Amylose sulfate

Painter and Morgan used poly(styrenesulfonic acid) 2 as catalyst for the selective hydrolysis of polysaccharides (2S). The polymer acid was up to twenty to thirty times more effective than hydrochloric acid in the case of polysaccharides containing free amino groups, but it was 30% less effective for the hydrolysis of unsubstituted starch 26. Obviously, the electrostatic attraction between the polymer and substrate enhanced the catalytic activity. More recently, Tal da reported that amylose sulfate catalyzed the hydrolysis of sucrose 74 times more efficiently than sulfuric acid (39). 

A. Richter and W. Wagenknecht, Synthesis of amylose acetates and amylose sulfates with high structural uniformity, Carbohydr. Res., 338 (2003) 1397-1401. 

High temperatures can break native S-S bonds and form new S-S bonds which can lock the protein into a denatured eonfiguration [89]. Low pH, sodium dodecyl sulfate. Tween 80, chaotropie salts, and exogenous proteins have been used to protect proteins from thermal inaetivation [90]. Ethylene glycol at 30-50% was used to protect the antiviral activity of P-interferon preparations [91]. Human serum albumin was used in recombinant human interferon-Psei-n which resulted in increased thermal stability [62]. Water-soluble polysaeeharides sueh as dextrans and amylose [92], as well as point-specific (site-directed) mutagenesis [93] have also been used to increase thermal stability of therapeutie proteins and peptides. 

The location of the metal cation (or cations) in alcoholates has been investigated by the method of substitutive methylation for the sodium derivatives of methyl a-D-glucopyranoside, amylose, and cellulose. The method assumes that methylation by either dimethyl sulfate or methyl iodide occurs only at an anionic oxygen atom. Lenziu methylated the mono-sodium alcoholates (prepared in boiling, butanolic sodium hydroxide by the... 

Starch fibrids are produced by spraying alkaline starch dispersion into an agitated, concentrated solution of ammonium sulfate.41,42 Amylose fibers or films are likewise produced by extmsion of a hot paste into a coagulating bath. Starch fibrids (starch pulp) can be utilized as a bonding additive in paper, but its use is rare. 

Microbiological action in starch dispersions results in a drop in pH, loss of viscosity and the development of odor. Retrogradation may be accelerated by the drop in pH or especially if butanol, which complexes with amylose, is generated via starch fermentation. Sulfate-reducing bacteria will cause black deposits due to reaction with iron in the process water. For quality control, preservatives are added to starch slurry, cooked starch, surface size and coating color. 

From the supernatant liquor, the amylopectin fraction was precipitated by adding sufficient magnesium sulfate to afford a total concentration of salt of 13.0% by wt. Allowing the precipitated amylopectin to remain in contact with the salt solution for 14 hours proved to be sufficient to make it perfectly insoluble in cold water. The amylopectin was then obtained in the dry state by the same technique used for the amylose precipitate. Po-tentiometric titration with iodine at 25.0° and measurement of the intrinsic viscosity at 25.00° were applied in order to characterize both fractions. 

Table VI shows the results of a number of these experiments, using different magnesium sulfate concentrations. The increase of fractionation efficiency with increase of the salt concentration is evident. Independent of the salt concentration, all experiments yield amylose fractions of maximum iodine-absorption capacity, as recrystallization with 1-butanol did not show any increase in the original values.

Mechanical Subfractionation of Amylose Particles Obtained by Fractional Precipitation of Potato Starch from an Aqueous Solution of Magnesium Sulfate... 

Fig. 3.—Phase Diagrams of Two Ternary Systems Amylose-Magnesium Sulfate-Water (Solid Curves) and Amylopectin-Magnesium Sulfate-Water (Dotted Curves).

Now, all of the evidence points to the fact that amylose phase-separation caused by magnesium sulfate is just one more example of this type of precipitation of a crystalline polymer. As the critical temperature of phase separation increases with increase in the salt concentration, and as increase of the former (in the case of polymer-nonsolvent-solvent systems) is nor-... 

Figure 5.5.1. A scatter plot of the intensity of ion with m/z =125 as a function of ion with m/z = 43 for (a) chitin, (b) chondroitin sulfate, (c) chitosan, (d) capsular polysaccharide from Neiseria meningitidis [47], (e) teichuronic acid from Bacillus subtilis [47], (f) carrageenan, (g) alginic acid, (h) amylose, (i) agarose.

Polysaccharides Hydrogen bonds and dipole-dipole interactions with hydroxyl groups of the sugar molecules are assumed to be the main interactions. In some cases, the helical structure of dextrins might be responsible for chiral recognition. Heparin, dextran sulfate, dermatan sulfate, streptomycin sulfate, amylose, chondroitin sulfate C, laminaran, dextrin sulfopropyl, and kanamycin sulfate. Doxylamine, laudanosine, naproxen, oxamniquine, pheniramine, primaquine, timepidium, trimetoquinol, etc. 

---