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1. BIOCHEMISTRY
[B. Pharm – I Yr.]
Topic: HMP Shunt
Umesh Kumar
Assistant Professor
Dept. of Pharm. Chemistry
Hygia Institute of Pharmaceutical Education and Research

2. CONTENTS
• HMP Shunt Pathway
• Introduction
• Location of HMP Pathway
• Reactions of HMP Pathway
• Complete pathway
• Significance of HMP shunt

3. Introduction
• Hexose monophosphate pathway or HMP shunt is also called pentose phosphate
pathway or phosphogluconate pathway.
• This is an alternative pathway to glycolysis and TCA cycle for the oxidation of
glucose.
• However, HMP shunt is more anabolic in nature, since it is concerned with the
biosynthesis of NADPH and pentoses.
• The pathway starts with glucose 6-phosphate.
• As such, no ATP is directly utilized or produced in HMP pathway.
• It is a unique multifunctional pathway, since there are several interconvertible
substances produced which may proceed in different directions in the metabolic
reactions.

4. Location of HMP Shunt Pathway
• The enzymes of HMP shunt are located in the cytosol.
• The tissues such as liver, adipose tissue, adrenal gland, erythrocytes, testes and
lactating mammary gland, are highly active in HMP shunt.
• Most of these tissues are involved in the biosynthesis of fatty acids and steroids
which are dependent on the supply of NADPH.

5. Reactions of HMP Pathway
The sequence of reactions of HMP shunt is divided into two phases-oxidative and
non-oxidative.
1. Oxidative Phase:
• Glucose 6-phosphate dehydrogenase (C6PD) is an NADP-dependent enzyme that converts
glucose 6-phosphate to 6-phosphogluconolactone.
• The latter is then hydrolysed by the gluconolactone hydrolase to 6-phosphogluconate.
• The next reaction involving the synthesis of NADPH is catalysed by 6-phosphogluconate
dehydrogenase to produce 3 keto 6-phosphogluconate which then undergoes decarboxylation to
give ribulose 5-phosphate.
2. Non-oxidative Phase:
• The non-oxidative reactions are concerned with the interconversion of three, four, five and
seven carbon monosaccharides.
• Ribulose 5-phosphate is acted upon by an epimerase to produce xylulose 5-phosphate while
ribose 5-phosphate ketoisomerase converts ribulose S-phosphate to ribose 5-phosphate.

6. Overview of the Pathway

7. Pathway

9. Significances of
HMP Shunt
Pentoses
(Riboses)
Nucleic acids
(RNA and DNA)
Nucleotides
(ATP, FAD, NAD+ and
CoA
NADPH
-Fatty acids,
-Steroids,
-Amino acids,
-Required for the Phagocytosis,
-Helps in detoxification of drugs
and foreign particles,
-Maintains the concentration of
Glutathione
Significance of HMP Pathway

10. Conti…..
Importance of Pentoses
• In the HMP shunt, hexoses are converted into pentoses, the most important being ribose-5- phosphate.
• This pentose or its derivatives are useful for the synthesis of nucleic acids (RNA and DNA) and many
nucleotides such as ATP, NAD+ , FAD and CoA.
Importance of NADPH
• NADPH involved in the biosynthesis of fatty acids and steroids.
• This is also used in the synthesis of certain amino acids by using enzyme glutamate dehydrogenase.
• NADPH supply requires in the phagocytosis, phagocytosis is the engulfment of foreign particles
including microorganisms, carried out by white blood cells.
• NADPH also helps in the detoxification of drugs and foreign compounds by hydroxylation reactions.
• NADPH produced in erythrocytes (RBC) has special functions to perform, it maintains the
concentration of reduced glutathione which is essentially required to preserve integrity of RBC
membrane.
• High concentration of NADPH in lens of eyes is necessary to preserve the transparency of the lenses.

11. THANK YOU
HYGIA GROUP OF INSTITUTIONS
GHAILA ROAD, GAAZIPUR BALRAM,
FAIZULLAHGANJ, LUCKNOW