Polysaccharides pullulan

Nonionic Polyethylene oxide Polyethylene glycol Polysaccharides Pullulans Dextrans Cellulosics Polyvinyl alcohol Polyacrylamide 0.1 M NaNOj... 

A good example of template copolycondensation has been described by Ogata et al Copolycondensation of 2,6-dimethyl pyridine dicarboxylate and dimethyl adipate with hexamethylene diamine was carried out in the presence of polysaccharide - Pullulane (mol. weight 30,000) used as a template. The reaction was carried out in DMSO at 60 C. It was found that the content of 2,6-dimethyl pyridine dicarboxylate units in the copolyamide, determined by NMR analysis, increased in the presence of Pullulane in comparison with the amount obtained in the absence of the template. This effect can be explained by preferential adsorption by the template of monomer having pyridine groups in comparison with the adsorption of dimethyl adipate. A set of experiments was carried out under the same conditions, but in the presence of poly(acrylonitrile) instead of Pullulane. The composition of copolyamides was the same as in copolycondensation without the template. 

Easily Soluble Polysaccharides. Pullulan with a DP of 250 a-D-gluco-pyranosyl units joined by 1 4 and 1 6 linkages in a linear chain is... 

Catley, B. J. (1971). Role of pH and nitrogen limitation in the elaboration of the extracellular polysaccharide pullulan by PuUularia puttulans. Applied Microbiology, 22, 650. ... 

The SEC partition coefficient [6] (.K sec) was measured on a Superose 6 column for three sets of well-characterized symmetrical solutes the compact, densely branched nonionic polysaccharide, Ficoll the flexible chain nonionic polysaccharide, pullulan and compact, anionic synthetic polymers, carboxylated starburst dendrimers. All three solutes display a congruent dependence of K ec on solute radius, R. In accord with a simple geometric model for SEC, all of these data conform to the same linear plot of i sEc versus R. This plot reveals the behavior of noninteracting spheres on this column. The mobile phase for the first two solutes was 0.2M NaH2P04-Na2HP04, pH 7.0. In order to ensure the suppression of electrostatic repulsive interactions between the dendrimer and the packing, the ionic strength was increased to 0.30M for that solute. 

The validity of the power law, eq 2, was established in all cases. For atactic polystyrene (a-PS) and polyethylene oxide (PEO) a was found to be 1.5, and rather remarkably, irrespective of solvent quality, in the few instances when the solvent was varied. A value of 1.7 for a has just been reported (9) for the good solvent bromobenzene (not used by us) from a different source. For the bacterial polysaccharide pullulan, which happened to be obtainable in comparatively sharp fractions, a was 1.8 in what is believed to be good solvent (iO). 

A related polysaccharide, pullulan, is conveniently discussed together with the amylaceous polysaccharides, as the enzymes used in the elucidation of its structure are the same as those used for starch and glycogen. 

As reported by Fuentes-Alventosa et al. [60], more complex silica-clay nanoarchitectures can also be prepared by sol-gel chemistry coupled with intercalation procedures combining montmorillonite and silica from TEOS, but in this case in the presence of a polysaccharide (pullulan). The resulting bionanocomposite is of... 

Pseudomonas amyloderamosa elaborates an isoamylase that specifically hydrolyzes the a-1 -> 6 branch linkages of starch [16-20]. Another enzyme that also will hydrolyze the a-1 6 branch linkages of starch is pullulanase, which is elaborated by a strain of A. aerogenes [20]. This enzyme is a hydrolase that specifically hydrolyzes the a-1 6 linkages of the linear polysaccharide, pullulan... 

The ->AGU are joined together by a-l,4-glucosi-dic linkages. Maltotriose syrup is derived from high - maltose syrup by cation-exchange resin chromatography. A by-product of this separation process is maltose solution of 98% purity. It is also available from hydrolysis of the polysaccharide ->pullulan by the debranching enzyme pullula-nase. 

TABLE 3 Binding Constant, K, for the Interaction Between the Liposomal Polysaccharide and the Bulk Polysaccharide (Pullulan-50) in the Aqueous 6.0% (w/w) PEO-20/8.0% (w/w) Pullulan-50 System... 

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