Dextran

Literature References: A term applied to polysaccharides produced by bacteria growing on a sucrose substrate, contg a backbone of D-glucose units linked predominantly a-D(1®6). Several organisms produce dextrans but only Leuconostoc mesenteroides and L. dextranicum (Lactobacteriaceae) have been used commercially. Chemical and physical properties of the dextrans vary with the methods of production. Native dextrans usually have high mol wt; lower mol wt clinical dextrans usually prepared by depolymerization of native dextrans or by synthesis. All dextrans are composed exclusively of a-D-glucopyranosyl units, differing only in degree of branching and chain length. Prepn: Tarr, Hibbert, Can. J. Res. 5, 414 (1931); Novak, Stoycos, US 2841578 (1958 to Commonwealth Eng. of Ohio). Enzymic synthesis: Sugg, Hehre, J. Immunol. 43, 119 (1942); Behrens, Ringpfeil, US 3044940 (1962 to Serum Werk Bernburg). The crude dextran may be isolated from the culture by precipitation with methanol. Continuous dialysis process: Shurter, US 2717853 (1955 to C.S.C.). Elimination of pyrogens: Levi, Lozinski, US 2762727 (1956 to Frosst). Method of producing clinical dextran: Novak, Witt, US 2972567 (1961). Structure studies: Fowler et al., Can. J. Res. B15, 486 (1937); Fairhead et al., ibid. B16, 151 (1938); Peat et al., J. Chem. Soc. 1939, 581; Goldstein, Whelan, ibid. 1962, 170, 176. 13C-NMR structure study: F. R. Seymour et al., Carbohydr. Res. 51, 179 (1976). Reviews: Evans, Hibbert, Adv. Carbohydr. Chem. 2, 204 (1946); Neely, ibid. 15, 341 (1960); Ricketts, Prog. Org. Chem. 5, 73 (1961); Murphy, Whistler, in Industrial Gums, R. L. Whistler, Ed. (Academic Press, New York, 2nd ed., 1973) pp 513-542.