What is Dextran?

Identification

Product Name:    Dextran

Synonyms:    Dextran 75,000 Mw, Pryogen Free;Dextrane2000;Dextran, high fraction, for biochemistry;MUCROSE;NATIVE DEXTRAN;POLY[(1,6)-ALPHA-D-GLUCOSE];DEXTRAN,150,000,POWDER;DEXTRAN,250,000,POWDER    

CAS:    9004-54-0    

MF:    C17H32O10    

MW:    396.42998    

EINECS:    232-677-5

Properties

Melting point     483 °C (decomp)    

alpha     198 º    

refractive index     185 ° (C=6, H2O)    

storage temp.     2-8°C    

solubility     H2O: soluble50mg/mL, clear to very slightly hazy, colorless to faintly yellow    

form     Solid    

color     White to slightly off-white    

PH    2 - 10    

Water Solubility     Soluble in water, dimethyl sulfoxide, ethylene glycol and glycerol.    

Introduction

Dextran is a complex branched glucan (polysaccharide derived from the condensation of glucose), originally derived from wine. IUPAC defines dextrans as "Branched poly-α-d-glucosides of microbial origin having glycosidic bonds predominantly C-1 → C-6".[1] Dextran chains are of varying lengths (from 3 to 2000 kilodaltons).

The polymer main chain consists of α-1,6 glycosidic linkages between glucose monomers, with branches from α-1,3 linkages. This characteristic branching distinguishes a dextran from a dextrin, which is a straight chain glucose polymer tethered by α-1,4 or α-1,6 linkages. Dextran is a generic term for a family of glucans made by polymerization of the α-d-glucopyranosyl moiety of sucrose in a reaction catalyzed by the enzyme dextransucrase. The common feature is a preponderance of (1 → 6)-linked α-d-glucopyranosyl units.

Uses

High-molecular weight dextran is a plasma volume expander made from natural sources of sugar (glucose). It works by restoring blood plasma lost through severe bleeding. Severe blood loss can decrease oxygen levels and can lead to organ failure, brain damage, coma, and possibly death. Plasma is needed to circulate red blood cells that deliver oxygen throughout the body.

Dextran is used to treat hypovolemia (decreased volume of circulating blood plasma), that can result from surgery, trauma or injury, severe burns, or other causes of bleeding.

Dextran may also be used for purposes not listed in this medication guide.

Dextran 70 is on the WHO Model List of Essential Medicines, the most important medications needed in a health system. Medicinally it is used as an antithrombotic (antiplatelet), to reduce blood viscosity, and as a volume expander in hypovolaemia.

Microsurgery

These agents are used commonly by microsurgeons to decrease vascular thrombosis. The antithrombotic effect of dextran is mediated through its binding of erythrocytes, platelets, and vascular endothelium, increasing their electronegativity and thus reducing erythrocyte aggregation and platelet adhesiveness. Dextrans also reduce factor VIII-Ag Von Willebrand factor, thereby decreasing platelet function. Clots formed after administration of dextrans are more easily lysed due to an altered thrombus structure (more evenly distributed platelets with coarser fibrin[citation needed]). By inhibiting α-2 antiplasmin, dextran serves as a plasminogen activator, so possesses thrombolytic features.

Other medical uses

Dextran is used in some eye drops as a lubricant. and in certain intravenous fluids to solubilize other factors, such as iron (in a solution known as Iron Dextran).

Intravenous solutions with dextran function both as volume expanders and means of parenteral nutrition. Such a solution provides an osmotically neutral fluid that once in the body is digested by cells into glucose and free water. It is occasionally used to replace lost blood in emergency situations, when replacement blood is not available, but must be used with caution as it does not provide necessary electrolytes and can cause hyponatremia or other electrolyte disturbances.

Dextran also increases blood sugar levels.

Dextran can be used in an ATPS for PEGylation