Alginic acid, fractionation

Aldotriouronic acids, 73 Alginic acid, fractionation, 55 L-guluronic acid in, 88 Alkaloids, biosynthesis of, 269 Allose, 2-amino-2-deoxy-n-, derivatives of, 191... 

Bovine serum albumin (BSA), fraction V, B-lactoglobulin, gum arabic, and alginic acid, low viscosity, were purchased from Sigma Chemical Co. (St. Louis, MO). The proteins were used without further purification. Aqueous solutions of gum arabic and alginic acid were filtered successively through cellulosic membrane filters of 5.0 fan and 0.45 fan pore size to remove insoluble particulate matter. The filtrate was frozen and lyophilized prior to use. 

The molecular weight of the sodium salt of alginic acid has been determined by measurements of osmotic pressure in sodium chloride solution.88 The n/C versus C curve was found to be independent of salt concentration for values between 0.2 N and 0.5 JV, and the slope of the curve was the same for a series of seven fractions with values of molecular weight between 48,000 and 186,000 (220-860 D-mannuronic acid units). Intrinsic viscosity measurements showed the coefficient a in the modified Staudinger s equation88 to be 1.0 and the approximate value of Km to be 15(10)-4. 

Haug, A. Fractionation of alginic acid. Acta. Chem. Scand. 13, 601-613 (1959)... 

As well as degrading alginate, the fractions degraded a poly-L-guluronide and a polyuronide composed of D-mannuronic and L-guluronic acid residues, but not a poly-D-mannuronide, so that they appear to be endo-poly(L-guluronicacid) lyases. The properties of these enzymes have been investigated. ... 

Pipette 30 ml of the injection solution on to a previously prepared oxycellulose or alginic acid column (see p. 461) and allow to pass through the column at a flow rate of 1 to 3 ml per minute. Wash with at least three portions of 25 ml of water, collecting the eluate and washings. Dilute this fraction suitably with water and determine the bactericide spectrophotometrically (see p. 519). 

A number of hydroxylated water soluble polymers were examined as coreactants with polymer 52 in the absence of calcium alginate, and were judged on the basis of the rate of gel formation and the physical properties of the gel These polymers included sodium alginate, polyvinyl alcohol, and copolymers of HEMA with MAA. Of the polymers tested, best results were obtained with polymer 10a, a copolymer of HEMA with a mole fraction of about 10% MAA, which rapidly produced an elastic gel on exposure to polymer 52 in solution. Simple condensation of the carboxyls in polymer 10a with the epoxide functionality was ruled out as a competing reaction due to the measurable but slow reaction between polymer 52 and poly methacrylic acid. It is, therefore, likely... 

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