Page 118 - Pharmd general phytochemistry I-Final2024_LEUCTERS

Source:
 It is formed by the action of transglucosylase enzyme system present in bacterium

Leuconostic mesenteroides on sucrose. The reaction can be summarized in the

following equation:

Primer Dextran

 Dextrans with clinical utility have an average molecular weight of 40,000, 70,000

and 75,000.

Chemical Composition
 Dextrans are long slender molecules with α-1,6 linkages and α -1,2; α -1,3 or α -1,4

branching, depending on the strain and species of bacteria employed.
 The branching is believed to occur every five glucose units.

Uses and Clinical Pharmacology
 Dextrans are used in cases of shock caused by hemorrhage, trauma or severe

burns.
 Dextran 40 (M.wt 40,000) is used as a plasma extender at 10% concentration.
 Dextran polymers function in-vivo by an osmotic effect similar to that of albumin.

The intravascular blood volume increases through the migration of water into the
vascular system to alleviate the hypertonicity caused by the intravenously
administered dextran.
 It is advantageous over some blood substitutes in being neutral, remains for a long
time in the blood circulation and have viscosity and osmotic pressure similar to
those of plasma.

Cellulose and Cellulose Derivatives

Occurrence:
 It is the chief polysaccharide of plant cell walls. It is chemically resistant to all

chemicals elaborated by the cell.
 Apart from being a pharmaceutical necessity, cellulose represent the core material

in paper and clothes industry.

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