Dextran, acetate ethers

Deuterium-labelled glycogen, III, 246 Dextran, 2,3-dimethyl-D-gIucose from methylated, V, 161 Dextran acetate, II, 218 Dextran beers, IV, 333 Dextran esters, II, 218 Dextran ethers, II, 218 Dextran triacetate, II, 210, 212 Dextran tribenzoate, II, 210, 212 Dextrans... 

Reaction of carbohydrate with quaternary ammonium hydroxide Dextran acetate Ester derivative of dextran Dextran ether esters Mixed benzyl and butyl ethers... 

Dextran acetate Dextran benzyl ether Dextran benzyl ether Acetone-soluble benzyldextran Dextran ether Benzyl ether of dextran Lacquer with benzyl ether of dextran -etherify or esterify in me-Dextran dium benzyl -soft, rubbery ether ether -from separated dextran... 

The preparations of dextran, and certain ethers and esters of dextran have been the subjects of about fifteen recent patents. The dextran (of L. mesenteroides or dextraniczim) may be precipitated first from the culture by the addition of ethanol or acetone, or the culture itself may be treated directly with the appropriate halide and sodium hydroxide in either a single stage or a two-stage procedure. The benzyl ether of dextran, formed by the reaction of dextran with benzyl chloride and sodium hydroxide at 75-185° for three to ten hours, is soluble in acetone and other solvents, and may be used in lacquers. Mixed ether and ester derivatives of dextran, e. g., benzyl and phthalate or butyl and benzoate, have been used for forming films, coatings or molded products. A preparation of dextran acetate has also been patented. ... 

To 200 mL acetone was added 4.35 g dextran acetate A, which was methylated with NaOH (30%, 300 mL) and 110 mL dimethyl sulfate over a period of 3 h. The bath temperature was kept at 25°C for the first 2 h, and at 55°C for 1 h it was then raised to 100°C for 0.5 h. The excess alkali was neutralized, and the reaction mixture was dialyzed. The dialyzed material was concentrated to a small volume, and the methylation was repeated four times in the same way with the bath temperature maintained at 55°C acetone was added in to keep the product in solution. After the fifth methylation the product was extracted with chloroform, and the extract was washed with dilute acetic acid and water and concentrated to give 3.39 g syrup. The syrupy product was methylated with 50 mL methyl iodide (50 mL) and 6 g silver oxide, added in 12 portions under continual stirring and refluxing for 22 h. The product was extracted with chloroform, and after the removal of solvent it was remethylated four times in the same manner to give 1.96 g product with a methoxyl content of 44.93%. On fractionation of the methylated dextran from chloroform with petroleum ether, 90% of the product precipitated at 90-92% petroleum ether, a second... 

Dicarboxyethyl dextran 2-(Diethylamino)ethyl 2-Hydroxyoctyl- and 2-hydroxydodecyl Poly(ethylene glycol)-alkyl dextran ether 2-Hydroxy-3-phenoxy propyl dextran ethers Dynamic light scattering N,N- Dime thylace tamide 4-N.N-Dimethylaminopyridine Dextran propionate acetate... 

Numerous ethers of cellulose, starch, and bacterial dextran are of established or potential industrial importance. (See also Chapter XII.) Treatment of the polysaccharides with alkali and methyl chloride, ethyl chloride, benzyl chloride, ethylene oxide (or ethylene chlorohydrin), sodium chloro-acetate, and allyl bromide gives, respectively, the methyl, ethyl, benzyl, hydroxy ethyl, carboxy methyl, and allyl ethers. The cellulose derivatives... 

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