2. POLYSACCHARIDES – Most of the carbohydrates found
in nature occur in the form of high molecular polymers called
polysaccharides
Polysaccharides are of two types :
a) Homopolysaccharides
b) Heteropolysaccharides
HOMOPOLYSACCHARIDES – polymer of same
monosaccharide units
eg : Starch, Glycogen, Inulin, Cellulose, Pectin, Chitin.
HETEROPOLYSACCHARIDES – polymer of different
monosaccharide units
eg : Mucopolysaccharides
3. DEFINITION:
Heteropolysaccharides are High-molecular
weight carbohydrate polymers more than
one kind of monosaccharide.
Chemically, they are formed mostly of repeated
disaccharides units that contain amino sugar (N-
acetyl glucosamine or N-acetyl galactosamine)
uronic acid (glucuronic acid or its 5 epimer iduronic
acid).
4. Mucopolysaccharides or Glycosaminoglycans(GAGs):
Glycosaminoglycans (GAGs) or mucopolysaccharides are long
unbranched polysaccharides consisting of a repeating
disaccharide unit.
GAGs-High-Molecular-weight carbohydrate polymers.
Glycosaminoglycans forming the proteoglycans are the
most abundant heteropolysaccharides in the body.
They are long unbranched molecules containing a repeating
disaccharides unit. One or both sugars contain Sulfate
Groups(the only exception is Hyaluronic acid).
5. Function of Glycosaminoglycans. (GAGS)
They have the special ability to bind large amounts
of water, there by producing the gel-like matrix
that forms the basis of the body’s ground substance.
Since they are negatively charged, for example, in
bone, glycosaminoglycans attract and tightly bind
cations like ca++, they also take-up Na+ and K+.
GAGs stabilize and support cellular and fibrous
components of tissue while helping maintain the water
and salt balance of the body.
6. Its essential components of the extra cellular
matrix, GAGs play an important role in mediating
cell-cell interactions
Ground substance is a part of connective tissue,
which is a gel like substance containing water, salt,
proteins and polysaccharides.
An example of specialized ground substance is the
synovial fluid, which serves as a lubricant in
joints, and tendon sheaths.
7. Types:
GAGs are either sulfate group free or sulfate
group containing
GAGs are sulfate group free(Hyaluronic
acid)
GAGs are sulfate group containing as
Chondroitin sulfate
Heparin
Keratan sulfate and
Dermatan sulfate.
8. Hyaluronic acid: (also called Hyaluronan
or hyaluronate or HA)
A gel like aminoglycan that is found in the tissue space, the
synovial fluid of joints, and the vitreous humor of the eyes and
acts as a binding, lubricating, and protective agent.
Hyaluronic acid is unique among the GAGs because it does
not contain any sulfate and is not found covalently
attached to proteins.
It forms non-covalently linked complexes with proteoglycans in
the ECM.
Hyaluronic acid polymers are very large (100-10,000 kD)and
can displace a large volume of water.
9. Found in :
Synovial fluid.
Vitreous humor of the eye.
Skin and loose connective tissue.
Cartilage
Epithelial
Neural tissues
10. Structure of Hyaluronic acid:
Repeated disaccharide units, composed of glucuronic
acid and N-acetyl glucosamine.
11. Functions of Hyaluronic acid:
Gel made of Hyaluronic acid has good resistance to
compression, thus it acts as lubricant and shock
absorber in the synovial fluid.
It makes extra cellular matrix loose, because of its
ability to attract water.
It forms an important part of cementing ground
substance.
Secreted by Cercaria (infective stage of bilharziasis)
to help penteration of skin.
12. Hyaluronic acid is utilized extensively in various
areas like Cosmetic, Dietary supplement,
Parenteral nutrition, and Intraocular injection.HA
is processed differently for the use in these area
of function based on specification and purity of
the product.
Hyaluronic acid retains water like a sponge and
has the ability to absorb a thousand times more
than its own weight and play an important role in
Tissue hydration,Lubication and Cellular
function.In short it is an excellent skin moisturizer.
13. Applications:
Due to its high Biocompatibility and its common presence
in the extracellular matrix of the tissues.
Hyaluronan is gaining popularity as a biomaterial
Scaffold in tissue engineering research and producing a Hydrogel.
This added feature allows a researcher to form a desired shape
as well as to deliver therapeutic molecules into a host.
Hyaluronan can be crosslinked by attaching
Thiols
Methacrylates and
Thyramines.
Hyaluronan can also be crosslinked directly with
Formaldehyde
Divinylsulfone
14. CHONDROITIN SULFATE
Definition: Chondroitin sulfate is a sulfated
glycosaminoglycan (GAG) composed of a chain of
alternating sugars (N- acetylgalactosamine
and glucuronic acid). It is usually found attached to
proteins as part of a proteoglycan.
A chondroitin chain can have over 100 individual sugars,
each of which can be sulfated in variable positions and
quantities.
Chondroitin sulfate is a chemical that is normally found in
cartilage around joints in the body. Chondroitin sulfate is
manufactured from animal sources such as cow
cartilage.
16. Found in :
Cartilage
Tendons
Ligaments
Bones
Aorta
Skin
Cornea.
17. Functions of chondroitin sulphates:
It has a role in binding collagen of cartilage and holding its
fibers together. Compressibility of cartilage in weight bearing
is due to chondroitin sulfate.
Chondroitin is in dietary supplements used as an alternative
medicine to treat osteoarthritis and also approved and
regulated as a symptomatic slow-acting drug for this disease
(SYSADOA) in Europe and some other countries.
It is commonly sold together with glucosamine. Chondroitin
and glucosamine are also used in veterinary medicine.
It has a weak anticoagulant property.
18. Heparin
Heparin is Heterogeneous mixture of unbranched
polysaccharides chains.
Alternating monosaccharides units of L-iduronic acid and
D-glucosamine.
The molecular size in the natural extract is 2 to 40kDa.
One third of the polysaccharide chains contains a specific
Anti-thrombin binding Pentasaccharide sequences.
19. It is an anticoagulant present in liver
It is produced mainly by mast cells of liver
Found in :
Lungs
Thymus
Spleen
Walls of large arteries skin and
Small quantities in blood
20. Structure of Heparin
Disaccharide repeated units of
Iduronic acid with sulfate on C2
Glucosamine with sulfate on C3 and C6.
21. Heparin-Clinical Use
Prophylactics of DVT and PE
-Preventation of formation of thrombin
-Low dose reginmens
-High risk groups (acute myocardial infraction, Surgery)
Treatment of DVT and PE
-Preventation of further thrombin generation
-High dose reginmens
Coronary heart disease
-Unstable angina
-Acute myocardial infraction
-After thrombolytic therapy with rt-PA
22. Functions of Heparin:
An anticoagulant present in liver and produced
mainly by mast cells of liver.
Stimulates the release of lipoprotein lipase
enzyme that hydrolyses the absorbed fats.
It is an extra cellular compounds, entering in the
structure of receptors on the cell surface.It
participate in the cell adhesion and cell-cell
interaction.
23. Dermatan sulphate
Structure:
Disaccharide units composed of L-Iduronic acid
and N-acetyl galactosamine with sulfate on C6.
It is widely distributed in animal tissue, resembling
chondroitin sulfate and Heparan sulfate.
It has anti thrombotic properties similar to heparin.
25. Functions of Dermatan Sulphate:
It is a predominant glycan present in skin.
Dermatan sulfate may have roles
Coagulation,
Cardiovascular disease,
Carcinogenesis,
Infection,
Wound repair, and
26. Keratan sulfate (KS),also called Keratosulfat
Keratan Sulphate is either of two
glycosaminoglycans (I and II),consisting of repeating
disaccharides units of N-acetylglucosamine and
galactose,but differing slightly in carbohydrate content
and localization.
It occurs in cartilage, the cornea, and in the
nucleus pulposus and is also an accumulation product
in Morquio's syndrome.
27. KS types are to be composed of three regions
A linkage region, at one end of which the KS chain is linked
to the core protein.
A repeat region, composed of the -3Galβ1-4GlcNAcβ1-
repeating disaccharide unit and
A chain capping region, occurring at the opposite end of
the KS chain to the protein linkage region.
The designations KSI and KSII were originally assigned on the
basis of the tissue type from which the keratan sulfate was
isolated.
KSI was isolated from corneal tissue and KSII from skeletal tissue
The major differences occur in the way each KS type
is joined to its coreprotein.
29. Found in :
Loose connective tissue KS (type-1)
Cornea
Cartilage and
Bone.
30. Structure of keratan sulphate:
The disaccharide unit is composed of
(1) Galactose with sulfate on C6 and
(2 (N-acetyl glucosamine with sulfate on C6.
No uronic acid
31. Functions of Keratan Sulphate:
It occurs in cornea and skeletal tissues.
It keeps cornea transparent.
32. Isolation of Polysaccharide:
Polysaccharide can be isolated by ion exchange
chromatography.
Polysaccharide fraction was dissolved in distilled
water and loaded on DEAE-column.
The column was washed with water, then with
phosphate buffer pH 6.0 with increasing ionic
strength and finally with aqueous solution.
