Dextran Chemische Eigenschaften,Einsatz,Produktion Methoden
R-S?tze Betriebsanweisung:
R20/21/22:Gesundheitssch?dlich beim Einatmen,Verschlucken und Berührung mit der Haut.
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
S-S?tze Betriebsanweisung:
S24/25:Berührung mit den Augen und der Haut vermeiden.
S37/39:Bei der Arbeit geeignete Schutzhandschuhe und Schutzbrille/Gesichtsschutz tragen.
S36:DE: Bei der Arbeit geeignete Schutzkleidung tragen.
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
Beschreibung
Dextrans are glucose polymers produced by bacteria linked in
an α-1,6 chain and having an α-1,3 or α-1,4 branch about every fifth residue. The specific
positioning of the branching varies by the bacterium producing it. The molecular weights of these
chains generally are 40 or 70 kDa (dextran-40 and dextran-70, respectively), and the compounds
work via an osmotic gradient similar to the colloids and hypertonic crystalloid solutions.
Dextrans have a longer intravascular
residence time
than albumin, which limits interstitial edema. As with the crystalloids and other colloids, the dextrans
have no oxygen-carrying capacity. Furthermore, because they are bacterial products, the dextrans
have the potential to be potent antigens and induce anaphylaxis.
Chemische Eigenschaften
white crystals or powder
Verwenden
Dextran is a polysaccharide composed of glucose molecules used as an antithrombotic to reduce blood viscosity and as a volume expander in anemia. Studies show that it inhibits the mannose receptor-med
iated clearance of tissue-type plasminogen activator (t-PA).
Definition
dextran: A glutinous glucose polymerproduced by certain bacteria. Itcan be made by fermenting sucrose(cane sugar) and is used as a thickeningagent, as a stabilizer in ice cream,and as a substitute for plasma inblood transfusions. Esters with sulphuricacid yield sodium salts thatare employed as anticoagulant drugs.
Allgemeine Beschreibung
Dextrans are polysaccharides with molecular weights ≥1,000 Dalton, with a linear backbone of α-linked D-glucopyranosyl repeating units. Dextrans are found as bacterial extracellular polysaccharides. They are synthesized from sucrose by
Leuconostoc mesenteroides and
Lactobacillus brevis. Bacteria employ dextran in biofilm formation or as a protective coating to evade host phagocytes in the case of pathogenic bacteria.
Dextran from
Leuconostoc mesenteroides (Mw: 12,000) may be used as an analytical standard to calibrate the column for gel permeation chromatography (GPC).
Mechanism of action
Sicherheitsprofil
Suspected carcinogen
with experimental carcinogenic data. When
heated to decomposition it emits acrid
smoke and fumes. See also other
DEXTRANS.
l?uterung methode
Solutions of dextran keep indefinitely at room temperature if 0.2mL of Roccal (10% alkyldimethylbenzylammonium chloride) or 2mg phenyl mercuric acetate are added per 100mL solution. This inhibits mould growth. [Scott & Melvin Anal Biochem 25 1656 1953.]
Dextran Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
