor-amino acid)

Role in Amino Acid Metabolism

Pyridoxal-P

Pyruvic Acid

(Recipient -keto acid)Glutamate

(Donor-amino acid)

-keto Glutarate

(New -keto acid) Pyridoxamine-P

Mechanism of ReactionMechanism of TRANSAMINATION Reaction

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Pyruvic Acid

(Recipient -keto acid)

Role in Amino Acid Metabolism

Pyridoxal-P

Pyruvic Acid

(Recipient -keto acid)Glutamate

(Donor-amino acid)

-keto Glutarate

(New -keto acid) Pyridoxamine-PAlanine

(New -amino acid)

Pyridoxal-P

Mechanism of TRANSAMINATION Reaction

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Role in Amino Acid Metabolism

General Amino Acid Reactions

Decarboxylation Reactions

Removal of CO2 to produce AMINES

Decarboxylase

B6-P

CO2

Histidine

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Role in Amino Acid Metabolism

General Amino Acid Reactions

Decarboxylation Reactions

Removal of CO2 to produce AMINES

Decarboxylase

B6-P

CO2

HistamineHistidine

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Role in Amino Acid Metabolism

General Amino Acid Reactions

Decarboxylation Reactions

Removal of CO2 to produce AMINES

Decarboxylase

B6-P

CO2

HistamineHistidine