Vitamin Pyridoxine 
And Biotin

INTRODUCTION OF VITAMIN

  • Organic molecules, essential for the normal growth and development, required in tiny amounts
  • Cannot be synthesized by mammalian cells, must be supplied in the diet

THE CLASSIFICATION OF VITAMINS

  • Water-soluble

Thiamine VB1

Riboflavin VB2

Niacin 

Pantothenic acid

Pyridoxine VB6

Biotin VB7

Folic Acid VB11 ? VB9 

CobalaminVB12

Vitamin C VC 

  • Fat-solubleVA, VD, VE and VK 

WATER SOLUBLE VITAMINS: CHARACTERISTICS

  • Essential 
  • Organic Structure
  • Non-energy Producing
  • Micronutrients
  • Stability 
  • Bioavailability
  • Toxicity

THE B VITAMINS

Chief Functions – Important as Coenzymes

i) Thiamin

ii) Riboflavin

iii) Niacin

iv) Pantothenic Acid & 

v) Biotin 

         Involved in Energy Metabolism

Vitamin B-6 involved in Protein 

         Metabolism

– Folate & Vitamin B-12 involved

         in Cell Replication

– Therapeutic doses of Niacin 

         lower cholesterol 

WATER SOLUBLE VITAMINS VS.
FAT SOLUBLE VITAMINS

WATER SOLUBLE VITAMINS VS.
FAT SOLUBLE VITAMINS

Coenzymes

Coenzymes OF VITAMINS

Vitamins are derived from a variety of foods.  

PYRIDOXINE (VITAMIN B6)

  • Vitamin B6 is used to collectively represent

   the three compounds namely:

i. Pyridoxine

ii. Pyridoxal and 

iii. Pyridoxamine

  • Active form of Pyridoxine:

Pyridoxal phosphate (PLP)

DIETARY SOURCES

Rich sources are dried yeast, rice polishing, wheat germs, cereals, legumes, oil seeds, egg, milk, meat, fish and green leafy vegetables.

RDA

  • Requirement of vitamin Bis related to dietary protein intake, as it is involved as coenzyme in many metabolic reactions of amino acid metabolism
  • Adults : 2 mg/day
  • Infants : 0.3 – 0.4 mg/day
  • Vitamin B6 compounds are pyridine derivatives
  • They differ from each other in the structure of a functional group attached to 4th carbon in the pyridine ring

i. Pyridoxine: Primary Alcohol

ii. Pyridoxal: Aldehyde form while

iii. Pyridoxamine: Amine

PYRIDOXINE
4,5-Bis(hydroxymethyl)-2-methylpyridin-3-ol

PYRIDOXINE
4,5-Bis(hydroxymethyl)-2-methylpyridin-3-ol

CO – ENZYME FORM

Pyridoxal phosphate

Pyridoxal phosphate

BIOCHEMICAL FUNCTIONS

  • Transamination
  • Decarboxylation
  • Sulphur containing amino acid
  • Heme Synthesis
  • Production of Niacin

DEFICIENCY MANIFESTATION

  • Neurological manifestation
  • Dermatological manifestation
  • Hematological manifestation

BIOTIN

SYNONYMS:

  • Bios
  • Vitamin H
  • Vitamin 7
  • Co-enzyme R
  • Anti egg white injury factor

Biotin is a sulphur containing B-complex vitamin.

  • In old literature Biotin was known as anti egg white injury factor.
  • Biotin was isolated in 1942 by Vincent du Vigneaud, who was awarded Nobel prize in 1955.

DIETARY SOURCES

  • Normal bacterial flora of the gut will   provide adequate quantity of Biotin
  • Moreover, it is distributed ubiquitously in plant and animal tissues
  • Liver, yeast, peanut, soybean, milk and 

egg yolk are rich sources.

RDA

About 200 – 300 mg will meet the daily requirements.

CHEMISTRY

  • Biotin is a hetrocyclic monocarboxylic acid
  • Sulphur containing water soluble B vitamin
  • Structure of the compound was worked out by du Vigneaud
  • It consist of two fused rings, 

i. Imidazole and 

ii. Thiophene derivative

STRUCTURE BIOTIN

STRUCTURE OF BIOTIN

CO-ENZYME ACTIVITY OF BIOTIN

  • Biotin present in liver as Biocytin (active form of Biotin)
  • Biotin act as a co-enzyme for: 

Carboxylation Reactions

  • In the First Step:

A molecule of CO2 is captured by Biotin

  • The resulting carboxybiotin contains carboxyl group covalently attached to the nitrogen of Biotin molecule.
  • The energy required for this reaction is provided by ATP
  • In the second step: 

Activated carboxyl group is transferred to the substrate and A free biotynyl enzyme is regenerated.  

BIOCHEMICAL FUNCTIONS
Biotin Requiring CO2 Fixation Reactions

  1. Acetyl CoA carboxylase:
  • This enzyme adds CO2 to acetyl coA to  form malonyl CoA.
  • This is the rate limiting reaction in biosynthesis of fatty acids

2. Propionyl CoA Carboxylase:

  • It is another Biotin requiring Enzyme

3. Pyruvate Carboxylase:

  • Fixes CO2 to Pyruvate to form Oxaloacetate

4. Leucine:

  • Required for conversion of β methyl crotonyl CoA to β methyl gluconyl CoA

BIOTIN ANTAGONIST

  • Avidin, a protein present in egg white has great affinity to biotin
  • Hence intake of raw (unboiled) egg may cause biotin deficiency
  • Biotin deficiency was experimentally produced by giving raw egg white
  • Therefore biotin was originally named as anti-egg-white-injury-factor

BIOTIN DEFICIENCY

Biotin deficiency may be produced by:

  • Large quantity of avidin
  • Prolonged use of antibacterial drugs
  • Very rarely, holocarboxylase synthetase enzyme is deficient or absent
  • Leiner’s disease occurs in breast fed young infants with persistent diarrhea

DEFICIENCY SYMPTOMS

  • Dermatitis
  • Atrophic Glossitis
  • Hyperesthesia
  • Muscle pain
  • Anorexia
  • Hallucinations
BIOTIN DEFICIENCY
BIOTIN DEFICIENCY
LEINER’S DISEASE IN INFANTS
LEINER’S DISEASE IN INFANTs

Other Biochemistry Notes :-

Pyrimidine metabolism

Purine Metabolism

Cardiac Biomarkers

. Blood Metabolism (Heme synthesis and breakdown)

Haemoglobinopathies

All books/videos/software featured here are free and NOT HOSTED ON OUR WEBSITE. If you feel that your copyrights have been violated, then please contact us immediately.

Contact us: medicalfarre@gmail.com

2 thoughts on “Vitamin Pyridoxine 
And Biotin”

  1. SQL is the language utilized to develop, upgrade, and modify a data source– pronounced both as ‘Se-quell’ as well as’S-Q-L’. Before beginning with SQL, allow us have a short understanding of DBMS. In straightforward terms, it is software program that is utilized to produce and also take care of databases. We are mosting likely to stick with RDBMS in this write-up. There are also non-relational DBMS like MongoDB made use of for big data evaluation. There are various accounts like information expert, database administrator, and data designer that require the understanding of SQL. Besides guiding you in your interviews, this short article will additionally offer a fundamental understanding of SQL.
    https://interviewtip.net
    I can also recommend “TOP 30 SQL Interview Coding Tasks” by Matthew Urban, actually great book when it pertains to the most common SQL coding interview inquiries. This error usually shows up because of syntax mistakes on-call a column name in Oracle database, observe the ORA identifier in the mistake code. See to it you enter the correct column name. Likewise, take special note on the aliases as they are the one being referenced in the mistake as the void identifier. Hibernate is Item Relational Mapping tool in Java.

Leave a Comment

Your email address will not be published.