Dextrans structure

Representative dextran structures appear in 9.20, top left, 1 6 linked glucose units with a 1 4 branch top right, linear 1 6 linked glucose units with a 1 2 branch middle, linear chain with both 1 6 and 1 3 linkages bottom, linear chain of 1 6 linked glucose units with a 1 3 branch. All links are a-linkages. 

Fig. 9. Synthesis of a targetable dextran-adriamycin conjugate. Note that amino groups were introduced into the dextran structure, whereas the amino group of adriamycin was converted into a carboxylic group. According to [54]...

Keywords Functionalised dextran Structural analysis Prodrugs Nanostructures Bioactivity... 

Preliminary examinations of dextran structures were conducted by optical rotation, infrared spectroscopy and periodate-oxidation reactions. More detailed results can be achieved by methylation analysis [19]. The hydroxyl groups are methylated with methyl iodide after activation with sodium methylsulfinyl carbanion (Fig. 2). The methyl dextran is hydrolysed to the corresponding different methylated monosaccharides, which are furthermore reduced and peracetylated. The resulting alditol acetates of methylated sugars are separated by gas chromatography and identified by their retention times. In particular, a combined capillary gas-liquid chromatography/mass... 

Until complete, structural information is available for each of these dextrans, it is not possible to relate dextran structure to con A reactivity. However, such factors as polydispersity, molecular weight,369 frequency and nature of branching, type of a-D-glucosidic linkages, and, very important, the number of glycosyl residues in the exterior chains, all contribute to the con A reactivity of the polymer.362 The capacity for precipitate formation with con A is now virtually a standard procedure in studies on dextran structure.382,383... 

Neely, W. Brock, Dextran Structure and Synthesis, 15, 341 — 369 Neely, W. Brock, Infrared Spectra of Carbohydrates, 12, 13 — 33 Neuberg, Carl, Biochemical Reductions at the Expense of Sugars, 4, 75—117 Neufeld, Elizabeth F., and Hassid, W. Z., Biosynthesis of Saccharides from Glycopyranosyl Esters of Nucleotides ( Sugar Nucleotides ), 18, 309 - 356... 

Neely, W. Brock, Dextran Structure and Synthesis, 16, 341-369 Neely, W. Brock, Infrared Spectra of Carbohydrates, 12, 13-33... 

Krentsel L, Chaubet F, Rebrov A, et al. (1997). Anticoagulant activity of functionalized dextrans. Structure analyses of carboxymethylated dextran and first Monte Carlo simulations. Carbohyd. Polym. 33 63-71. 

The discussion of the structural studies in this Section are divided into two parts the first deals with the chemical elucidation of dextran structures, and the second, with the application of physicochemical measurements to the examination of network structures formed by association of dextran molecules. 

Fig. 2.—Schematic Representations of Possible Types of Dextran Structures. For clarity, short branch-chains are omitted. O = terminal, reducing-end residue — = secondary a-linkages — = chains of (1— 6)-linked [sometimes (l— 3)-linked] a-n-glucopyranosyl residues. ...

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